Vgontzas A N, Lin H-M, Papaliaga M, Calhoun S, Vela-Bueno A, Chrousos G P, Bixler E O
Department of Psychiatry, Sleep Research and Treatment Center, Penn State University College of Medicine, Hershey, PA 17033, USA.
Int J Obes (Lond). 2008 May;32(5):801-9. doi: 10.1038/ijo.2008.4. Epub 2008 Feb 5.
Many epidemiologic studies have reported that obesity is associated with short sleep duration. How the degree of obesity or other clinical characteristics of the obese individuals, such as sleep disturbances or emotional stress, define this relation is not known.
We studied a random sample of 1300 middle-aged men and women from the Penn State Cohort in the sleep laboratory for one night. Sleep disturbances were recorded as insomnia, excessive daytime sleepiness (EDS) or sleep difficulty. Chronic emotional stress was determined by the Minnesota Multiphasic Personality Inventory-2 (MMPI-2).
Obese individuals (body mass index, BMI>30) reported shorter duration of sleep, had a higher incidence of subjective sleep disturbances (47.4 vs 25.5%; P<0.01) and scored higher for chronic emotional stress than nonobese subjects. However, there was no difference in self-reported sleep duration between obese and nonobese individuals without subjective sleep disturbances, while both obese men and women with sleep complaints scored higher in the MMPI-2 compared to obese individuals without sleep complaints. The shortest sleep duration was reported by the obese insomniac patients (5.9 h), followed by obese with EDS (6.3 h) or sleep difficulty (6.6 h). The effect of chronic emotional stress was stronger than that of the BMI on the reported sleep duration, with a synergistic joint effect. The presence of a sleep disturbance was associated with a reduction of reported sleep by 18 min for men and 42 min in women, whereas a 10 kg m(-2) increase of BMI was associated with a 16 and 6 min decrease of sleep in men and women, respectively. Interestingly, there was no association between objective sleep duration and BMI.
Self-reported short sleep duration in obese individuals may be a surrogate marker of emotional stress and subjective sleep disturbances, whose detection and management should be the focus of our preventive and therapeutic strategies for obesity.
许多流行病学研究报告称，肥胖与睡眠时间短有关。肥胖程度或肥胖个体的其他临床特征（如睡眠障碍或情绪压力）如何界定这种关系尚不清楚。
我们在睡眠实验室对来自宾夕法尼亚州队列的1300名中年男性和女性进行了随机抽样研究，为期一晚。睡眠障碍记录为失眠、日间过度嗜睡（EDS）或睡眠困难。慢性情绪压力通过明尼苏达多相人格调查表-2（MMPI-2）确定。
肥胖个体（体重指数，BMI>30）报告的睡眠时间较短，主观睡眠障碍的发生率较高（47.4%对25.5%；P<0.01），慢性情绪压力得分高于非肥胖个体。然而，没有主观睡眠障碍的肥胖个体和非肥胖个体在自我报告的睡眠时间上没有差异，而有睡眠问题的肥胖男性和女性在MMPI-2中的得分均高于没有睡眠问题的肥胖个体。肥胖失眠患者报告的睡眠时间最短（5.9小时），其次是患有EDS的肥胖者（6.3小时）或睡眠困难者（6.6小时）。慢性情绪压力对报告睡眠时间的影响比BMI更强，存在协同联合效应。睡眠障碍的存在与男性报告的睡眠时间减少18分钟和女性减少42分钟有关，而BMI每增加10 kg m(-2)，男性和女性的睡眠时间分别减少16分钟和6分钟。有趣的是，客观睡眠时间与BMI之间没有关联。
肥胖个体自我报告的睡眠时间短可能是情绪压力和主观睡眠障碍的替代指标，对其检测和管理应成为我们肥胖预防和治疗策略的重点。
