ABSTRACT
BACKGROUND: The purpose of this study was to investigate the association between number of sleep hours and obesity based on body mass index (BMI) after adjusting for socioeconomic position, health behaviors, and clinical factors. METHODS: Data from subjects aged 20-64 years (n=12,688) in the Korea National Health and Nutrition Examination Survey in 2007-2009 was analyzed. Subjects were divided into two groups according to age: 20-44 (young adults) and 45-64 years (middle-aged adults). With respect to sleep time, subjects were classified as short sleepers (<6 hr/day), long sleepers (≥9 hr/day), and normal sleepers (6-8.9 hr/day). Obesity was defined as a BMI ≥25. RESULTS: The proportion of patients who were obese was 27.8%. The distribution of short sleepers, long sleepers, and normal sleepers was 6.4%, 13.7%, and 79.9%, respectively. The adjusted short sleeper and long sleeper odds ratios (OR) for obesity in young adults were significantly different from that in middle-aged adults after adjustment for confounding factors. In women, the adjusted short sleeper OR for obesity was 1.56 (95% CI, 1.02-2.37). CONCLUSION: This community-based random sample of Korean adults showed that women with short sleep duration may be at significant risk of obesity.