Planetary Habitat Simulation: Nutrition Studies

NCT02293772 | Completed DMC

• 1 other identifier: 284438/WP5
• Study Type: interventional
• Target: 14
• Locations: 0 countries
• Sites: N/A

Brief Summary

A loss of body weight has been documented in lowland-living individuals when exposed to hypoxic environments, such as at high altitude, or under laboratory conditions. A reduction in appetite and energy intake has also been reported during conditions of microgravity, such as during space flight. Fourteen normal or over-weight 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 appetite and its hormonal control will be assessed before and at day 17 of each intervention using a mixed meal tolerance test.

Conditions

Hypoxia

Keywords

Bedrest; Appetite

Outcome Measures

Primary Outcomes (1)

• Postprandial whole blood glucose concentration

  a fasted sample and a sample taken every 10mins for 2hrs following eating, before and after 17days of intervention

  2hrs

Secondary Outcomes (18)

• Postprandial serum insulin concentration

  2hrs

• Postprandial serum C-Peptide concentration

  2hrs

• Fasting serum leptin concentration

  early morning fasted sample

• Fasting serum adiponectin concentration

  early morning fasted sample

• Fasting serum total cholesterol concentration

  early morning fasted sample

Study Arms (3)

Hypoxic ambulatory

ACTIVE COMPARATOR

Ambulatory in normobaric hypoxia

Other: Hypoxic ambulatory

Hypoxic Bedrest

EXPERIMENTAL

Bedrest in normobaric hypoxia

Other: Hypoxic Bedrest

Normoxic bedrest

ACTIVE COMPARATOR

Bedrest in normobaric normoxia

Other: Normoxic Bedrest

Interventions

Hypoxic ambulatory OTHER

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

Hypoxic ambulatory

Hypoxic Bedrest OTHER

21 days supine bedrest in normobaric hypoxic (FiO2 = 14%) environment

Hypoxic Bedrest

Normoxic Bedrest OTHER

21 days supine bedrest in normobaric normoxic (FiO2 = 21%) environment

Normoxic bedrest

Eligibility Criteria

• Age: 25 Years - 45 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Physically and mentally healthy subjects
• Body mass index \< 25 kg/m2
• Height 158 - 190 cm
• Waist circumference \< 94 cm
• Volunteers that are able to declare their willingness to participate in the entire study
• Willing to be assigned randomly to the three groups
• Successfully passing the psychological and medical screening
• competent to sign informed consent
• Slovenian social insurance
• English language fluency

You may not qualify if:

• Medication required that may interfere with the interpretation of the results
• Bone mineral density (as measured by DEXA) more than 1.5 standard deviations \< t score
• Recent sub-standard nutritional status
• Family history of thrombosis or positive response in thrombosis screening procedure.
• (Biochemical analysis of the following parameters: ATIII, High sensitive C-reactive protein, S-Akt., Factor V-Leiden, Prothrombin, Lupus-partial thromboplastin time, Factor II)
• History of: thyroid dysfunction, renal stones, diabetes, allergies, hypertension, hypocalcemia, uric acidaemia, lipidaemia, or hyperhomocysteinaemia
• Gastro-esophageal reflux disease or renal function disorder, Hiatus hernia
• History of medical illness
• Smoker within six months prior to the start of the study
• Abuse of drugs, medicine or alcohol
• Participation in another study up to two months before study onset
• No signed consent form before the onset of the experiment
• Blood donors in the past three months before the onset of the experiment
• Vegetarian and Vegans
• Migraines

Sponsors & Collaborators

• University of Nottingham: lead
• Jozef Stefan Institute: collaborator
• KTH Royal Institute of Technology: collaborator
• European Commission: collaborator

Related Publications (3)

• Simpson EJ, Debevec T, Eiken O, Mekjavic I, Macdonald IA. PlanHab: the combined and separate effects of 16 days of bed rest and normobaric hypoxic confinement on circulating lipids and indices of insulin sensitivity in healthy men. J Appl Physiol (1985). 2016 Apr 15;120(8):947-55. doi: 10.1152/japplphysiol.00897.2015. Epub 2016 Jan 14.

  PMID: 26769956 RESULT

• Debevec T, Bali TC, Simpson EJ, Macdonald IA, Eiken O, Mekjavic IB. Separate and combined effects of 21-day bed rest and hypoxic confinement on body composition. Eur J Appl Physiol. 2014 Nov;114(11):2411-25. doi: 10.1007/s00421-014-2963-1. Epub 2014 Aug 5.

  PMID: 25091855 RESULT

• Debevec T, Simpson EJ, Mekjavic IB, Eiken O, Macdonald IA. Effects of prolonged hypoxia and bed rest on appetite and appetite-related hormones. Appetite. 2016 Dec 1;107:28-37. doi: 10.1016/j.appet.2016.07.005. Epub 2016 Jul 6.

  PMID: 27395413 RESULT

MeSH Terms

Conditions

Hypoxia

Condition Hierarchy (Ancestors)

Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Igor Mekjavic, PhD

  Jozef Stefan Institute

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Senior Research Fellow

Study Record Dates

• First Submitted: November 13, 2014
• First Posted: November 18, 2014
• Study Start: March 1, 2012
• Primary Completion: November 1, 2013
• Study Completion: October 1, 2014
• Last Updated: March 15, 2019

Record last verified: 2019-03

Data Sharing

• IPD Sharing: Will not share