Trial Outcomes & Findings for Heart Rate Variability and Emotion Regulation (NCT NCT03458910)

NCT ID: NCT03458910

Last Updated: 2025-07-23

Results Overview

The strength of resting-state functional connectivity was measured by correlation coefficients. Values represent the correlation of BOLD time-series between mPFC and the right amygdala. Higher values indicate greater connectivity.

Recruitment status

TERMINATED

Study phase

NA

Target enrollment

193 participants

Primary outcome timeframe

Time 1 (Baseline), Time 2 (5 weeks)

Results posted on

2025-07-23

Participant Flow

Participant milestones

Participant milestones
Measure
Younger HRV-increase Group
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Younger HRV-decrease Group
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Older HRV-decrease Group
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Overall Study
STARTED
63
58
37
35
Overall Study
COMPLETED
56
50
28
28
Overall Study
NOT COMPLETED
7
8
9
7

Reasons for withdrawal

Reasons for withdrawal
Measure
Younger HRV-increase Group
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Younger HRV-decrease Group
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Older HRV-decrease Group
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Overall Study
Withdrawal by Subject
7
8
6
4
Overall Study
Study halted due to risk of catching COVID-19
0
0
3
3

Baseline Characteristics

Heart Rate Variability and Emotion Regulation

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Younger HRV-increase Group
n=63 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Younger HRV-decrease Group
n=58 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=37 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Older HRV-decrease Group
n=35 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Total
n=193 Participants
Total of all reporting groups
Age, Categorical
<=18 years
6 Participants
n=99 Participants
4 Participants
n=107 Participants
0 Participants
n=206 Participants
0 Participants
n=7 Participants
10 Participants
n=31 Participants
Age, Categorical
Between 18 and 65 years
57 Participants
n=99 Participants
54 Participants
n=107 Participants
21 Participants
n=206 Participants
14 Participants
n=7 Participants
146 Participants
n=31 Participants
Age, Categorical
>=65 years
0 Participants
n=99 Participants
0 Participants
n=107 Participants
16 Participants
n=206 Participants
21 Participants
n=7 Participants
37 Participants
n=31 Participants
Age, Continuous
22.71 years
STANDARD_DEVIATION 2.47 • n=99 Participants
22.66 years
STANDARD_DEVIATION 3.17 • n=107 Participants
65.03 years
STANDARD_DEVIATION 8.29 • n=206 Participants
65.66 years
STANDARD_DEVIATION 5.88 • n=7 Participants
38.68 years
STANDARD_DEVIATION 21.28 • n=31 Participants
Sex: Female, Male
Female
31 Participants
n=99 Participants
29 Participants
n=107 Participants
24 Participants
n=206 Participants
21 Participants
n=7 Participants
105 Participants
n=31 Participants
Sex: Female, Male
Male
32 Participants
n=99 Participants
29 Participants
n=107 Participants
13 Participants
n=206 Participants
14 Participants
n=7 Participants
88 Participants
n=31 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
2 Participants
n=99 Participants
5 Participants
n=107 Participants
2 Participants
n=206 Participants
3 Participants
n=7 Participants
12 Participants
n=31 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
55 Participants
n=99 Participants
48 Participants
n=107 Participants
35 Participants
n=206 Participants
31 Participants
n=7 Participants
169 Participants
n=31 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
6 Participants
n=99 Participants
5 Participants
n=107 Participants
0 Participants
n=206 Participants
1 Participants
n=7 Participants
12 Participants
n=31 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=99 Participants
0 Participants
n=107 Participants
0 Participants
n=206 Participants
0 Participants
n=7 Participants
0 Participants
n=31 Participants
Race (NIH/OMB)
Asian
43 Participants
n=99 Participants
38 Participants
n=107 Participants
5 Participants
n=206 Participants
6 Participants
n=7 Participants
92 Participants
n=31 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=99 Participants
0 Participants
n=107 Participants
0 Participants
n=206 Participants
0 Participants
n=7 Participants
0 Participants
n=31 Participants
Race (NIH/OMB)
Black or African American
4 Participants
n=99 Participants
0 Participants
n=107 Participants
12 Participants
n=206 Participants
2 Participants
n=7 Participants
18 Participants
n=31 Participants
Race (NIH/OMB)
White
9 Participants
n=99 Participants
13 Participants
n=107 Participants
18 Participants
n=206 Participants
25 Participants
n=7 Participants
65 Participants
n=31 Participants
Race (NIH/OMB)
More than one race
2 Participants
n=99 Participants
2 Participants
n=107 Participants
2 Participants
n=206 Participants
1 Participants
n=7 Participants
7 Participants
n=31 Participants
Race (NIH/OMB)
Unknown or Not Reported
5 Participants
n=99 Participants
5 Participants
n=107 Participants
0 Participants
n=206 Participants
1 Participants
n=7 Participants
11 Participants
n=31 Participants
Region of Enrollment
United States
63 Participants
n=99 Participants
58 Participants
n=107 Participants
37 Participants
n=206 Participants
35 Participants
n=7 Participants
193 Participants
n=31 Participants

PRIMARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

The strength of resting-state functional connectivity was measured by correlation coefficients. Values represent the correlation of BOLD time-series between mPFC and the right amygdala. Higher values indicate greater connectivity.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=47 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=49 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
mPFC-right Amygdala Resting-state Functional Connectivity for Younger Adults (ANOVA)
Time 1
0.086 correlation coefficients
Standard Error 0.015
0.104 correlation coefficients
Standard Error 0.105
mPFC-right Amygdala Resting-state Functional Connectivity for Younger Adults (ANOVA)
Time 2
0.090 correlation coefficients
Standard Error 0.015
0.116 correlation coefficients
Standard Error 0.015

PRIMARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

The strength of resting-state functional connectivity was measured by correlation coefficients. Values represent the correlation of BOLD time-series between mPFC and the right amygdala. Higher values indicate greater connectivity.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=25 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=26 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
mPFC-right Amygdala Resting-state Functional Connectivity for Older Adults (ANOVA)
Time 1
0.140 correlation coefficients
Standard Error 0.046
0.109 correlation coefficients
Standard Error 0.045
mPFC-right Amygdala Resting-state Functional Connectivity for Older Adults (ANOVA)
Time 2
0.095 correlation coefficients
Standard Error 0.047
0.125 correlation coefficients
Standard Error 0.046

PRIMARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

The strength of resting-state functional connectivity between mPFC and the right amygdala was measured by correlation coefficients. The difference in functional connectivity between the two time points (Time 2 - Time 1) was calculated. Higher values indicate greater connectivity at Time 2 than Time 1 (or post- than pre-intervention).

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=47 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=49 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
mPFC-right Amygdala Resting-state Functional Connectivity for Younger Adults (Post-Pre)
-0.016 correlation coefficients
Standard Error 0.024
0.011 correlation coefficients
Standard Error 0.022

PRIMARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

The strength of resting-state functional connectivity between mPFC and the right amygdala was measured by correlation coefficients. The difference in functional connectivity between the two time points (Time 2 - Time 1) was calculated. Higher values indicate greater connectivity at Time 2 than Time 1 (or post- than pre-intervention).

