Planetary Habitat Simulation: Bone Metabolism Studies

Summary

Bone losses are well known to occur in response to unloading (in microgravity or during immobilisation) and in patients with chronic obstructive airway disease (COPD). However, it is unknown whether there is an interactive effect between hypoxia and musculoskeletal unloading upon bone and mineral metabolism. Fourteen non-obese men, who are otherwise healthy, will undergo 3x 21-day interventions; normobaric normoxic bed rest (NBR; FiO2=21%), normobaric hypoxic ambulatory confinement (HAMB; FiO2=14%; \~4000 m simulated altitude), and normobaric hypoxic bed rest (HBR; FiO2=14%). The effects of hypoxia and bedrest on bone metabolism and phosphor-calcic homeostasis will be assessed (before and during each intervention, and 14 days after each intervention period) using venous blood sampling, 24hr urine collections, and peripheral quantitative computerized tomography (pQCT).

Conditions

• Hypoxia
• Bone Resorption

Interventions

OTHER

Hypoxia

21 days confinement in normobaric hypoxic (FiO2 = 14%)

OTHER

Ambulatory

Participants hava a standardized activity level throughout the intervention

OTHER

Normoxia

21 days confinement in normobaric normoxic (FiO2 = 21%) environment

OTHER

Bed Rest

Participants remain on supine bed rest throughout the intervention

OTHER

Standardised nutritional intake

Macronutrient, salt and dietary energy intake will be standardized per kg body weight for each participant

Sponsors & Collaborators

• Jozef Stefan Institute

  collaborator OTHER

• DLR German Aerospace Center

  collaborator OTHER

• KTH Royal Institute of Technology

  collaborator OTHER

• European Commission

  collaborator OTHER

• University of Nottingham

  lead OTHER

Principal Investigators

• Igor Mekjavic, PhD · Jozef Stefan Institute

• Jörn Rittweger, MD, PhD · German Aerospace Center (DLR)

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

25 Years

Max Age

45 Years

Sex

MALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2012-03-31

Primary Completion

2013-11-30

Completion

2015-09-30