Clinical trial NCT04801810: Daily Low Oxygen Exposure and Weight Status
Official title: Effects of Daily Low Oxygen Exposure on Weight Status, Body Composition, and Metabolic Health
Study type: INTERVENTIONAL
Overall status: WITHDRAWN
Phase: NA
Conditions: Overweight and Obesity
Keywords: Body weight
Normobaric hypoxia
Overwieght and obesity
Negative energy balance
Energy expenditure
Energy intake
Lead sponsor: Florida State University
Sponsor class: OTHER
First posted: 2021-03-17
Enrollment: 0
Sex: ALL
Minimum age (years): 20
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The objective of this single-blind, parallel-arm, randomized clinical trial is to evaluate changes in body weight and composition, assess determinants of energy balance, and measure modulators of energy intake and expenditure, following 8 wk of calorie restriction (CR, -500 kcal/d) in combination with either overnight exposure (8 h/night) to normobaric hypoxia (NH; 15% oxygen, \~8500 ft elevation) or normoxia (NN; 21% oxygen, sea level), using a commercially available, in-home tent system, in adults who are overweight or obese.

Detailed description: The current research study will evaluate changes in body weight and composition, assess determinants of energy balance, and measure modulators of energy intake and expenditure, following 8 wk of calorie restriction (CR, -500 kcal/d) in combination with either overnight exposure to normobaric hypoxia (NH) or normoxia (NN). Participants will be instructed to follow their normal diet but with a 500 kcal/day deficit as advised by a Registered Dietitian. Participants will spend 8 hours/night in a tent, set-up around their bed, in their home, for 8 weeks. Participants sleeping in the hypoxic tent (Hypoxico Inc., New York, NY, commercially available tents: https://hypoxico.com/) will breath \~15% oxygen (achieved with nitrogen dilution, equivalent to \~8500 ft elevation), whereas those in the control tent (Hypoxico Inc.) will breath \~21% oxygen (achieved with nitrogen dilution, equivalent to sea level elevation). Trained research staff will set-up the hypoxic or control tent system in each participant's home on day 0 and will visit the participant's home on days 1, 2, and 3 to check and/or adjust the tent settings. After day 3, research staff will visit the participant's home weekly to check and/or adjust the tent settings. participants will be weighed each morning following an overnight fast and morning void. Participants will come to the laboratory on two separate days for baseline testing (days -1 and 0) and again on two separate days at the end of the study (days 55 and 56) for endpoint testing.

Eligibility criteria: Inclusion Criteria:

* Men and women aged 20 - 50 years
* Overweight or obese (BMI between 27.5-34.9 kg/m2)
* Born at altitudes less than 2,100 meters (\~7,000 feet)
* Currently residing in Tallahassee, Florida, or the surrounding area
* Not taking any medication(s) that interfere with metabolism or oxygen delivery/transport for 4 weeks prior to and throughout the entire study (e.g., includes sedatives, sleeping aids, tranquilizers, and/or any medication that depresses ventilation, diuretics, alpha, and beta-blockers).
* Willing to refrain from smoking, vaping, chewing tobacco, and dietary supplement use throughout the entire study
* Willing to have a hypoxic tent set-up in their home and spend 8 consecutive hours per night in the tent for 8 weeks
* Lives with a family member, partner/spouse, or roommate who can hear and respond in the unlikely event that the blood oxygen, air oxygen, or air carbon dioxide monitoring alarm would sound.

Exclusion Criteria:

* Living in areas that are more than 1,200 m (\~4,000 feet), or have traveled to areas that are more than 1,200 m for five days or more within the last 2 months
* Metabolic or cardiovascular abnormalities, gastrointestinal disorders, and any condition that interferes with metabolism or oxygen delivery/transport (e.g., kidney disease, diabetes, cardiovascular disease, etc.)
* Evidence of apnea or other sleeping disorders
* Evidence of prior high-altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE) diagnosis
* Diagnosis or family history of sickle cell anemia/trait
* Hematocrit \<42% for males, \<36% for females
* Hemoglobin \<13 g/dL for males, \<12 g/dL for females
* Blood donation within 8 weeks of beginning the study
* Present condition of alcoholism, anabolic steroids, or other substance abuse issues
* Allergies or intolerance to foods included in the standardized and ad libitum meal tests (e.g., lactose intolerance/milk allergy)
* Women who are pregnant, lactating, planning to become pregnant, or who have had an irregular menstrual cycle in the past 6 mo.
* Weight gain or loss \> 10% of body weight during the past 6 months
* Adults unable to consent
* Individuals who are not yet adults (infants, children, teenagers)
* Prisoners

Primary outcomes:
measure: Percent change in body weight
timeFrame: 8 weeks (56 days)
Secondary outcomes:
measure: Percent change in body weight
timeFrame: 4 weeks after intervention ends
measure: 4-compartment body composition using DEXA and deuterium dilution
timeFrame: Days -1 and 55
measure: Resting metabolic rate
timeFrame: Days 0 and 56
measure: Resting substrate oxidation
timeFrame: Days 0 and 56
measure: Total daily energy intake
timeFrame: Weeks -1, 1, 2, 4, 6, and 8
measure: Total daily macronutrient intake
timeFrame: Weeks -1, 1, 2, 4, 6, and 8
measure: Ad libitum energy intake
timeFrame: Days 0 and 56
measure: Food preferences
timeFrame: Days 0 and 56
measure: Heart rate variability
timeFrame: Days 0 and 56
measure: Urinary epinephrine
timeFrame: Days -1, 13, and 55
measure: Urinary norepinephrine
timeFrame: Days -1, 13, and 55
measure: Urinary dopamine
timeFrame: Days -1, 13, and 55
measure: Plasma glucose concentrations
timeFrame: Days 0 and 56
measure: Plasma insulin concentrations
timeFrame: Days 0 and 56
measure: Whole-body insulin sensitivity index
timeFrame: Days 0 and 56
measure: Thermic effect of glucose
timeFrame: Days 0 and 56
measure: Subjective appetite measures
timeFrame: Days 0 and 56
measure: Prevalence of acute mountain sickness
timeFrame: Days 0-7, 14, 21, 28, 35, 42, and 56
measure: Continuous overnight oxygen saturation
timeFrame: 8 weeks (56 days)
measure: Sleep quality
timeFrame: Days 0-7, 14, 28, 35, 42, and 56
measure: 24-hour continuous glucose concentrations
timeFrame: Days -7 to 0, 1 to 14, and 42 to 56
measure: 24-hour glucose variability
timeFrame: Days -7 to 0, 1 to 14, and 42 to 56
measure: Blood volume
timeFrame: Days -1 and 55
measure: Fasting measures of iron status
timeFrame: Days 0 and 56
measure: Psychosocial Factors
timeFrame: Days -1, 14, and 55
measure: Fasting blood pressure
timeFrame: Days 0 and 56
Other outcomes:
Locations:
city: Tallahassee
country: United States
facility: Florida State University
state: Florida
Study officials:
affiliation: Florida State University
name: Claire E Berryman, PhD
role: PRINCIPAL_INVESTIGATOR
References: