Sixteen-Year Secular Trends in Sleep Duration Among Korean Children and Adolescents

Abstract

Objective This study aimed to analyze trends in adolescent sleep duration over a 16-year period according to sex, educational level, residential area, and obesity. Methods In this cross-sectional study, data from the 2007–2022 Korean National Health and Nutrition Examination Survey were analyzed. Total sleep duration was measured using a self-administered questionnaire, and a survey-weighted linear regression analysis, considering the survey year as a continuous variable, was performed to examine the trend. Total sleep duration trends were also analyzed across subgroups categorized according to sex, educational level, residential area, and obesity level. Results Total sleep duration showed an overall increasing trend in boys (coefficient=0.027, ptrend<0.001), but no substantial trend was observed in girls (coefficient=0.002, ptrend=0.816). In the residential area-specific analyses, total sleep duration increased only in boys whose residential areas were urban (coefficient=0.017, ptrend<0.001). When classified by educational level, statistically significant increases in total sleep duration were observed among elementary school graduates or less (coefficient=0.018, ptrend=0.001) and middle school graduates (coefficient=0.015, ptrend=0.015). Depending on the obesity level, total sleep duration increased in normal-weight and overweight boys (normal weight: coefficient=0.014, ptrend=0.003; overweight: coefficient=0.038, ptrend=0.025). Conclusion This study found increasing or stable trends in sleep duration among adolescents aged 13 to 18 in Korea, with variations observed across subgroups based on sex, residential area, educational level, and obesity status.