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=25 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=26 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
mPFC-right Amygdala Resting-state Functional Connectivity for Older Adults (Post-Pre)
-0.045 correlation coefficients
Standard Error 0.046
0.016 correlation coefficients
Standard Error 0.072

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Emotional intensity ratings, which participants reported during the emotion regulation task inside MRI scanner before and after intervention. The ratings ranged from 1 through 4, and 4 represents strongest intensity.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=39 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=44 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Emotion Regulation in Younger Adults (Behavior)
Time 1: viewing
2.309 score on a scale
Standard Error 0.089
2.073 score on a scale
Standard Error 0.084
Emotion Regulation in Younger Adults (Behavior)
Time 1: down-regulation
1.822 score on a scale
Standard Error 0.085
1.841 score on a scale
Standard Error 0.080
Emotion Regulation in Younger Adults (Behavior)
Time 1: up-regulation
3.271 score on a scale
Standard Error 0.076
3.141 score on a scale
Standard Error 0.072
Emotion Regulation in Younger Adults (Behavior)
Time 2: down-regulation
1.959 score on a scale
Standard Error 0.080
1.861 score on a scale
Standard Error 0.075
Emotion Regulation in Younger Adults (Behavior)
Time 2: viewing
2.427 score on a scale
Standard Error 0.083
1.964 score on a scale
Standard Error 0.078
Emotion Regulation in Younger Adults (Behavior)
Time 2: up-regulation
3.395 score on a scale
Standard Error 0.074
3.269 score on a scale
Standard Error 0.070

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Emotional intensity ratings, which participants reported during the emotion regulation task inside MRI scanner before and after intervention. The ratings ranged from 1 through 4, and 4 represents strongest intensity.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=19 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=18 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Emotion Regulation in Older Adults (Behavior)
Time 2: viewing
2.695 score on a scale
Standard Error 0.162
2.668 score on a scale
Standard Error 0.116
Emotion Regulation in Older Adults (Behavior)
Time 2: up-regulation
3.155 score on a scale
Standard Error 0.097
3.279 score on a scale
Standard Error 0.069
Emotion Regulation in Older Adults (Behavior)
Time 1: down-regulation
1.973 score on a scale
Standard Error 0.119
2.059 score on a scale
Standard Error 0.085
Emotion Regulation in Older Adults (Behavior)
Time 1: viewing
2.511 score on a scale
Standard Error 0.134
2.586 score on a scale
Standard Error 0.096
Emotion Regulation in Older Adults (Behavior)
Time 1: up-regulation
3.022 score on a scale
Standard Error 0.121
3.117 score on a scale
Standard Error 0.087
Emotion Regulation in Older Adults (Behavior)
Time 2: down-regulation
2.061 score on a scale
Standard Error 0.122
2.115 score on a scale
Standard Error 0.087

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

We measured percent changes (%) in BOLD activity in the left amygdala region during emotion down-regulation, viewing, and up-regulation before and after intervention. The viewing condition was used as a baseline during the task. The change is represented by %.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=39 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=45 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Left Amygdala BOLD Activity During Emotion Regulation in Younger Adults
Time 1: down-regulation
0.024 Percent changes (%) in BOLD signal
Standard Error 0.023
0.032 Percent changes (%) in BOLD signal
Standard Error 0.022
Left Amygdala BOLD Activity During Emotion Regulation in Younger Adults
Time 1: viewing
0.048 Percent changes (%) in BOLD signal
Standard Error 0.035
0.029 Percent changes (%) in BOLD signal
Standard Error 0.023
Left Amygdala BOLD Activity During Emotion Regulation in Younger Adults
Time 1: up-regulation
0.095 Percent changes (%) in BOLD signal
Standard Error 0.028
0.107 Percent changes (%) in BOLD signal
Standard Error 0.026
Left Amygdala BOLD Activity During Emotion Regulation in Younger Adults
Time 2: down-regulation
0.021 Percent changes (%) in BOLD signal
Standard Error 0.022
0.027 Percent changes (%) in BOLD signal
Standard Error 0.021
Left Amygdala BOLD Activity During Emotion Regulation in Younger Adults
Time 2: viewing
-0.020 Percent changes (%) in BOLD signal
Standard Error 0.021
0.018 Percent changes (%) in BOLD signal
Standard Error 0.019
Left Amygdala BOLD Activity During Emotion Regulation in Younger Adults
Time 2: up-regulation
0.074 Percent changes (%) in BOLD signal
Standard Error 0.029
0.121 Percent changes (%) in BOLD signal
Standard Error 0.027

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

We measured percent changes (%) in BOLD activity in the left amygdala region during emotion down-regulation, viewing, and up-regulation before and after intervention. The viewing condition was used as a baseline during the task. The change is represented by %.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=20 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=21 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Left Amygdala BOLD Activity During Emotion Regulation in Older Adults
Time 1: down-regulation
-0.028 Percent changes (%) in BOLD signal
Standard Error 0.043
-0.069 Percent changes (%) in BOLD signal
Standard Error 0.041
Left Amygdala BOLD Activity During Emotion Regulation in Older Adults
Time 1: viewing
-0.006 Percent changes (%) in BOLD signal
Standard Error 0.040
-0.092 Percent changes (%) in BOLD signal
Standard Error 0.039
Left Amygdala BOLD Activity During Emotion Regulation in Older Adults
Time 1: up-regulation
0.067 Percent changes (%) in BOLD signal
Standard Error 0.053
-0.043 Percent changes (%) in BOLD signal
Standard Error 0.052
Left Amygdala BOLD Activity During Emotion Regulation in Older Adults
Time 2: down-regulation
-0.035 Percent changes (%) in BOLD signal
Standard Error 0.038
-0.068 Percent changes (%) in BOLD signal
Standard Error 0.037
Left Amygdala BOLD Activity During Emotion Regulation in Older Adults
Time 2: viewing
-0.013 Percent changes (%) in BOLD signal
Standard Error 0.031
-0.004 Percent changes (%) in BOLD signal
Standard Error 0.030
Left Amygdala BOLD Activity During Emotion Regulation in Older Adults
Time 2: up-regulation
0.036 Percent changes (%) in BOLD signal
Standard Error 0.032
-0.013 Percent changes (%) in BOLD signal
Standard Error 0.031

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

We measured percent changes (%) in BOLD activity in the right amygdala region during emotion down-regulation, viewing, and up-regulation before and after intervention. The viewing condition was used as a baseline during the task. The change is represented by %.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=39 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=45 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Right Amygdala BOLD Activity During Emotion Regulation in Younger Adults
Time 2: up-regulation
0.068 Percent changes (%) in BOLD signal
Standard Error 0.027
0.106 Percent changes (%) in BOLD signal
Standard Error 0.025
Right Amygdala BOLD Activity During Emotion Regulation in Younger Adults
Time 1: down-regulation
0.018 Percent changes (%) in BOLD signal
Standard Error 0.023
0.019 Percent changes (%) in BOLD signal
Standard Error 0.021
Right Amygdala BOLD Activity During Emotion Regulation in Younger Adults
Time 1: viewing
0.039 Percent changes (%) in BOLD signal
Standard Error 0.022
0.032 Percent changes (%) in BOLD signal
Standard Error 0.021
Right Amygdala BOLD Activity During Emotion Regulation in Younger Adults
Time 1: up-regulation
0.074 Percent changes (%) in BOLD signal
Standard Error 0.025
0.054 Percent changes (%) in BOLD signal
Standard Error 0.024
Right Amygdala BOLD Activity During Emotion Regulation in Younger Adults
Time 2: down-regulation
0.017 Percent changes (%) in BOLD signal
Standard Error 0.028
0.076 Percent changes (%) in BOLD signal
Standard Error 0.026
Right Amygdala BOLD Activity During Emotion Regulation in Younger Adults
Time 2: viewing
-0.003 Percent changes (%) in BOLD signal
Standard Error 0.029
0.073 Percent changes (%) in BOLD signal
Standard Error 0.027

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

We measured percent changes (%) in BOLD activity in the right amygdala region during emotion down-regulation, viewing, and up-regulation before and after intervention. The viewing condition was used as a baseline during the task. The change is represented by %.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=20 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=21 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Right Amygdala BOLD Activity During Emotion Regulation in Older Adults
Time 1: down-regulation
-0.014 Percent changes (%) in BOLD signal
Standard Error 0.053
-0.058 Percent changes (%) in BOLD signal
Standard Error 0.052
Right Amygdala BOLD Activity During Emotion Regulation in Older Adults
Time 1: viewing
-0.027 Percent changes (%) in BOLD signal
Standard Error 0.030
0.005 Percent changes (%) in BOLD signal
Standard Error 0.029
Right Amygdala BOLD Activity During Emotion Regulation in Older Adults
Time 2: down-regulation
-0.004 Percent changes (%) in BOLD signal
Standard Error 0.032
-0.038 Percent changes (%) in BOLD signal
Standard Error 0.031
Right Amygdala BOLD Activity During Emotion Regulation in Older Adults
Time 1: up-regulation
0.062 Percent changes (%) in BOLD signal
Standard Error 0.047
0.041 Percent changes (%) in BOLD signal
Standard Error 0.045
Right Amygdala BOLD Activity During Emotion Regulation in Older Adults
Time 2: viewing
0.001 Percent changes (%) in BOLD signal
Standard Error 0.027
-0.005 Percent changes (%) in BOLD signal
Standard Error 0.027
Right Amygdala BOLD Activity During Emotion Regulation in Older Adults
Time 2: up-regulation
0.024 Percent changes (%) in BOLD signal
Standard Error 0.039
0.006 Percent changes (%) in BOLD signal
Standard Error 0.038

SECONDARY outcome

Timeframe: one time point: at study completion, which is the end of 5-week training

Population: Population analyzed was composed by all randomization subjects who completed the decision making task, who were unfamiliar with the task and whose data quality was sufficient for data analysis.

