Trial Outcomes & Findings for Reducing Particulate Matter-associated Cardiovascular Health Effects for Seniors (NCT NCT04103346)

NCT ID: NCT04103346

Last Updated: 2026-01-16

Results Overview

Systolic blood pressure was measured twice a day, in the morning and the evening, from Tuesday through Friday during the first and fourth week of each of the four-week periods in which participants were exposed to one of the interventions. Results reflect the average of systolic readings taken.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

52 participants

Primary outcome timeframe

10 weeks

Results posted on

2026-01-16

Participant Flow

17 participants withdrew from the trial prior to randomization. Of the 35 participants who were randomized, data from 2 was not included in the analyses, because of external factors that rendered the data from those participants unusable.

Participant milestones

Participant milestones
Measure
Air Filtration With Hepa Filter, Then With Hepa Filter Removed
air purifier used is the Holmes HAP8650B-NU-1 with the hepa filter inserted, then with the filter removed following washout (sham comparator). air filtration with air purifier with hepa filter: long-term (4 week) air filtration with the Holmes HAP8650B-NU-1 air purifier in the residence of low-income seniors impacted by roadway pollutants. sham: air purifier running with air filter removed
Air Filtration Without Hepa Filter, Then With Hepa Filter
sham comparator used the Holmes HAP8650B-NU-1 air purifier to be operated without the filter, then with the hepa filter installed following washout. air filtration with air purifier with hepa filter: long-term (4 week) air filtration with the Holmes HAP8650B-NU-1 air purifier in the residence of low-income seniors impacted by roadway pollutants. sham: air purifier running with air filter removed
Phase 1 - 4 Weeks
STARTED
21
12
Phase 1 - 4 Weeks
COMPLETED
21
12
Phase 1 - 4 Weeks
NOT COMPLETED
0
0
Washout - 2 Weeks
STARTED
21
12
Washout - 2 Weeks
COMPLETED
21
12
Washout - 2 Weeks
NOT COMPLETED
0
0
Phase II - 4 Weeks
STARTED
21
12
Phase II - 4 Weeks
COMPLETED
21
12
Phase II - 4 Weeks
NOT COMPLETED
0
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Reducing Particulate Matter-associated Cardiovascular Health Effects for Seniors

