Trial Outcomes & Findings for Enhancing Skeletal Adaptations to PTH and Exercise (NCT NCT05029128)

NCT ID: NCT05029128

Last Updated: 2026-04-06

Results Overview

CTX is a marker of bone resorption. An increase in CTX in response to exercise is evidence of an acute catabolic response of bone.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

18 participants

Primary outcome timeframe

The primary outcome for Aim 1 is the change in CTX from immediately before exercise to 60 minutes after exercise during the 1st, 8th, and 16th exercise bout. Results are for each exercise bout and for the average of all the bouts combined.

Results posted on

2026-04-06

Participant Flow

Participants completed an initial in-person screening visit to assess whether inclusion/exclusion criteria were met. Participants were considered "enrolled" once the consent form was signed.

Screening assessments occurred between consent/enrollment and the start of data collection. Of the 18 who signed the consent, 8 passed the screening assessments. All 8 participants who passed screening started the study and 6 completed the study. There is no randomization to a study arm so all participants completed the same exercise intervention (4 weeks of treadmill exercise).

Participant milestones

Participant milestones
Measure
Aerobic Exercise
All participants engaged in treadmill exercise training
Screening Eligibility Determination
STARTED
18
Screening Eligibility Determination
COMPLETED
8
Screening Eligibility Determination
NOT COMPLETED
10
Exercise Collection
STARTED
8
Exercise Collection
COMPLETED
6
Exercise Collection
NOT COMPLETED
2

Reasons for withdrawal

Reasons for withdrawal
Measure
Aerobic Exercise
All participants engaged in treadmill exercise training
Screening Eligibility Determination
Physician Decision
10
Exercise Collection
Withdrawal by Subject
2

Baseline Characteristics

Enhancing Skeletal Adaptations to PTH and Exercise

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Aerobic Exercise
n=8 Participants
All participants engaged in 4 weeks of treadmill exercise training.
Age, Continuous
54.2 Years
STANDARD_DEVIATION 21.4 • n=5 Participants
Sex: Female, Male
Female
1 Participants
n=5 Participants
Sex: Female, Male
Male
7 Participants
n=5 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=5 Participants
Race (NIH/OMB)
Asian
0 Participants
n=5 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=5 Participants
Race (NIH/OMB)
Black or African American
0 Participants
n=5 Participants
Race (NIH/OMB)
White
7 Participants
n=5 Participants
Race (NIH/OMB)
More than one race
1 Participants
n=5 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
n=5 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
2 Participants
n=5 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
6 Participants
n=5 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
n=5 Participants
Baseline CTX
0.27 ng/mL
STANDARD_DEVIATION 0.16 • n=5 Participants

PRIMARY outcome

Timeframe: The primary outcome for Aim 1 is the change in CTX from immediately before exercise to 60 minutes after exercise during the 1st, 8th, and 16th exercise bout. Results are for each exercise bout and for the average of all the bouts combined.

Population: CTX was only analyzed for those who completed the study (N=6).

CTX is a marker of bone resorption. An increase in CTX in response to exercise is evidence of an acute catabolic response of bone.

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=6 Participants
All participants engaged in treadmill exercise training
Change in C-terminal Peptide of Type 1 Collagen (CTX)
1st Exercise Bout
0.03 ng/mL
Standard Deviation 0.02
Change in C-terminal Peptide of Type 1 Collagen (CTX)
8th Exercise Bout
0.03 ng/mL
Standard Deviation 0.04
Change in C-terminal Peptide of Type 1 Collagen (CTX)
16th Exercise Bout
0.05 ng/mL
Standard Deviation 0.06
Change in C-terminal Peptide of Type 1 Collagen (CTX)
Overall
0.03 ng/mL
Standard Deviation 0.08

PRIMARY outcome

Timeframe: The primary outcome for Aim 2 is the change in the pre-exercise P1NP (15 minutes before exercise) between the 1st and the 16th exercise bout (comparison of 2 time points).

Population: Results were only analyzed for those who completed the study (N=6).

P1NP is a marker of bone formation. An increase in P1NP from before to after an exercise intervention is evidence of an anabolic response of bone.

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=6 Participants
All participants engaged in treadmill exercise training
Change in Procollagen 1 Intact N-terminal Propeptide (P1NP)
-7.5 ng/mL
Standard Deviation 15.7

SECONDARY outcome

Timeframe: Change in serum P1NP is measured from before to immediately after the 60 minutes of exercise during the 1st, 8th, and 16th exercise bout. The average change across all exercise bouts is also included.

Population: Analysis on conducted for those who finished the study (N=6).