The decision-making ability was measured by multiple-choice responses during a computer-based task. Median percentage of acceptance of unfair offers and fair offers were calculated. A higher percentage of accepted both unfair and fair offers points toward more rational decision-making and likely better emotion regulation. This task was administered only at post-intervention (but not pre-intervention).

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=33 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=35 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Decision-making for Younger Adults at Post Intervention (Behavior)
percentage of acceptance of unfair offers
33.33 percentage of offers
Interval 5.72 to 80.21
33.33 percentage of offers
Interval 5.56 to 72.22
Decision-making for Younger Adults at Post Intervention (Behavior)
percentage of acceptance of fair offers
100 percentage of offers
Interval 100.0 to 100.0
100 percentage of offers
Interval 100.0 to 100.0

SECONDARY outcome

Timeframe: one time point: at study completion, which is the end of 5-week training

Population: Population analyzed was composed by all randomization subjects who completed the decision making task, whose data quality was sufficient for data analysis and who were unfamiliar with the task.

We measured percent changes (%) in BOLD activity in the dorsal anterior cingulate cortex and anterior insula during a computer-based decision-making task. Higher values indicate greater activity.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=30 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=31 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Decision-making for Younger Adults (fMRI)
Dorsal anterior cingulate cortex activation
0.0177 Percent changes (%) in BOLD signal
Standard Error 0.0278
0.1073 Percent changes (%) in BOLD signal
Standard Error 0.0221
Decision-making for Younger Adults (fMRI)
Anterior insula activation
0.0135 Percent changes (%) in BOLD signal
Standard Error 0.0229
0.0740 Percent changes (%) in BOLD signal
Standard Error 0.0214

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Emotional well-being measured by the Profile of Mood States (POMS) for younger adults. The POMS consists of 40 items that are rated on a 5-point scale ranging from "0=not at all" to "4=extremely. Total Mood Disturbance (TMD) was calculated by summing the totals for the negative items and then subtracting the totals for the positive items. A constant (i.e., 100) was added to the TMD formula in order to eliminate negative scores. Higher scores indicate more negative mood states. The scores range from 56 and 216.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=50 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=53 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Mood for Younger Adults
Time 1
93.560 score on a scale
Standard Deviation 18.307
92.604 score on a scale
Standard Deviation 14.270
Mood for Younger Adults
Time 2
86.540 score on a scale
Standard Deviation 18.967
89.726 score on a scale
Standard Deviation 18.710

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Emotional well-being measured by the Profile of Mood States (POMS) for older adults. The POMS consists of 40 items that are rated on a 5-point scale ranging from "0=not at all" to "4=extremely. Total Mood Disturbance (TMD) was calculated by summing the totals for the negative items and then subtracting the totals for the positive items. A constant (i.e., 100) was added to the TMD formula in order to eliminate negative scores. Higher scores indicate more negative mood states. The scores range from 56 and 216.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=28 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=27 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Mood for Older Adults
Time 1
90.250 score on a scale
Standard Deviation 17.037
87.167 score on a scale
Standard Deviation 17.435
Mood for Older Adults
Time 2
87.536 score on a scale
Standard Deviation 18.339
79.852 score on a scale
Standard Deviation 12.440

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Emotional well-being measured by the Center for Epidemiological Studies Depression Scale (CES-D) for younger adults. The CES-D consists of 20 items that are rated on a scale of 0 to 3 (0 = Rarely or None of the Time, 1 = Some or Little of the Time, 2 = Moderately or Much of the time, 3 = Most or Almost All the Time). Possible range of scores is 0 to 60, with the higher scores indicating more depressive symptoms.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=49 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=55 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Depression for Younger Adults
Time 1
14.571 score on a scale
Standard Deviation 9.372
16.164 score on a scale
Standard Deviation 8.046
Depression for Younger Adults
Time 2
11.837 score on a scale
Standard Deviation 8.880
13.218 score on a scale
Standard Deviation 8.774

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Emotional well-being measured by the Center for Epidemiological Studies Depression Scale (CES-D) for older adults. The CES-D consists of 20 items that are rated on a scale of 0 to 3 (0 = Rarely or None of the Time, 1 = Some or Little of the Time, 2 = Moderately or Much of the time, 3 = Most or Almost All the Time). Possible range of scores is 0 to 60, with the higher scores indicating more depressive symptoms.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=28 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=27 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Depression for Older Adults
Time 1
14.143 score on a scale
Standard Deviation 9.816
8.852 score on a scale
Standard Deviation 7.383
Depression for Older Adults
Time 2
11.964 score on a scale
Standard Deviation 8.963
6.481 score on a scale
Standard Deviation 4.839

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Emotional well-being measured by the State Anxiety Inventory (SAI) for younger adults. The SAI consists of 20 items that are rated on a 4-point scale as follows: 1) not at all, 2) somewhat, 3) moderately so, and 4) very much so. Scores range from 20 to 80, with higher scores indicating greater state anxiety.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=49 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=53 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
State Anxiety for Younger Adults
Time 1
38.122 score on a scale
Standard Deviation 11.245
38.566 score on a scale
Standard Deviation 10.233
State Anxiety for Younger Adults
Time 2
36.347 score on a scale
Standard Deviation 11.816
37.972 score on a scale
Standard Deviation 10.511

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Emotional well-being measured by the State Anxiety Inventory (SAI) for older adults. The SAI consists of 20 items that are rated on a 4-point scale as follows: 1) not at all, 2) somewhat, 3) moderately so, and 4) very much so. Scores range from 20 to 80, with higher scores indicating greater state anxiety.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=27 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=28 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
State Anxiety for Older Adults
Time 1
33.889 score on a scale
Standard Deviation 11.078
31.786 score on a scale
Standard Deviation 8.741
State Anxiety for Older Adults
Time 2
33.963 score on a scale
Standard Deviation 10.082
30.143 score on a scale
Standard Deviation 7.966

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Emotional well-being measured by the Trait Anxiety Inventory (TAI) for younger adults. The TAI consists of 20 items that are rated on a 4-point scale as follows: 1) not at all, 2) somewhat, 3) moderately so, and 4) very much so. Scores range from 20 to 80, with higher scores indicating greater trait anxiety.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=49 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=55 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Trait Anxiety for Younger Adults
Time 1
41.306 score on a scale
Standard Deviation 12.582
42.473 score on a scale
Standard Deviation 9.933
Trait Anxiety for Younger Adults
Time 2
38.510 score on a scale
Standard Deviation 10.679
38.909 score on a scale
Standard Deviation 9.487

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Emotional well-being measured by the Trait Anxiety Inventory (TAI) for older adults. The TAI consists of 20 items that are rated on a 4-point scale as follows: 1) not at all, 2) somewhat, 3) moderately so, and 4) very much so. Scores range from 20 to 80, with higher scores indicating greater trait anxiety.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=27 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=28 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Trait Anxiety for Older Adults
Time 1
38.815 score on a scale
Standard Deviation 12.830
33.821 score on a scale
Standard Deviation 11.039
Trait Anxiety for Older Adults
Time 2
36.093 score on a scale
Standard Deviation 10.517
31.929 score on a scale
Standard Deviation 9.071

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Difference in stress recovery elicited by standard cognitive tasks, as assessed by change in systolic blood pressure from cognitive tasks to recovery rest

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=45 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=50 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Recovery (Systolic Blood Pressure) for Younger Adults
Time 1
-3.253 mmHg
Standard Deviation 6.465
-2.993 mmHg
Standard Deviation 8.176
Stress Recovery (Systolic Blood Pressure) for Younger Adults
Time 2
-0.702 mmHg
Standard Deviation 10.165
-1.973 mmHg
Standard Deviation 6.728

