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

项目总结/摘要 肥胖和相关的代谢疾病是一个重大的公共卫生负担， 美国每年约1500亿美元。肥胖既是一种疾病，影响三分之一的美国人，也是一个风险因素 对于其他慢性疾病，如心血管疾病，2型糖尿病，和13种形式的 癌的饮食和运动是预防和治疗肥胖的基石。但 相当多的人对现有的减肥干预措施没有反应， 肥胖率继续上升。因此，需要非常规方法来补充 目前的减肥策略。每天暴露在低氧条件下可能有助于目前的体重- 损失策略。中等（1500-3500 m）和更高（≥ 3500 m）海拔环境 由于较低的大气压力（作为参考，科罗拉多州丹佛市约为1600 m）， 及Mt.俄勒冈州的胡德约3500米）。研究表明，海平面上的土著人暴露在中等- 或高海拔连续5天或以上体重下降，这是长期的后果 血液和组织氧合减少，导致能量消耗增加， 食欲下降。然而，实施缺氧作为减肥的手段已经被证明是可行的。 到目前为止，由于前往偏远地区或进入海拔高度的后勤限制， 室。一种安全、更便宜、后勤上更可行的替代方法是使用 商业上可获得的，低氧系统在海平面上，它创造了常压缺氧 环境无论是在家、过夜、常压缺氧暴露，与 常压常氧暴露，促进肥胖成年人体重减轻， 未知此外，能量平衡的决定因素，包括能量摄入和消耗， 它们对常压缺氧引起的体重减轻的相对贡献还没有被 研究了拟定的双盲、平行组、随机临床试验的目的是 评估体重和成分的变化，评估能量平衡的决定因素 （摄入量和支出），并测量能量平衡调节剂，8周后的热量 限制（~ 500 kcal/d）与常压缺氧过夜暴露（8 h/夜，15% FiO 2，~2640 m）或常氧（8 h/夜，21% FiO 2），使用市售的， 家庭帐篷系统，在肥胖的成年人。慢性（8周），夜间（8小时/夜）低 氧气暴露可以提供一种非常规的方法来补充当前的体重减轻 战略，告知新的战略，以加速减肥，援助长期体重管理 努力，并有益于肥胖个体的代谢健康。

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.