Serum P1NP is measured to determine if there is an acute anabolic response of bone to exercise and whether it changes in response to exercise training

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=6 Participants
All participants engaged in treadmill exercise training
Change in P1NP During Exercise
1st Exercise Bout
0.0 ng/mL
Standard Deviation 12.0
Change in P1NP During Exercise
8th Exercise Bout
9.3 ng/mL
Standard Deviation 14.0
Change in P1NP During Exercise
16th Exercise Bout
7.2 ng/mL
Standard Deviation 7.7
Change in P1NP During Exercise
Overall Change
5.4 ng/mL
Standard Deviation 11.8

SECONDARY outcome

Timeframe: Urinary Ca excretion is measured over the 4 hours of recovery after exercise. Results are presented for the 1st, 8th, and 16th exercise bout individually and for the average excretion across all 3 collections.

Population: Analysis only conducted for those who completed the study (N=6)

Urinary tCa is used to account for Ca loss subsequent to the activation of bone resorption during exercise

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=6 Participants
All participants engaged in treadmill exercise training
Urinary Calcium Excretion (uCa)
Overall
27.5 mg
Standard Deviation 32.8
Urinary Calcium Excretion (uCa)
1st Exercise Bout
37.9 mg
Standard Deviation 57.4
Urinary Calcium Excretion (uCa)
8th Exercise Bout
21.5 mg
Standard Deviation 12.9
Urinary Calcium Excretion (uCa)
16th Exercise Bout
22.5 mg
Standard Deviation 19.4

SECONDARY outcome

Timeframe: Serum iCa is measured before and 15 minutes after the 60 minutes of exercise during the 1st, 8th, and 16th exercise bout. Average change across all three exercise collection bouts is also provided.

Population: Analysis only completed for those who completed data collection (N=6).

Serum iCa is measured to assess the stimulus for PTH secretion and to describe the pattern of change in iCa during and after exercise

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=6 Participants
All participants engaged in treadmill exercise training
Change in Serum Ionized Ca (iCa)
16th Exercise Bout
-0.18 mg/dL
Standard Deviation 0.07
Change in Serum Ionized Ca (iCa)
Overall
-0.20 mg/dL
Standard Deviation 0.12
Change in Serum Ionized Ca (iCa)
1st Exercise Bout
-0.21 mg/dL
Standard Deviation 0.13
Change in Serum Ionized Ca (iCa)
8th Exercise Bout
-0.22 mg/dL
Standard Deviation 0.14

SECONDARY outcome

Timeframe: Change in serum tCa is measured before and 15 minutes after the 60 minute exercise bout during the 1st, 8th, and 16th exercise bouts. Average change across all 3 collection bouts is also included.

Population: Analysis only performed for those who completed data collection (N=6).

Serum tCa is measured to help interpret changes in iCa (e.g., changes in Ca binding) and to describe the pattern of change in tCa during and after exercise

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=6 Participants
All participants engaged in treadmill exercise training
Change in Serum Total Ca (tCa)
1st Exercise Bout
0.01 mg/dL
Standard Deviation 0.33
Change in Serum Total Ca (tCa)
8th Exercise Bout
0.10 mg/dL
Standard Deviation 0.20
Change in Serum Total Ca (tCa)
16th Exercise Bout
-0.02 mg/dL
Standard Deviation 0.29
Change in Serum Total Ca (tCa)
Overall
0.03 mg/dL
Standard Deviation 0.27

SECONDARY outcome

Timeframe: Serum PTH is measured before and 15 minutes after the 60 minute exercise bout. Results are presented for the 1st, 8th, and 16th exercise bouts individually and for the average change across all 3 collection bouts.

Population: Analysis only conducted for those who completed the study (N=6).

Serum PTH is measured to assess the stimulus for the activation of bone resorption and to describe the pattern of change in PTH during and after exercise

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=6 Participants
All participants engaged in treadmill exercise training
Change in Serum Parathyroid Hormone (PTH)
1st Exercise Bout
15.4 pg/mL
Standard Deviation 14.4
Change in Serum Parathyroid Hormone (PTH)
8th Exercise Bout
16.1 pg/mL
Standard Deviation 25.7
Change in Serum Parathyroid Hormone (PTH)
16th Exercise Bout
14.0 pg/mL
Standard Deviation 6.5
Change in Serum Parathyroid Hormone (PTH)
Overall
15.2 pg/mL
Standard Deviation 16.8

SECONDARY outcome

Timeframe: Serum PO4 is measured before and 15 minutes after the end of the 60 minute exercise bout at the 1st, 8th, and 16th exercise bout. Overall change across all 3 visits is also reported.

Population: Analysis only completed for those who finished data collection (N=6).