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Difference in stress recovery elicited by standard cognitive tasks, as assessed by change in systolic blood pressure from cognitive tasks to recovery rest

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=22 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=23 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Recovery (Systolic Blood Pressure) for Older Adults
Time 1
-6.650 mmHg
Standard Deviation 6.060
-6.464 mmHg
Standard Deviation 19.150
Stress Recovery (Systolic Blood Pressure) for Older Adults
Time 2
-4.380 mmHg
Standard Deviation 7.402
-4.592 mmHg
Standard Deviation 17.651

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Difference in stress recovery elicited by standard cognitive tasks, as assessed by change in heart rate from cognitive tasks to recovery rest

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=30 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=31 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Recovery (Heart Rate) for Younger Adults
Time 1
-1.870 beats per minute
Standard Deviation 4.133
-3.851 beats per minute
Standard Deviation 6.585
Stress Recovery (Heart Rate) for Younger Adults
Time 2
-1.486 beats per minute
Standard Deviation 3.734
-2.302 beats per minute
Standard Deviation 4.658

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Difference in stress recovery elicited by standard cognitive tasks, as assessed by change in heart rate from cognitive tasks to recovery rest

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=16 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=13 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Recovery (Heart Rate) for Older Adults
Time 1
-2.188 beats per minute
Standard Deviation 2.111
-3.921 beats per minute
Standard Deviation 4.760
Stress Recovery (Heart Rate) for Older Adults
Time 2
-1.267 beats per minute
Standard Deviation 2.894
-2.716 beats per minute
Standard Deviation 2.921

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Difference in stress recovery elicited by standard cognitive tasks, as assessed by change in breathing rate from cognitive tasks to recovery rest

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=40 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=46 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Recovery (Breathing Rate) for Younger Adults
Time 1
-4.134 breaths per minute
Standard Deviation 3.097
-3.555 breaths per minute
Standard Deviation 3.121
Stress Recovery (Breathing Rate) for Younger Adults
Time 2
-1.563 breaths per minute
Standard Deviation 2.533
-4.722 breaths per minute
Standard Deviation 4.070

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Difference in stress recovery elicited by standard cognitive tasks, as assessed by change in breathing rate from cognitive tasks to recovery rest

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=18 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=18 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Recovery (Breathing Rate) for Older Adults
Time 1
-3.194 breaths per minute
Standard Deviation 3.589
-3.935 breaths per minute
Standard Deviation 2.487
Stress Recovery (Breathing Rate) for Older Adults
Time 2
-3.864 breaths per minute
Standard Deviation 4.262
-4.046 breaths per minute
Standard Deviation 4.169

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Difference in stress reactivity elicited by standard cognitive tasks, as assessed by change in systolic blood pressure from rest to cognitive tasks

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=45 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=51 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Reactivity (Systolic Blood Pressure) for Younger Adults
Time 1
1.424 mmHg
Standard Deviation 8.867
3.090 mmHg
Standard Deviation 10.659
Stress Reactivity (Systolic Blood Pressure) for Younger Adults
Time 2
1.812 mmHg
Standard Deviation 7.864
-0.729 mmHg
Standard Deviation 8.402

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Difference in stress reactivity elicited by standard cognitive tasks, as assessed by change in systolic blood pressure from rest to cognitive tasks

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=23 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=23 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Reactivity (Systolic Blood Pressure) for Older Adults
Time 1
6.196 mmHg
Standard Deviation 12.727
6.303 mmHg
Standard Deviation 12.349
Stress Reactivity (Systolic Blood Pressure) for Older Adults
Time 2
0.043 mmHg
Standard Deviation 11.351
6.553 mmHg
Standard Deviation 12.311

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Difference in stress reactivity elicited by standard cognitive tasks, as assessed by change in heart rate from rest to cognitive tasks

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=29 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=32 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Reactivity (Heart Rate) for Younger Adults
Time 1
3.969 beats per minute
Standard Deviation 5.085
4.270 beats per minute
Standard Deviation 5.168
Stress Reactivity (Heart Rate) for Younger Adults
Time 2
2.951 beats per minute
Standard Deviation 4.242
2.060 beats per minute
Standard Deviation 3.776

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Difference in stress reactivity elicited by standard cognitive tasks, as assessed by change in heart rate from cognitive tasks to recovery rest

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=18 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=14 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Reactivity (Heart Rate) for Older Adults
Time 1
3.555 beats per minute
Standard Deviation 2.138
3.991 beats per minute
Standard Deviation 3.987
Stress Reactivity (Heart Rate) for Older Adults
Time 2
1.951 beats per minute
Standard Deviation 3.099
2.731 beats per minute
Standard Deviation 2.977

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Difference in stress reactivity elicited by standard cognitive tasks, as assessed by change in breathing rate from rest to cognitive tasks

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=38 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=47 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Reactivity (Breathing Rate) for Younger Adults
Time 1
3.367 breaths per minute
Standard Deviation 2.509
3.437 breaths per minute
Standard Deviation 3.096
Stress Reactivity (Breathing Rate) for Younger Adults
Time 2
2.235 breaths per minute
Standard Deviation 2.023
4.381 breaths per minute
Standard Deviation 4.082

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Difference in stress reactivity elicited by standard cognitive tasks, as assessed by change in breathing rate from rest to cognitive tasks

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=18 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=19 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Reactivity (Breathing Rate) for Older Adults
Time 1
3.975 breaths per minute
Standard Deviation 3.986
4.287 breaths per minute
Standard Deviation 2.342
Stress Reactivity (Breathing Rate) for Older Adults
Time 2
3.895 breaths per minute
Standard Deviation 3.590
3.975 breaths per minute
Standard Deviation 4.122

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Cerebral blood flow was measured at pre-training resting state and post-training paced-breathing.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=27 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=26 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Arterial Spin Labeling (ASL) for Younger Adults
Time 1
40.96 mL/100 g/min
Standard Error 1.53
44.01 mL/100 g/min
Standard Error 1.68
Arterial Spin Labeling (ASL) for Younger Adults
Time 2
38.98 mL/100 g/min
Standard Error 1.48
39.69 mL/100 g/min
Standard Error 1.61

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Cerebral blood flow was measured at pre-training resting state and post-training paced-breathing.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=17 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=13 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Arterial Spin Labeling (ASL) for Older Adults
Time 1
40.86 mL/100 g/min
Standard Error 3.04
42.06 mL/100 g/min
Standard Error 2.33
Arterial Spin Labeling (ASL) for Older Adults
Time 2
39.93 mL/100 g/min
Standard Error 1.89
30.95 mL/100 g/min
Standard Error 2.02

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

HRV measured by high frequency (HF) HRV for younger adults. HF-HRV was quantified as the spectral power of interbeat interval variability within the high frequency range (typically 0.15-0.40 Hz), which reflects parasympathetic (vagal) activity. In this study, HF-HRV was obtained using photoplethysmography (PPG) methods. During a standardized resting condition, the device continuously recorded interbeat intervals. These data were then processed via spectral analysis to calculate the power in the high frequency band. Measurements are expressed in units of milliseconds squared (ms²). Higher HF-HRV values indicate increased parasympathetic modulation and are generally associated with improved autonomic regulation and better cognitive performance.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=46 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=56 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
High Frequency (HF) HRV for Younger Adults
Time 1
6.77 log transformed power(ms^2)
Standard Deviation 0.76
6.94 log transformed power(ms^2)
Standard Deviation 1.13
High Frequency (HF) HRV for Younger Adults
Time 2
6.62 log transformed power(ms^2)
Standard Deviation 1.00
6.63 log transformed power(ms^2)
Standard Deviation 1.01

