Short Sleep Duration Combined with Obstructive Sleep Apnea is Associated with Visceral Obesity in Korean Adults

Study Objectives: To determine whether short sleep duration alone or combined with obstructive sleep apnea (OSA) is associated with regional body fat including abdominal visceral fat area (VFA) among Korean adults. Design: Cross-sectional study. Setting: Ansan, South Korea. Participants: There were 838 community participants age 40-69 y from the Korean Genome and Epidemiology Study. Measurements and Results: Subjective habitual sleep duration and OSA were defined based on a structured sleep questionnaire and a home portable sleep study, respectively. Abdominal VFA and hepatic fat components were assessed by computed tomography. Adjusted mean VFA and hepatic fat were highest in the shortest sleep duration group (< 5 h) and decreased linearly with increasing sleep duration. Individuals with OSA (apnea-hypopnea index >= 5) had a higher body mass index, waist circumference, percent body fat, VFA, and hepatic fat than those without OSA after adjusting for age and sex. The adjusted odds ratio (OR) for visceral obesity (VFA >= 100 cm(2)) was 2.05 (95% confidence interval [CI], 1.09-3.86) in individuals sleeping less than 5 h compared with those sleeping longer than 7 h, and 1.57 (95% CI, 1.08-2.26) in individuals with OSA compared with those without OSA, after adjusting for all confounding factors including body mass index. A combination of short sleep duration (< 5 h) and OSA substantially increased the OR for visceral obesity (OR, 4.40, 95% CI, 1.80-10.77) compared with those who slept longer (>= 7 h) without OSA. Conclusion: Short sleep duration and OSA are independently associated with visceral obesity in adults. The association is particularly strong in short sleepers with OSA.