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Air Filtration With Hepa Filter, Then With Hepa Filter Removed
n=21 Participants
air purifier used is the Holmes HAP8650B-NU-1 with the hepa filter inserted, then with the filter removed following washout (sham comparator). air filtration with air purifier with hepa filter: long-term (4 week) air filtration with the Holmes HAP8650B-NU-1 air purifier in the residence of low-income seniors impacted by roadway pollutants. sham: air purifier running with air filter removed
Air Filtration Without Hepa Filter, Then With Hepa Filter
n=12 Participants
sham comparator used the Holmes HAP8650B-NU-1 air purifier to be operated without the filter, then with the hepa filter installed following washout. air filtration with air purifier with hepa filter: long-term (4 week) air filtration with the Holmes HAP8650B-NU-1 air purifier in the residence of low-income seniors impacted by roadway pollutants. sham: air purifier running with air filter removed
Total
n=33 Participants
Total of all reporting groups
History of coronary artery disease
No
15 Participants
n=9 Participants
8 Participants
n=6 Participants
23 Participants
n=9 Participants
Age, Continuous
76.2 years
STANDARD_DEVIATION 7.11 • n=9 Participants
72.5 years
STANDARD_DEVIATION 8.12 • n=6 Participants
74.9 years
STANDARD_DEVIATION 7.59 • n=9 Participants
Sex: Female, Male
Female
15 Participants
n=9 Participants
7 Participants
n=6 Participants
22 Participants
n=9 Participants
Sex: Female, Male
Male
6 Participants
n=9 Participants
5 Participants
n=6 Participants
11 Participants
n=9 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants
n=9 Participants
0 Participants
n=6 Participants
0 Participants
n=9 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
0 Participants
n=9 Participants
0 Participants
n=6 Participants
0 Participants
n=9 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
21 Participants
n=9 Participants
12 Participants
n=6 Participants
33 Participants
n=9 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=9 Participants
0 Participants
n=6 Participants
0 Participants
n=9 Participants
Race (NIH/OMB)
Asian
5 Participants
n=9 Participants
1 Participants
n=6 Participants
6 Participants
n=9 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=9 Participants
0 Participants
n=6 Participants
0 Participants
n=9 Participants
Race (NIH/OMB)
Black or African American
2 Participants
n=9 Participants
3 Participants
n=6 Participants
5 Participants
n=9 Participants
Race (NIH/OMB)
White
14 Participants
n=9 Participants
8 Participants
n=6 Participants
22 Participants
n=9 Participants
Race (NIH/OMB)
More than one race
0 Participants
n=9 Participants
0 Participants
n=6 Participants
0 Participants
n=9 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
n=9 Participants
0 Participants
n=6 Participants
0 Participants
n=9 Participants
Region of Enrollment
United States
21 Participants
n=9 Participants
12 Participants
n=6 Participants
33 Participants
n=9 Participants
Body Mass Index (BMI)
28.7 kg/m2
STANDARD_DEVIATION 6.21 • n=9 Participants
30.2 kg/m2
STANDARD_DEVIATION 8.41 • n=6 Participants
29.2 kg/m2
STANDARD_DEVIATION 6.99 • n=9 Participants
History of coronary artery disease
Yes
6 Participants
n=9 Participants
4 Participants
n=6 Participants
10 Participants
n=9 Participants
History of cerebrovascular disease
No
20 Participants
n=9 Participants
9 Participants
n=6 Participants
29 Participants
n=9 Participants
History of cerebrovascular disease
Yes
1 Participants
n=9 Participants
3 Participants
n=6 Participants
4 Participants
n=9 Participants
History of hyperlipidemia
No
9 Participants
n=9 Participants
9 Participants
n=6 Participants
18 Participants
n=9 Participants
History of hyperlipidemia
Yes
12 Participants
n=9 Participants
3 Participants
n=6 Participants
15 Participants
n=9 Participants
History of hypertension
No
6 Participants
n=9 Participants
3 Participants
n=6 Participants
9 Participants
n=9 Participants
History of hypertension
Yes
15 Participants
n=9 Participants
9 Participants
n=6 Participants
24 Participants
n=9 Participants
History of diabetes
No
12 Participants
n=9 Participants
10 Participants
n=6 Participants
22 Participants
n=9 Participants
History of diabetes
Yes
9 Participants
n=9 Participants
2 Participants
n=6 Participants
11 Participants
n=9 Participants
Blood Pressure Medication
No
6 Participants
n=9 Participants
3 Participants
n=6 Participants
9 Participants
n=9 Participants
Blood Pressure Medication
Yes
15 Participants
n=9 Participants
9 Participants
n=6 Participants
24 Participants
n=9 Participants
Statin
No
9 Participants
n=9 Participants
9 Participants
n=6 Participants
18 Participants
n=9 Participants
Statin
Yes
12 Participants
n=9 Participants
3 Participants
n=6 Participants
15 Participants
n=9 Participants
Diabetes medication
No
12 Participants
n=9 Participants
10 Participants
n=6 Participants
22 Participants
n=9 Participants
Diabetes medication
Yes
9 Participants
n=9 Participants
2 Participants
n=6 Participants
11 Participants
n=9 Participants
Aspirin
No
14 Participants
n=9 Participants
8 Participants
n=6 Participants
22 Participants
n=9 Participants
Aspirin
Yes
7 Participants
n=9 Participants
4 Participants
n=6 Participants
11 Participants
n=9 Participants

PRIMARY outcome

Timeframe: 10 weeks

Systolic blood pressure was measured twice a day, in the morning and the evening, from Tuesday through Friday during the first and fourth week of each of the four-week periods in which participants were exposed to one of the interventions. Results reflect the average of systolic readings taken.

Outcome measures

Outcome measures
Measure
Air Filtration With Hepa Filter Removed
n=33 Participants
sham comparator uses the Holmes HAP8650B-NU-1 air purifier to be operated with the filter removed. sham: air purifier running with air filter removed
Air Filtration With Hepa Filter
n=33 Participants
air purifier used is the Holmes HAP8650B-NU-1 with the hepa filter inserted. air filtration with air purifier with hepa filter: long-term (4 week) air filtration with the Holmes HAP8650B-NU-1 air purifier in the residence of low-income seniors impacted by roadway pollutants.
Systolic Blood Pressure
126.5 mm Hg
Standard Deviation 16.0
127.0 mm Hg
Standard Deviation 16.2

SECONDARY outcome

Timeframe: 10 weeks

Diastolic blood pressure was measured twice a day, in the morning and the evening, from Tuesday through Friday during the first and fourth week of each of the four-week periods in which participants were exposed to one of the interventions. Results reflect the average of diastolic readings taken.