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

HRV measured by high frequency (HF) HRV for older adults. HF-HRV was quantified as the spectral power of interbeat interval variability within the high frequency range (typically 0.15-0.40 Hz), which reflects parasympathetic (vagal) activity. In this study, HF-HRV was obtained using photoplethysmography (PPG) methods. During a standardized resting condition, the device continuously recorded interbeat intervals. These data were then processed via spectral analysis to calculate the power in the high frequency band. Measurements are expressed in units of milliseconds squared (ms²). Higher HF-HRV values indicate increased parasympathetic modulation and are generally associated with improved autonomic regulation and better cognitive performance.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=28 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=25 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
High Frequency (HF) HRV for Older Adults
Time 1
5.40 log transformed power(ms^2)
Standard Deviation 1.08
5.56 log transformed power(ms^2)
Standard Deviation 0.89
High Frequency (HF) HRV for Older Adults
Time 2
5.63 log transformed power(ms^2)
Standard Deviation 1.16
5.78 log transformed power(ms^2)
Standard Deviation 1.04

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

HRV measured by low frequency (LF) HRV for younger adults. LF-HRV was quantified as the spectral power of interbeat interval variability within the low frequency range (typically 0.04-0.15 Hz), which reflects the combined influences of sympathetic and parasympathetic activity. In this study, LF-HRV was obtained using photoplethysmography (PPG) methods. During a standardized resting condition, the device continuously recorded interbeat intervals. These data were then processed via spectral analysis to calculate the power in the low frequency band. Measurements are expressed in units of milliseconds squared (ms²). Although LF-HRV reflects contributions from both branches of the autonomic nervous system, higher LF-HRV values can indicate enhanced autonomic modulation, with interpretation made in the context of overall autonomic balance.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=46 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=56 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Low Frequency (LF) HRV for Younger Adults
Time 1
6.95 log transformed power(ms^2)
Standard Deviation 0.93
7.25 log transformed power(ms^2)
Standard Deviation 1.03
Low Frequency (LF) HRV for Younger Adults
Time 2
6.75 log transformed power(ms^2)
Standard Deviation 1.01
7.61 log transformed power(ms^2)
Standard Deviation 1.21

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

HRV measured by low frequency (LF) HRV for older adults. LF-HRV was quantified as the spectral power of interbeat interval variability within the low frequency range (typically 0.04-0.15 Hz), which reflects the combined influences of sympathetic and parasympathetic activity. In this study, LF-HRV was obtained using photoplethysmography (PPG) methods. During a standardized resting condition, the device continuously recorded interbeat intervals. These data were then processed via spectral analysis to calculate the power in the low frequency band. Measurements are expressed in units of milliseconds squared (ms²). Although LF-HRV reflects contributions from both branches of the autonomic nervous system, higher LF-HRV values can indicate enhanced autonomic modulation, with interpretation made in the context of overall autonomic balance.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=28 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=25 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Low Frequency (LF) HRV for Older Adults
Time 1
5.14 log transformed power(ms^2)
Standard Deviation 1.39
5.66 log transformed power(ms^2)
Standard Deviation 1.19
Low Frequency (LF) HRV for Older Adults
Time 2
5.31 log transformed power(ms^2)
Standard Deviation 1.65
6.11 log transformed power(ms^2)
Standard Deviation 1.49

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

HRV measured by the root mean square of successive differences (RMSSD) for younger adults. RMSSD (Root Mean Square of Successive Differences) is a time-domain measure that quantifies the variability between successive interbeat intervals, primarily reflecting parasympathetic (vagal) activity. In this study, RMSSD was obtained using photoplethysmography (PPG) methods. During a standardized resting condition, the device continuously recorded interbeat intervals, and RMSSD was computed as the square root of the mean of the squared differences between consecutive interbeat intervals. Measurements are expressed in milliseconds (ms). Higher RMSSD values indicate increased parasympathetic modulation, generally associated with improved autonomic regulation and better cardiovascular and cognitive performance.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=46 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=56 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
The Root Mean Squared Successive Differences (RMSSD) HRV for Younger Adults
Time 2
61.78 millisecond
Standard Deviation 42.66
60.99 millisecond
Standard Deviation 28.36
The Root Mean Squared Successive Differences (RMSSD) HRV for Younger Adults
Time 1
56.78 millisecond
Standard Deviation 20.81
68.99 millisecond
Standard Deviation 40.74

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

HRV measured by the root mean square of successive differences (RMSSD) for older adults. RMSSD (Root Mean Square of Successive Differences) is a time-domain measure that quantifies the variability between successive interbeat intervals, primarily reflecting parasympathetic (vagal) activity. In this study, RMSSD was obtained using photoplethysmography (PPG) methods. During a standardized resting condition, the device continuously recorded interbeat intervals, and RMSSD was computed as the square root of the mean of the squared differences between consecutive interbeat intervals. Measurements are expressed in milliseconds (ms). Higher RMSSD values indicate increased parasympathetic modulation, generally associated with improved autonomic regulation and better cardiovascular and cognitive performance.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=28 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=25 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
The Root Mean Squared Successive Differences (RMSSD) HRV for Older Adults
Time 1
33.39 millisecond
Standard Deviation 15.07
33.99 millisecond
Standard Deviation 16.87
The Root Mean Squared Successive Differences (RMSSD) HRV for Older Adults
Time 2
39.09 millisecond
Standard Deviation 20.55
42.17 millisecond
Standard Deviation 26.05

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Inflammation measured by salivary C-reactive protein (CRP) for younger adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=47 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=52 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Inflammation Measured by C-reactive Protein for Younger Adults
Time 2
3985.363 CRP level (pg/ml)
Standard Error 3277.311
6093.377 CRP level (pg/ml)
Standard Error 3115.766
Inflammation Measured by C-reactive Protein for Younger Adults
Time 1
4069.873 CRP level (pg/ml)
Standard Error 4107.658
8193.259 CRP level (pg/ml)
Standard Error 3905.210

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Inflammation measured by salivary C-reactive protein (CRP) for older adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=14 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=14 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Inflammation Measured by C-reactive Protein for Older Adults
Time 1
864.984 CRP level (pg/ml)
Standard Error 1063.422
2809.771 CRP level (pg/ml)
Standard Error 1063.422
Inflammation Measured by C-reactive Protein for Older Adults
Time 2
509.761 CRP level (pg/ml)
Standard Error 437.418
1440.859 CRP level (pg/ml)
Standard Error 437.418

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Inflammation measured by salivary IL-1b levels for younger adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=46 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=53 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Inflammation Measured by IL-1b Levels for Younger Adults
Time 1
91.827 IL-1b level (pg/ml)
Standard Error 16.987
80.063 IL-1b level (pg/ml)
Standard Error 15.825
Inflammation Measured by IL-1b Levels for Younger Adults
Time 2
76.446 IL-1b level (pg/ml)
Standard Error 14.624
86.474 IL-1b level (pg/ml)
Standard Error 13.624

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Inflammation measured by salivary IL-1b levels for older adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=12 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=15 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Inflammation Measured by IL-1b Levels for Older Adults
Time 1
89.007 IL-1b level (pg/ml)
Standard Error 82.157
218.580 IL-1b level (pg/ml)
Standard Error 73.483
Inflammation Measured by IL-1b Levels for Older Adults
Time 2
90.668 IL-1b level (pg/ml)
Standard Error 50.131
174.882 IL-1b level (pg/ml)
Standard Error 44.839

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Inflammation measured by salivary IL-6 levels for younger adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=46 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=53 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Inflammation Measured by IL-6 Levels for Younger Adults
Time 1
3.571 IL-6 level (pg/ml)
Standard Error 0.921
4.653 IL-6 level (pg/ml)
Standard Error 0.858
Inflammation Measured by IL-6 Levels for Younger Adults
Time 2
3.029 IL-6 level (pg/ml)
Standard Error 0.949
4.510 IL-6 level (pg/ml)
Standard Error 0.884

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Inflammation measured by salivary IL-6 levels for older adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=12 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=15 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Inflammation Measured by IL-6 Levels for Older Adults
Time 1
7.595 IL-6 level (pg/ml)
Standard Error 4.963
10.559 IL-6 level (pg/ml)
Standard Error 4.439
Inflammation Measured by IL-6 Levels for Older Adults
Time 2
4.605 IL-6 level (pg/ml)
Standard Error 2.357
8.260 IL-6 level (pg/ml)
Standard Error 2.108

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Inflammation measured by salivary IL-8 levels for younger adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=46 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=53 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Inflammation Measured by IL-8 Levels for Younger Adults
Time 1
540.543 IL-8 level (pg/ml)
Standard Error 96.140
513.510 IL-8 level (pg/ml)
Standard Error 89.567
Inflammation Measured by IL-8 Levels for Younger Adults
Time 2
502.338 IL-8 level (pg/ml)
Standard Error 65.304
448.990 IL-8 level (pg/ml)
Standard Error 60.839

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Inflammation measured by salivary IL-8 levels for older adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=12 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=15 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Inflammation Measured by IL-8 Levels for Older Adults
Time 1
656.653 IL-8 level (pg/ml)
Standard Error 302.589
1440.907 IL-8 level (pg/ml)
Standard Error 270.644
Inflammation Measured by IL-8 Levels for Older Adults
Time 2
698.642 IL-8 level (pg/ml)
Standard Error 306.182
1343.894 IL-8 level (pg/ml)
Standard Error 273.858

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Inflammation measured by salivary TNF-a levels for younger adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=46 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=53 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Inflammation Measured by TNF-a Levels for Younger Adults
Time 1
2.947 TNF-a level (pg/ml)
Standard Error 0.394
2.792 TNF-a level (pg/ml)
Standard Error 0.367
Inflammation Measured by TNF-a Levels for Younger Adults
Time 2
2.202 TNF-a level (pg/ml)
Standard Error 0.441
3.241 TNF-a level (pg/ml)
Standard Error 0.411

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Inflammation measured by salivary TNF-a levels for older adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=12 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=15 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Inflammation Measured by TNF-a Levels for Older Adults
Time 1
1.607 TNF-a level (pg/ml)
Standard Error 1.056
4.271 TNF-a level (pg/ml)
Standard Error 0.945
Inflammation Measured by TNF-a Levels for Older Adults
Time 2
2.338 TNF-a level (pg/ml)
Standard Error 1.101
3.887 TNF-a level (pg/ml)
Standard Error 0.985

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Plasma Aβ40 levels at pre- and post-intervention were compared between HRV-increase and HRV-decrease group for younger adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=24 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=30 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Plasma Amyloid Beta 40 (Aβ40) for Younger Adults
Time 1 (pre-intervention)
151.75 pg/ml
Standard Error 4.95
166.95 pg/ml
Standard Error 7.58
Plasma Amyloid Beta 40 (Aβ40) for Younger Adults
Time 2 (post-intervention)
172.16 pg/ml
Standard Error 7.87
150.25 pg/ml
Standard Error 7.16

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Plasma Aβ40 levels at pre- and post-intervention were compared between HRV-increase and HRV-decrease group for older adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=27 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=27 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Plasma Amyloid Beta 40 (Aβ40) for Older Adults
Time 1 (pre-intervention)
211.76 pg/ml
Standard Error 23.47
198.02 pg/ml
Standard Error 9.15
Plasma Amyloid Beta 40 (Aβ40) for Older Adults
Time 2 (post-intervention)
227.99 pg/ml
Standard Error 19.85
189.95 pg/ml
Standard Error 12.76

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Plasma Aβ42 levels at pre- and post-intervention were compared between HRV-increase and HRV-decrease group for younger adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=24 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=30 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Plasma Amyloid Beta 42 (Aβ42) Younger Adults
Time 1 (pre-intervention)
9.26 pg/ml
Standard Error 0.47
9.77 pg/ml
Standard Error 0.43
Plasma Amyloid Beta 42 (Aβ42) Younger Adults
Time 2 (post-intervention)
10.84 pg/ml
Standard Error 0.74
8.85 pg/ml
Standard Error 0.46

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Plasma Aβ42 levels at pre- and post-intervention were compared between HRV-increase and HRV-decrease group for older adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=27 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=27 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Plasma Amyloid Beta 42 (Aβ42) for Older Adults
Time 1 (pre-intervention)
10.54 pg/ml
Standard Error 0.75
10.78 pg/ml
Standard Error 0.58
Plasma Amyloid Beta 42 (Aβ42) for Older Adults
Time 2 (post-intervention)
11.80 pg/ml
Standard Error 0.55
10.94 pg/ml
Standard Error 0.62

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Plasma pTau levels at pre- and post-intervention were reported for HRV-increase and HRV-decrease group for younger adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=24 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=30 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Plasma Phosphorylated Tau 181 (pTau) for Younger Adults
Time 1 (pre-intervention)
1.57 pg/ml
Standard Error 0.14
1.57 pg/ml
Standard Error 0.12
Plasma Phosphorylated Tau 181 (pTau) for Younger Adults
Time 2 (post-intervention)
1.66 pg/ml
Standard Error 0.15
1.63 pg/ml
Standard Error 0.12

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Plasma pTau levels at pre- and post-intervention were compared between HRV-increase and HRV-decrease group for older adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=27 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=27 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Plasma Phosphorylated Tau 181 (pTau) for Older Adults
Time 1 (pre-intervention)
2.94 pg/ml
Standard Error 0.36
2.55 pg/ml
Standard Error 0.22
Plasma Phosphorylated Tau 181 (pTau) for Older Adults
Time 2 (post-intervention)
2.29 pg/ml
Standard Error 0.26
2.64 pg/ml
Standard Error 0.31

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Plasma tTau levels at pre- and post-intervention were reported for HRV-increase and HRV-decrease group for younger adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=24 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=30 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Plasma Total Tau (tTau) for Younger Adults
Time 1 (pre-intervention)
2.11 pg/ml
Standard Error 0.16
2.13 pg/ml
Standard Error 0.14
Plasma Total Tau (tTau) for Younger Adults
Time 2 (post-intervention)
2.55 pg/ml
Standard Error 0.20
1.87 pg/ml
Standard Error 0.12

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Plasma tTau levels at pre- and post-intervention were compared between HRV-increase and HRV-decrease group for older adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=27 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=27 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Plasma Total Tau (tTau) for Older Adults
Time 1 (pre-intervention)
2.07 pg/ml
Standard Error 0.17
1.91 pg/ml
Standard Error 0.12
Plasma Total Tau (tTau) for Older Adults
Time 2 (post-intervention)
2.13 pg/ml
Standard Error 0.12
2.17 pg/ml
Standard Error 0.22

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

LC-innervated subregion volume in the hippocampus at pre- and post-intervention was compared between the HRV-increase and HRV-decrease groups in younger adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=47 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=49 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
LC-innervated Subregion Volume in the Hippocampus for Younger Adults
Time 2 (post-intervention)
1142.45 mm^3
Standard Error 15.33
1172.27 mm^3
Standard Error 15.01
LC-innervated Subregion Volume in the Hippocampus for Younger Adults
Time 1 (pre-intervention)
1142.29 mm^3
Standard Error 15.32
1177.99 mm^3
Standard Error 15.00

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

LC-innervated subregion volume in the hippocampus at pre- and post-intervention was compared between the HRV-increase and HRV-decrease groups in older adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=25 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=23 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
LC-innervated Subregion Volume in the Hippocampus for Older Adults
Time 1 (pre-intervention)
1126.17 mm^3
Standard Error 22.62
1095.66 mm^3
Standard Error 23.58
LC-innervated Subregion Volume in the Hippocampus for Older Adults
Time 2 (post-intervention)
1110.82 mm^3
Standard Error 22.62
1106.20 mm^3
Standard Error 24.18

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Left orbitofrontal volume at pre- and post-intervention was compared between the HRV-increase and HRV-decrease groups in younger adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=47 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=49 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Cortical Volume in the Left Orbitofrontal Cortex for Younger Adults
Time 1 (pre-intervention)
14024.90 mm^3
Standard Error 122.34
14001.81 mm^3
Standard Error 119.80
Cortical Volume in the Left Orbitofrontal Cortex for Younger Adults
Time 2 (post-intervention)
13878.29 mm^3
Standard Error 128.47
14055.29 mm^3
Standard Error 125.81

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Left orbitofrontal volume at pre- and post-intervention was compared between the HRV-increase and HRV-decrease groups in older adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=25 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=23 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Cortical Volume in the Left Orbitofrontal Cortex for Older Adults
Time 1 (pre-intervention)
12391.75 mm^3
Standard Error 143.44
12369.59 mm^3
Standard Error 146.40
Cortical Volume in the Left Orbitofrontal Cortex for Older Adults
Time 2 (post-intervention)
12290.84 mm^3
Standard Error 149.65
12452.50 mm^3
Standard Error 152.74

