Analysis of the Relationship between Sleep Duration and Body Mass Index in a South Korean Adult Population: A Propensity Score Matching Approach

BACKGROUND: One-third of the present adults in South Korea are obese, and previous studies have demonstrated that sleep duration is considered a risk factor for obesity. Hence, I assessed the relationship between sleep duration and body mass index in a South Korean adult population. METHODS: This cross-sectional study consists of a representative sample of 4,218 South Korean adults (20–64 years) who participated in the sixth Korea National Health and Nutrition Examination Survey (2015). As statistical analysis methods, data were analyzed using chi-square test and multiple logistic regression. Propensity score matching (PSM) was applied to control selection bias, and obesity-related factors were used as covariates in PSM. RESULTS: According to the multiple logistic regression analysis, people who sleep for more than seven hours a day were less likely to be obese than those who sleep for less than seven hours a day in the pre-match (OR = 0.75, 95%CI = 0.65–0.88) and post-match (OR = 0.77, 95%CI = 0.65–0.90) samples. CONCLUSIONS: This finding suggests that South Korean adults who reported sleeping more than 7 hours a day were linked to decreased body mass index. Hence, the proper amount of sleep is necessary to reduce the prevalence of obesity in this population.