Effects of daily low oxygen exposure on weight status, body composition, and metabolic health

Project Summary/Abstract
Obesity and associated metabolic conditions are a significant public health burden, costing the
U.S. ~$150 billion annually. Obesity is both a disease, affecting 1 in 3 Americans, and a risk factor
for other chronic diseases, such as cardiovascular disease, type 2 diabetes, and 13 forms of
cancers. Diet and exercise are the cornerstone of obesity prevention and treatment. However, a
considerable number of individuals are non-responsive to existing weight-loss interventions and
obesity rates continue to rise. Therefore, non-conventional approaches are needed to supplement
current weight-loss strategies. Daily exposure to low-oxygen conditions may aid in current weight-
loss strategies. Moderate (1500-3500 m) and higher (≥ 3500 m) altitude environments are
naturally hypoxic due to the lower atmospheric pressure (for reference, Denver, CO is ~1600 m
and Mt. Hood in Oregon is ~3500 m). Studies show that sea-level natives exposed to moderate-
or high- altitude continuously for 5 or more days lose weight, which is a consequence of prolonged
reductions in blood and tissue oxygenation that lead to increased energy expenditure and
decreased appetite. However, implementation of hypoxia as a means for weight loss has been
limited, to date, by the logistical constraints of traveling to remote locations or access to an altitude
chamber. A safe, less expensive, and more logistically feasible alternative is the use of
commercially available, low-oxygen systems at sea level, which create a normobaric hypoxic
environment. Whether in-home, overnight, normobaric hypoxic exposure, compared to
normobaric normoxic exposure, promotes body mass loss in adults with obesity remains
unknown. Furthermore, determinants of energy balance, including energy intake and expenditure,
and their relative contribution to normobaric hypoxia-induced weight loss have not been
investigated. The objective of the proposed double-blind, parallel-arm, randomized clinical trial is
to evaluate changes in body weight and composition, assess determinants of energy balance
(intake and expenditure), and measure modulators of energy balance, following 8 wk of calorie
restriction (-500 kcal/d) in combination with either overnight exposure to normobaric hypoxia (8
h/night, 15% FiO2, ~2640 m) or normoxia (8 h/night, 21% FiO2), using a commercially available,
in-home tent system, in adults with obesity. Chronic (8 weeks), overnight (8 hours/night) low
oxygen exposure may provide a non-conventional approach to supplement current weight-loss
strategies, inform new strategies to accelerate weight loss, aid long-term weight management
efforts, and benefit metabolic health in individuals with obesity.

Grant Number: 5R01DK127162-05
NIH Institute/Center: NIH
Principal Investigator: Claire Berryman