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Right orbitofrontal volume at pre- and post-intervention was compared between the HRV-increase and HRV-decrease groups in younger adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=47 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=49 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Cortical Volume in the Right Orbitofrontal Cortex for Younger Adults
Time 2 (post-intervention)
13898.56 mm^3
Standard Error 134.87
14233.22 mm^3
Standard Error 132.08
Cortical Volume in the Right Orbitofrontal Cortex for Younger Adults
Time 1 (pre-intervention)
14005.03 mm^3
Standard Error 134.84
14231.64 mm^3
Standard Error 132.05

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Right orbitofrontal volume at pre- and post-intervention was compared between the HRV-increase and HRV-decrease groups in older adults.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=25 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=23 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Cortical Volume in the Right Orbitofrontal Cortex for Older Adults
Time 1 (pre-intervention)
12582.37 mm^3
Standard Error 147.77
12246.75 mm^3
Standard Error 150.82
Cortical Volume in the Right Orbitofrontal Cortex for Older Adults
Time 2 (post-intervention)
12540.15 mm^3
Standard Error 154.36
12278.02 mm^3
Standard Error 157.55

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

The strength of resting-state functional connectivity between mPFC and the left amygdala was measured by correlation coefficients. The difference in functional connectivity between the two time points (Time 2 - Time 1) was calculated. Higher values indicate greater connectivity at Time 2 than Time 1 (or post- than pre-intervention).

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=47 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=49 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
mPFC-left Amygdala Resting-state Functional Connectivity for Younger Adults (Post-Pre)
-0.018 correlation coefficients
Standard Error 0.025
0.093 correlation coefficients
Standard Error 0.040

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

The strength of resting-state functional connectivity between mPFC and the left amygdala was measured by correlation coefficients. The difference in functional connectivity between the two time points (Time 2 - Time 1) was calculated. Higher values indicate greater connectivity at Time 2 than Time 1 (or post- than pre-intervention).

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=25 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=26 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
mPFC-left Amygdala Resting-state Functional Connectivity for Older Adults (Post-Pre)
0.074 correlation coefficients
Standard Error 0.051
0.002 correlation coefficients
Standard Error 0.080

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

The strength of resting-state functional connectivity was measured by correlation coefficients. Values represent the correlation of BOLD time-series between mPFC and the left amygdala. Higher values indicate greater connectivity.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=47 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=49 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
mPFC-left Amygdala Resting-state Functional Connectivity for Younger Adults (ANOVA)
Time 1
0.089 correlation coefficients
Standard Error 0.022
0.076 correlation coefficients
Standard Error 0.021
mPFC-left Amygdala Resting-state Functional Connectivity for Younger Adults (ANOVA)
Time 2
0.072 correlation coefficients
Standard Error 0.021
0.168 correlation coefficients
Standard Error 0.021

SECONDARY outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

The strength of resting-state functional connectivity was measured by correlation coefficients. Values represent the correlation of BOLD time-series between mPFC and the left amygdala. Higher values indicate greater connectivity.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=25 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=26 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
mPFC-left Amygdala Resting-state Functional Connectivity for Older Adults (ANOVA)
Time 1
0.079 correlation coefficients
Standard Error 0.051
0.200 correlation coefficients
Standard Error 0.050
mPFC-left Amygdala Resting-state Functional Connectivity for Older Adults (ANOVA)
Time 2
0.153 correlation coefficients
Standard Error 0.049
0.202 correlation coefficients
Standard Error 0.048

OTHER_PRE_SPECIFIED outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Working memory performance measured by NIH Toolbox List Sorting Working Memory Test (LSWM). The standard score is calculated to have a normative mean of 100 and a standard deviation (SD) of 15. Scores range from 59 to 140, with higher scores indicating better Working memory.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=49 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=56 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Working Memory for Younger Adults
Time 1
98.04 age corrected standard score
Standard Deviation 14.00
98.39 age corrected standard score
Standard Deviation 10.35
Working Memory for Younger Adults
Time 2
103.10 age corrected standard score
Standard Deviation 12.21
105.13 age corrected standard score
Standard Deviation 10.39

OTHER_PRE_SPECIFIED outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Working memory performance measured by NIH Toolbox List Sorting Working Memory Test (LSWM). The standard score is calculated to have a normative mean of 100 and a standard deviation (SD) of 15. Scores range from 59 to 140, with higher scores indicating better Working memory.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=28 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=31 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Working Memory for Older Adults
Time 1
101.29 age corrected standard score
Standard Deviation 14.14
102.48 age corrected standard score
Standard Deviation 14.82
Working Memory for Older Adults
Time 2
104.82 age corrected standard score
Standard Deviation 11.16
103.06 age corrected standard score
Standard Deviation 13.95

OTHER_PRE_SPECIFIED outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Processing speed performance measured by NIH Toolbox Pattern Comparison Processing Speed Test (PCPS). The standard score is calculated to have a normative mean of 100 and a standard deviation (SD) of 15. Scores range from 59 to 140, with higher scores indicating faster processing speed.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=49 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=56 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Processing Speed for Younger Adults
Time 1
105.55 age corrected standard score
Standard Deviation 18.53
102.64 age corrected standard score
Standard Deviation 22.69
Processing Speed for Younger Adults
Time 2
118.51 age corrected standard score
Standard Deviation 16.08
116.30 age corrected standard score
Standard Deviation 17.72

OTHER_PRE_SPECIFIED outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Processing speed performance measured by NIH Toolbox Pattern Comparison Processing Speed Test (PCPS). The standard score is calculated to have a normative mean of 100 and a standard deviation (SD) of 15. Scores range from 59 to 140, with higher scores indicating faster processing speed.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=28 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=31 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Processing Speed for Older Adults
Time 1
98.54 age corrected standard score
Standard Deviation 20.96
106.55 age corrected standard score
Standard Deviation 21.10
Processing Speed for Older Adults
Time 2
105.43 age corrected standard score
Standard Deviation 17.57
107.68 age corrected standard score
Standard Deviation 25.53

OTHER_PRE_SPECIFIED outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Inhibitory control performance measured by NIH Toolbox Flanker Inhibitory Control and Attention Test (Flanker). The standard score is calculated to have a normative mean of 100 and a standard deviation (SD) of 15. Scores range from 59 to 140, with higher scores indicating better Inhibitory Control and Attention.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=49 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=56 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Inhibitory Control and Attention for Younger Adults
Time 1
84.90 age corrected standard score
Standard Deviation 12.17
87.27 age corrected standard score
Standard Deviation 14.29
Inhibitory Control and Attention for Younger Adults
Time 2
88.71 age corrected standard score
Standard Deviation 11.96
89.21 age corrected standard score
Standard Deviation 15.03

OTHER_PRE_SPECIFIED outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Inhibitory control performance measured by NIH Toolbox Flanker Inhibitory Control and Attention Test (Flanker). The standard score is calculated to have a normative mean of 100 and a standard deviation (SD) of 15. Scores range from 59 to 140, with higher scores indicating better Inhibitory Control and Attention.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=28 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=31 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Inhibitory Control and Attention for Older Adults
Time 1
89.82 age corrected standard score
Standard Deviation 11.17
90.84 age corrected standard score
Standard Deviation 8.91
Inhibitory Control and Attention for Older Adults
Time 2
92.04 age corrected standard score
Standard Deviation 13.44
93.29 age corrected standard score
Standard Deviation 8.76

OTHER_PRE_SPECIFIED outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Sustained attention performance was measured by Sustained Attention to Response Test (SART). A commission error was calculated as the number of button press for 25 no-go trials, and an omission error was calculated as the number of no button press for 200 go trials in younger adults. The number of errors range from 0 to 25 for commission errors and from 0 to 200 for omission errors. A higher number of omission and commission errors indicates worse sustained attention performance.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=47 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=53 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Sustained Attention for Younger Adults
Time 1: commission error
12.979 number of errors
Standard Error 0.994
12.679 number of errors
Standard Error 0.936
Sustained Attention for Younger Adults
Time 2: commission error
9.851 number of errors
Standard Error 1.106
9.830 number of errors
Standard Error 1.041
Sustained Attention for Younger Adults
Time 1: omission error
3.383 number of errors
Standard Error 0.628
1.906 number of errors
Standard Error 0.592
Sustained Attention for Younger Adults
Time 2: omission error
2.383 number of errors
Standard Error 0.574
1.792 number of errors
Standard Error 0.541

OTHER_PRE_SPECIFIED outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Sustained attention performance was measured by Sustained Attention to Response Test (SART). A commission error was calculated as the number of button press for 25 no-go trials, and an omission error was calculated as the number of no button press for 200 go trials in older adults. The number of errors range from 0 to 25 for commission errors and from 0 to 200 for omission errors. A higher number of omission and commission errors indicates worse sustained attention performance.

