Short sleep duration and obesity: the role of emotional stress and sleep disturbances

Abstract

Objective: 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. Design: 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). Results: 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−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. Conclusion: 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.