Although severe intermittent hypoxia (IH) is well known to induce deleterious cardiometabolic consequences, moderate IH may induce positive effects in obese individuals. The present study aimed to evaluate the effect of two hypoxic conditioning programs on cardiovascular and metabolic health status of overweight or obese individuals. In this randomized single-blind controlled study, 35 subjects (54 ± 9.3 yr, 31.7 ± 3.5 kg/m2) were randomized into three 8-wk interventions (three 1-h sessions per week): sustained hypoxia (SH), arterial oxygen saturation ([Formula: see text]) = 75%; IH, 5 min [Formula: see text] = 75% - 3 min normoxia; normoxia. Ventilation, heart rate, blood pressure, and tissue oxygenation were measured during the first and last hypoxic conditioning sessions. Vascular function, blood glucose and insulin, lipid profile, nitric oxide metabolites, and oxidative stress were evaluated before and after the interventions. Both SH and IH increased ventilation in hypoxia (+1.8 ± 2.1 and +2.3 ± 3.6 L/min, respectively; P < 0.05) and reduced normoxic diastolic blood pressure (-12 ± 15 and -13 ± 10 mmHg, respectively; P < 0.05), whereas changes in normoxic systolic blood pressure were not significant (+3 ± 9 and -6 ± 13 mmHg, respectively; P > 0.05). IH only reduced heart rate variability (e.g., root-mean-square difference of successive normal R-R intervals in normoxia -21 ± 35%; P < 0.05). Both SH and IH induced no significant change in body mass index, vascular function, blood glucose, insulin and lipid profile, nitric oxide metabolites, or oxidative stress, except for an increase in superoxide dismutase activity following SH. This study indicates that passive hypoxic conditioning in obese individuals induces some positive cardiovascular and respiratory improvements despite no change in anthropometric data and even a reduction in heart rate variability during IH exposure.

中文翻译：

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超重和轻度肥胖个体对被动低氧条件的心血管和代谢反应。

虽然众所周知严重的间歇性缺氧（IH）会导致有害的心脏代谢后果，但中等的IH可能会在肥胖者中产生积极的作用。本研究旨在评估两种低氧调理方案对超重或肥胖个体心血管和代谢健康状况的影响。在这项随机单盲对照研究中，将35名受试者（54±9.3岁，31.7±3.5 kg / m2）随机分为三组8周干预（每周3次，每次1小时）：持续性缺氧（SH），动脉血饱和度（[公式：请参见文字]）= 75％；IH，5分钟[公式：参见文字] = 75％-3分钟常氧；常氧 在第一个和最后一个缺氧条件训练期间测量通气，心率，血压和组织氧合。血管功能，血糖和胰岛素，脂质分布，干预前后评估一氧化氮代谢产物和氧化应激。SH和IH在缺氧时均增加通气（分别为+1.8±2.1和+2.3±3.6 L / min; P <0.05）并降低常氧舒张压（分别为-12±15和-13±10 mmHg; P < 0.05），而正常氧收缩压的变化不显着（分别为+3±9和-6±13 mmHg; P> 0.05）。IH仅能降低心率变异性（例如，在正常氧水平下连续正常RR间隔的均方根差为-21±35％； P <0.05）。SH和IH均未引起体重指数，血管功能，血糖，胰岛素和脂质分布，一氧化氮代谢产物或氧化应激的显着变化，除了SH后超氧化物歧化酶活性增加外。