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=19 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=26 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Sustained Attention for Older Adults
Time 1: commission error
9.211 number of errors
Standard Error 1.371
9.538 number of errors
Standard Error 1.172
Sustained Attention for Older Adults
Time 2: commission error
8.789 number of errors
Standard Error 1.347
8.692 number of errors
Standard Error 1.152
Sustained Attention for Older Adults
Time 1: omission error
4.947 number of errors
Standard Error 1.389
3.731 number of errors
Standard Error 1.187
Sustained Attention for Older Adults
Time 2: omission error
2.842 number of errors
Standard Error 0.894
1.731 number of errors
Standard Error 0.765

OTHER_PRE_SPECIFIED outcome

Timeframe: Week 5 Lab Visit (after about 2.5-3 weeks of training)

Population: Population analyzed was composed by all randomization subjects who completed the memory tests and whose data quality was sufficient for data analysis.

Recognition memory performance based on average proportion of previously presented images that were correctly identified (i.e., hits) by younger adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=50 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=55 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Recognition Memory for Younger Adults (Hits)
Positive
.866 Proportion of correct hits
Standard Error .011
.886 Proportion of correct hits
Standard Error .012
Recognition Memory for Younger Adults (Hits)
Negative
.900 Proportion of correct hits
Standard Error .012
.914 Proportion of correct hits
Standard Error .011
Recognition Memory for Younger Adults (Hits)
Neutral
.873 Proportion of correct hits
Standard Error .013
.880 Proportion of correct hits
Standard Error .014

OTHER_PRE_SPECIFIED outcome

Timeframe: Week 5 Lab Visit (after about 2.5-3 weeks of training)

Population: Population analyzed was composed by all randomization subjects who completed the memory tests and whose data quality was sufficient for data analysis.

Recognition memory performance based on average proportion of previously presented images that were correctly identified (i.e., hits) by older adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=31 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=29 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Recognition Memory for Older Adults (Hits)
Neutral
.859 Proportion of correct hits
Standard Error .015
.828 Proportion of correct hits
Standard Error .020
Recognition Memory for Older Adults (Hits)
Positive
.851 Proportion of correct hits
Standard Error .016
.820 Proportion of correct hits
Standard Error .022
Recognition Memory for Older Adults (Hits)
Negative
.870 Proportion of correct hits
Standard Error .014
.875 Proportion of correct hits
Standard Error .017

OTHER_PRE_SPECIFIED outcome

Timeframe: Week 5 Lab Visit (after about 2.5-3 weeks of training)

Population: Population analyzed was composed by all randomization subjects who completed the memory tests and whose data quality was sufficient for data analysis.

Recognition memory performance based on average proportion of images not previously presented that were incorrectly identified as seen (i.e., False Alarms) by younger adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=50 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=55 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Recognition Memory for Younger Adults (False Alarm)
Neutral
.042 Proportion of false alarm
Standard Error .006
.048 Proportion of false alarm
Standard Error .007
Recognition Memory for Younger Adults (False Alarm)
Positive
.046 Proportion of false alarm
Standard Error .008
.044 Proportion of false alarm
Standard Error .008
Recognition Memory for Younger Adults (False Alarm)
Negative
.041 Proportion of false alarm
Standard Error .007
.027 Proportion of false alarm
Standard Error .005

OTHER_PRE_SPECIFIED outcome

Timeframe: Week 5 Lab Visit (after about 2.5-3 weeks of training)

Population: Population analyzed was composed by all randomization subjects who completed the memory tests and whose data quality was sufficient for data analysis.

Recognition memory performance based on average proportion of images not previously presented that were incorrectly identified as seen (i.e., False Alarms) by older adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=31 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=29 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Recognition Memory for Older Adults (False Alarm)
Neutral
.047 Proportion of false alarms
Standard Error .011
.091 Proportion of false alarms
Standard Error .017
Recognition Memory for Older Adults (False Alarm)
Positive
.062 Proportion of false alarms
Standard Error .011
.093 Proportion of false alarms
Standard Error .018
Recognition Memory for Older Adults (False Alarm)
Negative
.052 Proportion of false alarms
Standard Error .011
.069 Proportion of false alarms
Standard Error .012

OTHER_PRE_SPECIFIED outcome

Timeframe: Week 5 Lab Visit (after about 2.5-3 weeks of training)

Population: Population analyzed was composed by all randomization subjects who completed the memory tests and whose data quality was sufficient for data analysis.

Average proportion of previously presented images that were correctly recalled by younger adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=50 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=52 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Recall Memory for Younger Adults
Positive
.214 Proportion of items correctly recalled
Standard Error .023
.285 Proportion of items correctly recalled
Standard Error .023
Recall Memory for Younger Adults
Negative
.262 Proportion of items correctly recalled
Standard Error .027
.248 Proportion of items correctly recalled
Standard Error .020

OTHER_PRE_SPECIFIED outcome

Timeframe: Week 5 Lab Visit (after about 2.5-3 weeks of training)

Population: Population analyzed was composed by all randomization subjects who completed the memory tests and whose data quality was sufficient for data analysis.

Average proportion of previously presented images that were correctly recalled by older adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=28 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=27 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Recall Memory for Older Adults
Positive
.156 Proportion of items correctly recalled
Standard Error .025
.203 Proportion of items correctly recalled
Standard Error .030
Recall Memory for Older Adults
Negative
.286 Proportion of items correctly recalled
Standard Error .040
.225 Proportion of items correctly recalled
Standard Error .036

OTHER_PRE_SPECIFIED outcome

Timeframe: Time 1 (Baseline), Time 2 (5 weeks)

Population: Population analyzed was composed by all randomization subjects who completed pre- and post-intervention assessments and whose data quality was sufficient for data analysis.

Stress measured by salivary cortisol levels for younger adults

Outcome measures

Outcome measures
Measure
Younger HRV-decrease Group
n=44 Participants
Participants in this group were between the ages of 18 and 35. Half of the younger participants were randomly assigned to this group and underwent daily practice to decrease their heart rate variability (HRV) for 5 weeks.
Older HRV-increase Group
n=50 Participants
Participants in this group were between the ages of 55 and 80. Half of the older participants were randomly assigned to this group and underwent daily practice to increase their heart rate variability (HRV) for 5 weeks.
Stress Measured by Cortisol Levels for Younger Adults
Time 1: cortisol level at awakening
0.248 CAR level (µg/dL)
Standard Error 0.024
0.231 CAR level (µg/dL)
Standard Error 0.023
Stress Measured by Cortisol Levels for Younger Adults
Time 1: cortisol level at 30 min after awakening
0.453 CAR level (µg/dL)
Standard Error 0.037
0.431 CAR level (µg/dL)
Standard Error 0.035
Stress Measured by Cortisol Levels for Younger Adults
Time 2: cortisol level at awakening
0.309 CAR level (µg/dL)
Standard Error 0.035
0.284 CAR level (µg/dL)
Standard Error 0.033
Stress Measured by Cortisol Levels for Younger Adults
Time 2: cortisol level at 30 min after awakening
0.472 CAR level (µg/dL)
Standard Error 0.048
0.478 CAR level (µg/dL)
Standard Error 0.045

Adverse Events

Younger HRV-increase Group

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Younger HRV-decrease Group

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Older HRV-increase Group

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Older HRV-decrease Group

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Mara Mather

University of Southern California

Phone: (213) 821-1868

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place