Serum PO4 is measured because it is a potential stimulus for PTH secretion

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=6 Participants
All participants engaged in treadmill exercise training
Change in Serum Phosphorus (PO4)
1st Exercise Bout
0.19 mg/dL
Standard Deviation 0.39
Change in Serum Phosphorus (PO4)
8th Exercise Bout
0.23 mg/dL
Standard Deviation 0.40
Change in Serum Phosphorus (PO4)
16th Exercise Bout
0.10 mg/dL
Standard Deviation 0.29
Change in Serum Phosphorus (PO4)
Overall
0.18 mg/dL
Standard Deviation 0.35

SECONDARY outcome

Timeframe: Hct is measured before and 15 minutes after the 60 minutes of exercise to correct for plasma volume shifts at the 1st, 8th, and 16th exercise bout. Average change across all 3 exercise bouts is also provided.

Population: Analysis only completed for those who completed data collection (N=6)

Hct is used to adjust iCa, tCa, PTH, CTX, P1NP, and PO4 for the plasma volume contraction that occurs with exercise

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=6 Participants
All participants engaged in treadmill exercise training
Change in Hematocrit (Hct)
1st Exercise Bout
-0.38 Percent
Standard Deviation 1.69
Change in Hematocrit (Hct)
8th Exercise Bout
0.57 Percent
Standard Deviation 1.27
Change in Hematocrit (Hct)
16th Exercise Bout
-0.33 Percent
Standard Deviation 1.63
Change in Hematocrit (Hct)
Overall
-0.05 Percent
Standard Deviation 1.53

SECONDARY outcome

Timeframe: Hgb is measured before and 15 minutes after 60 minutes of exercise to correct for plasma volume shifts. Results are presented for the 1st, 8th, and 16th exercise bouts individually and the average across all 3 exercise collection bouts.

Population: Analysis only completed for those who finished data collection (N=6).

Hgb is used to adjust iCa, tCa, PTH, CTX, P1NP, and PO4 for the plasma volume contraction that occurs with exercise

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=6 Participants
All participants engaged in treadmill exercise training
Change in Hemoglobin (Hgb)
1st Exercise Bout
-0.18 g/dL
Standard Deviation 0.87
Change in Hemoglobin (Hgb)
8th Exercise Bout
0.23 g/dL
Standard Deviation 0.38
Change in Hemoglobin (Hgb)
16th Exercise Bout
0.15 g/dL
Standard Deviation 0.36
Change in Hemoglobin (Hgb)
Overall
0.05 g/dL
Standard Deviation 0.61

OTHER_PRE_SPECIFIED outcome

Timeframe: HRmax is measured at only at baseline during the screening maximal treadmill test

Population: Analysis only performed for those who proceeded to data collection (N=8).

HRmax is used to describe the cohort and generate individual exercise prescriptions for the intervention

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=8 Participants
All participants engaged in treadmill exercise training
Maximal Heart Rate (HRmax)
170 bpm
Standard Deviation 23

OTHER_PRE_SPECIFIED outcome

Timeframe: VO2peak is only measured at baseline during the screening maximal treadmill test as a demographic outcome.

Population: Data only provided for those who proceeded to data collection (N=8)

VO2peak is used to describe the cardiorespiratory fitness of the participants

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=6 Participants
All participants engaged in treadmill exercise training
Peak Aerobic Power (VO2peak)
31.1 ml/kg/min
Standard Deviation 8.49

OTHER_PRE_SPECIFIED outcome

Timeframe: BMD of the total hip is measured at baseline

Population: Total hip BMD is only reported for those who proceeded to data collection (N=8).

BMD is used to describe the bone health status of the participants

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=8 Participants
All participants engaged in treadmill exercise training
Bone Mineral Density (BMD)
0.967 g/cm^2
Standard Deviation 0.097

OTHER_PRE_SPECIFIED outcome

Timeframe: FM is measured at baseline

Population: Data is only available for those who proceeded to data collection (N=8)

FM is used to describe the body composition of participants

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=8 Participants
All participants engaged in treadmill exercise training
Fat Mass (FM)
24.7 kg
Standard Deviation 6.5

OTHER_PRE_SPECIFIED outcome

Timeframe: FFM is measured at baseline

Population: Data only available for those who proceeded to data collection (N=8).

FFM is used to describe the body composition of participants

Outcome measures

Outcome measures
Measure
Aerobic Exercise
n=8 Participants
All participants engaged in treadmill exercise training
Fat-free Mass (FFM)
56.9 kg
Standard Deviation 9.0

Adverse Events

Aerobic Exercise

Serious events: 0 serious events
Other events: 2 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
Aerobic Exercise
n=8 participants at risk
All participants engaged in treadmill exercise training
Musculoskeletal and connective tissue disorders
Musculoskeletal pain
25.0%
2/8 • From enrollment to 24 hours after the final exercise bout, up to 12 weeks.
Adverse event information is only reported for those who proceeded to data collection as there were no adverse events associated with the screening procedures.

Additional Information

Sarah Wherry, PhD, Research Health Scientist

VA Eastern Colorado Health Care System

Phone: 303-704-8054

Results disclosure agreements

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