Effect of 10-day Overnight Hypoxia Treatment on Whole Body Insulin Sensitivity (SLEEP HIGH Study)

Study Overview
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Brief Summary
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The purpose of this study is to look at how a reduction in oxygen levels (hypoxia) influences insulin sensitivity and carbohydrate metabolism. It is expected that 10 nights of exposure to moderate hypoxia (  15% O2, similar to conditions at an altitude of  7500 feet) will improve glucose metabolism.

Official Title
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Effect of 10-day Overnight Hypoxia Treatment on Whole Body Insulin Sensitivity (SLEEP HIGH Study)

Conditions
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Insulin Resistance

Intervention / Treatment
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* Other: Hypoxia Exposure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 20-45 years Male Obese category (BMI > 30 kg/m2) Healthy as assessed by a self-reported health questionnaire Non-smokers Weight stable over the past 3 months (<2kg fluctuation) Exclusion Criteria: Female Diabetes Sleep apnea Hypertension History of altitude sickness Individuals taking any chronic medications Individuals taking any stimulants Individuals taking beta-blockers Individuals with chronic alcohol consumption (>3 drinks per day) or drug abuse. Individuals unable to abstain from caffeinated beverage or alcohol the days of study testing Individuals with history disease or history of stroke

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Hypoxia Exposure<br>There was only one study arm: All participants slept in moderate hypoxia (see description below). | Other: Hypoxia Exposure<br>* Participants spent 10 consecutive nights (approximately 100 hours of exposure) in a hypoxic tent at   15% O2 (ca. 2400 m elevation).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Insulin sensitivity | Glucose disposal and oxidation were measured using a two-step hyperinsulinemic euglycemic clamp and indirect calorimetry. | Change from baseline to 10 nights of hypoxia exposure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in oxygen tension in adipose tissue | pO2 levels were measured in adipose tissue both under hypoxia and normal oxygen conditions (normoxia) via a dual temperature-oxygen tension probe. | Before and after 10 nights of hypoxia exposure | 
| Glucose uptake in myotubes | Glucose uptake assays were performed in the presence or absence of hypoxia on myotubes harvested from muscle biopsies. | Before 10 nights of hypoxia exposure | 
| Change in gene and protein expression | Gene and protein expression of some hypoxia-responsive and insulin-signaling markers were measured in biopsied muscle and adipose tissue via RT-PCR and Western blotting, respectively. | Before and after 10 nights of hypoxia exposure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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obesity, hypoxia, insulin sensitivity, altitude