Outcome measures

Outcome measures
Measure
Air Filtration With Hepa Filter Removed
n=33 Participants
sham comparator uses the Holmes HAP8650B-NU-1 air purifier to be operated with the filter removed. sham: air purifier running with air filter removed
Air Filtration With Hepa Filter
n=33 Participants
air purifier used is the Holmes HAP8650B-NU-1 with the hepa filter inserted. air filtration with air purifier with hepa filter: long-term (4 week) air filtration with the Holmes HAP8650B-NU-1 air purifier in the residence of low-income seniors impacted by roadway pollutants.
Diastolic Blood Pressure
75.3 mm Hg
Standard Deviation 10.4
75.1 mm Hg
Standard Deviation 10.6

SECONDARY outcome

Timeframe: 10 weeks

Atmospheric particulate matter was measured daily in the units of ug/m3 and determined using a portable analyzer (PDR-1500). Results reflect the average amount of atmospheric particulate matter present per day.

Outcome measures

Outcome measures
Measure
Air Filtration With Hepa Filter Removed
n=33 Participants
sham comparator uses the Holmes HAP8650B-NU-1 air purifier to be operated with the filter removed. sham: air purifier running with air filter removed
Air Filtration With Hepa Filter
n=33 Participants
air purifier used is the Holmes HAP8650B-NU-1 with the hepa filter inserted. air filtration with air purifier with hepa filter: long-term (4 week) air filtration with the Holmes HAP8650B-NU-1 air purifier in the residence of low-income seniors impacted by roadway pollutants.
Atmospheric Particulate Matter (pm2.5) - Indoor
8.3 (µg/m3) per day
Standard Deviation 12.8
1.3 (µg/m3) per day
Standard Deviation 1.5

SECONDARY outcome

Timeframe: 10 weeks

Atmospheric particulate matter was measured daily in units of ug/m3 and determined using a portable analyzer (PDR-1500). Results reflect the average amount of atmospheric particulate matter present per day.

Outcome measures

Outcome measures
Measure
Air Filtration With Hepa Filter Removed
n=33 Participants
sham comparator uses the Holmes HAP8650B-NU-1 air purifier to be operated with the filter removed. sham: air purifier running with air filter removed
Air Filtration With Hepa Filter
n=33 Participants
air purifier used is the Holmes HAP8650B-NU-1 with the hepa filter inserted. air filtration with air purifier with hepa filter: long-term (4 week) air filtration with the Holmes HAP8650B-NU-1 air purifier in the residence of low-income seniors impacted by roadway pollutants.
Atmospheric Particulate Matter (pm2.5) - Outdoor
8.9 (µg/m3) per day
Standard Deviation 2.3
10.3 (µg/m3) per day
Standard Deviation 5.8

SECONDARY outcome

Timeframe: 2 days

PM2.5 mass measured from the filters contained in the personal particulate monitors worn for 24-hours by participants performed on the last week of each cross-over limb (twice per participant in total). 24-hour data collection for personal PM2.5 exposure was collected from Thursday morning at 9 am to Friday morning at 9 am during trial week 4 and during trial week 10.

Outcome measures

Outcome measures
Measure
Air Filtration With Hepa Filter Removed
n=33 Participants
sham comparator uses the Holmes HAP8650B-NU-1 air purifier to be operated with the filter removed. sham: air purifier running with air filter removed
Air Filtration With Hepa Filter
n=33 Participants
air purifier used is the Holmes HAP8650B-NU-1 with the hepa filter inserted. air filtration with air purifier with hepa filter: long-term (4 week) air filtration with the Holmes HAP8650B-NU-1 air purifier in the residence of low-income seniors impacted by roadway pollutants.
24-hr Personal PM2.5 (Filter-gravimetric Mass)
12.4 µg/m3 per 24-hour period
Standard Deviation 15.6
5.1 µg/m3 per 24-hour period
Standard Deviation 4.6

SECONDARY outcome

Timeframe: 10 weeks

Population: This outcome was not performed because of COVID-19 restrictions in place during the trial, and no data for this outcome will be collected.

Evaluation of the effect of active vs sham filtration on lowering black carbon levels and hourly levels of PM2.5 throughout a 24-hour period.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: 10 weeks

Population: This outcome was not performed because of COVID-19 restrictions in place during the trial, and no data for this outcome will be collected.

Determined using pulse wave analyses of the augmentation index calculated as the height of the reflected wave as a percentage of the total height of the ascending aortic pressure wave.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: 10 weeks

Population: This outcome was not performed because of COVID-19 restrictions in place during the trial, and no data for this outcome will be collected.

To determine the impact of reduced particulate matter on insulin sensitivity, determined by measuring insulin and glucose to calculate the homeostasis model assessment of insulin resistance (HOMA-IR) metric.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: 10 weeks

Population: This outcome was not performed because of COVID-19 restrictions in place during the trial, and no data for this outcome will be collected.

Panel of hair, saliva, blood

Outcome measures

Outcome data not reported

Adverse Events

Air Filtration With Hepa Filter

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

Air Filtration Without Hepa Filter

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

Geoff Barnes

University of Michigan

Phone: 734-763-0047

Results disclosure agreements

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