NCT03293901

Brief Summary

This randomized cross-over study will identify physiological factors that underlie changes in bone metabolism that could affect skeletal injury risk, to include increases in parathyroid hormone (PTH) in response to militarily relevant exercise in females. The primary objective is to determine the hormone and calcium (Ca) response to multiple bouts of load carriage exercise in females. The investigators hypothesize that PTH will increase after multiple bouts of load carriage exercise and this increase will be due to disruption in Ca kinetics, specifically either a decrease in fractional intestinal Ca absorption (FCA) or changes in bone formation and/or resorption.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
21

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Jun 2018

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

August 10, 2017

Completed
2 months until next milestone

First Posted

Study publicly available on registry

September 26, 2017

Completed
9 months until next milestone

Study Start

First participant enrolled

June 16, 2018

Completed
1.8 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 18, 2020

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

March 18, 2020

Completed
Last Updated

December 21, 2022

Status Verified

December 1, 2022

Enrollment Period

1.8 years

First QC Date

August 10, 2017

Last Update Submit

December 20, 2022

Conditions

Nutritional StatusBones

Outcome Measures

Primary Outcomes (1)

  • Hormone response and calcium kinetics

    After dosing with dual stable calcium isotopes, changes in calcium kinetics (isotopic rations) will be measured in response to multiple bouts of a militarily relevant load carriage exercise or no exercise (rest) in females.

    Exercise or rest will occur on days 0, 2, and 4 and measures will be taken daily days 0-4. After a washout period, measures will be repeated 1-4 weeks later on days 0, 2, and 4 with whichever intervention was not performed during the first study period.

Secondary Outcomes (2)

  • Fractional calcium absorption

    Bone measurement will be taken at baseline and FCA will be measured once during each intervention (exercise or rest) on day 0.

  • Single nucleotide polymorphisms

    SNP measurement will be taken at baseline and calcium measurements will be taken daily on days 0-4 when undergoing exercise and daily on days 0-4 when there is no exercise (rest).

Study Arms (2)

Rest

NO INTERVENTION

Exercise

ACTIVE COMPARATOR

Militarily relevant exercise

Behavioral: Exercise

Interventions

ExerciseBEHAVIORAL

Treadmill exercise for 60 minutes with load carriage (weighted vest, 30% body weight) completed three times during the 6 day kinetic period.

Exercise

Eligibility Criteria

Age18 Years - 42 Years
Sexfemale(Gender-based eligibility)
Gender Eligibility DetailsEligibility based on female anatomical sex characteristics
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Women aged 18-42 years
  • No current or prior military service
  • Exercise 2-5 x/wk
  • Stable body weight for 2 months (±5 lbs)
  • Body mass index (BMI) between 19-26 kg/m2
  • VO2max between 35-50 ml·kg-1·min-1
  • Willing to discontinue use of dietary supplements and abstain from alcohol for the duration of the study
  • Have not donated blood within the last 8 weeks

You may not qualify if:

  • History of endocrine disorders (e.g., diabetes, uncontrolled thyroid dysfunction, hypoparathyroidism, or hyperparathyroidism)
  • History of bone-modifying disorders (e.g., osteogenesis imperfecta, osteopetrosis, or rickets)
  • History of cardiovascular or renal disease
  • Pregnancy or lactation in the last 6 months
  • Routine use of medications known to affect bone or calcium metabolism (e.g., thiazide diuretics, bisphosphonates, oral steroids)
  • A very restrictive diet or severe food allergies

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

United States Army Research Institute of Environmental Medicine

Natick, Massachusetts, 01760, United States

Location

MeSH Terms

Interventions

Exercise

Intervention Hierarchy (Ancestors)

Motor ActivityMovementMusculoskeletal Physiological PhenomenaMusculoskeletal and Neural Physiological Phenomena

Study Officials

  • Erin Gaffney-Stomberg, PhD, RD

    United States Research Institute of Environmental Medicine

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
BASIC SCIENCE
Intervention Model
CROSSOVER
Sponsor Type
FED
Responsible Party
SPONSOR

Study Record Dates

First Submitted

August 10, 2017

First Posted

September 26, 2017

Study Start

June 16, 2018

Primary Completion

March 18, 2020

Study Completion

March 18, 2020

Last Updated

December 21, 2022

Record last verified: 2022-12

Locations

US(1)