Tan Lu, Li Taomei, Luo Lian, Xue Xiaofang, Lei Fei, Ren Rong, Zhang Ye, He Jiaming, Bloch Konrad E, Tang Xiangdong
Sleep Medicine Center, West China Hospital, Sichuan University, Chengdu, People's Republic of China.
Department of Emergency, Diqing Tibetan Autonomous Prefectural People's Hospital, Shangri-La, People's Republic of China.
Nat Sci Sleep. 2022 Sep 1;14:1533-1544. doi: 10.2147/NSS.S371388. eCollection 2022.
Obstructive sleep apnea (OSA) is common both at low and high altitude. Since adaptations to high altitude and respiratory control may differ among Tibetans and Hans, we compared characteristics of sleep-disordered breathing in the two ethnic groups at high altitude.
This was a prospective observational study including 86 Tibetan and Han long-term (>5 years) high altitude residents with chief complaints of snoring and/or witnessed apnea underwent clinical evaluation and polysomnography at 3200 meters in Shangri-La, China.
In 42 Tibetans, 38 men, median (quartiles) age was 50.0 (41.0; 56.0)y, total apnea/hypopnea index (AHI) 53.9 (32.0; 77.5)/h, obstructive AHI 51.0 (28.0; 72.2)/h and central AHI 1.5 (0.2; 3.1)/h. In 44 Hans, 32 men, median (quartiles) age was 47.0 (43.5; 51.0)y, total AHI 22.2 (12.8; 39.2)/h, obstructive AHI 17.7 (12.0; 33.0)/h and central AHI 2.4 (0.5; 3.4)/h (p < 0.001 total and obstructive AHI vs Tibetans). In Tibetans, mean nocturnal oxygen saturation was lower [median 85.0 (83.0; 88.0)% vs 88.5 (87.0; 90.0)%] and obstructive apnea and hypopnea duration was longer [22.0 (19.6; 24.8) sec vs 18.3 (16.7; 20.6) sec] than in Hans (all p < 0.001). In regression analysis, Tibetan ethnicity, neck circumference and high-altitude living duration were the predictors of total AHI. We also found that with every 10/h increase in total AHI, there were an approximately 0.9 beat/min and 0.8 beat/min increase in mean heart rate during rapid eye movement (REM) and non-REM sleep and 1.9 mmHg and 2.0 mmHg increase in evening and morning systolic blood pressure.
Our data suggest that Tibetans presented more severe obstructive sleep apnea, hypoxemia and longer apnea duration compared to Hans at 3200 meters, which was correlated with higher heart rate and blood pressure suggesting a greater cardiovascular risk.
阻塞性睡眠呼吸暂停（OSA）在低海拔和高海拔地区都很常见。由于藏族和汉族对高海拔的适应及呼吸控制可能存在差异，我们比较了这两个民族在高海拔地区睡眠呼吸障碍的特征。
这是一项前瞻性观察性研究，纳入了86名藏族和汉族长期（>5年）居住在高海拔地区的居民，他们主要抱怨有打鼾和/或目击到的呼吸暂停，在中国香格里拉海拔3200米处接受了临床评估和多导睡眠监测。
42名藏族人中，男性38名，年龄中位数（四分位数间距）为50.0（41.0；56.0）岁，总呼吸暂停/低通气指数（AHI）为53.9（32.0；77.5）次/小时，阻塞性AHI为51.0（28.0；72.2）次/小时，中枢性AHI为1.5（0.2；3.1）次/小时。44名汉族人中，男性32名，年龄中位数（四分位数间距）为47.0（43.5；51.0）岁，总AHI为22.2（12.8；39.2）次/小时，阻塞性AHI为17.7（12.0；33.0）次/小时，中枢性AHI为2.4（0.5；3.4）次/小时（总AHI和阻塞性AHI与藏族相比，p<0.001）。与汉族相比，藏族夜间平均血氧饱和度更低[中位数85.0（83.0；88.0）%对88.5（87.0；90.0）%]，阻塞性呼吸暂停和低通气持续时间更长[22.0（19.6；24.8）秒对18.3（16.7；20.6）秒]（所有p<0.001）。在回归分析中，藏族、颈围和高海拔居住时间是总AHI的预测因素。我们还发现，总AHI每增加10次/小时，快速眼动（REM）睡眠和非REM睡眠期间平均心率分别增加约0.9次/分钟和0.8次/分钟，夜间和早晨收缩压分别升高1.9 mmHg和2.0 mmHg。
我们的数据表明，在海拔3200米处，藏族比汉族表现出更严重的阻塞性睡眠呼吸暂停、低氧血症和更长的呼吸暂停持续时间，这与更高的心率和血压相关，提示更大的心血管风险。
