[Pilot study on the differences of young male's sleep structure and quality between indigenous Tibetans and longtime Han residents in high altitude area].

Objective: To compare young males' sleep quality and structure between native Tibetans and longtime Han residents.
Methods: A total of 14 male Tibetans and 11 male Hans at an altitude of 3 780 m were enrolled in this study. Tibetans were native highlanders with a mean age of (32.0 ± 9.1) years. Han subjects were born and living in high altitude with a mean age of (36.6 ± 7.6) years. All subjects were monitored by Polysomnography(PSG), and the differences of sleep structure and quality between the two groups were compared according to the international standard.
Results: The sleep efficiency (93.1% ± 3.9% vs 85.7% ± 4.2%) and nocturnal oxygen saturation (SpO(2)) (89.4% ± 2.0% vs 84.6% ± 4.3%) in Tibetans was significantly higher than those in Hans (both P<0.05). The number of awakening ((1.9 ± 0.8) vs (4.1 ± 1.3)/h) and micro-awakening ((23.4 ± 5.8) vs (28.7 ± 4.1)/h), the oxygen reduction index ((11.7 ± 4.8) vs (16.3 ± 7.5)/h), apnea hypoventilation index (AHI) ((5.8 ± 2.3) vs (9.6 ± 4.2)/h) and average heart rate ((66.9 ± 8.3) vs (79.9 ± 6.7)/min) of Tibetans were significantly lower than Hans (all P<0.05). Tibetans had longer slow wave sleep (20.1% ± 7.2% vs 8.8% ± 3.3%) and the Hans had longer stage 2 of non-rapid eye movement (NREM) (31.1% ± 11.9% vs 18.4% ± 6.7%) and shallow sleep (76.1 ± 11.7 vs 70.8 ± 11.2) (all P<0.05).
Conclusion: Tibetans have better sleep quality and higher sleep efficiency than Han residents at high altitude.