Gender-dependent association between sleep duration and overweight incidence in CHINESE school children: a national follow-up study

BACKGROUND: The relationship between sleep duration and overweight risk remains unexplored among Chinese children. This study aims to evaluate this association in a national investigation with school-aged population. METHODS: There were 18,302 normal weight children in this Chinese national study which conducted during 2013–2014 included in the research. Anthropometric measurements were performed both at baseline and after 6–9 month. Sleep duration, physical activity, food intake and social economic information were collected by self-report questionnaire. Overweight was defined according to the updated Chinese criterion. Cox regression was used to evaluate the relationships between sleep duration and overweight incidence with multivariable adjusted. RESULTS: In total, there were 443 new overweight cases recorded at the end of observation. Overweight incidence with greater than 9 h (long sleep duration, LSD), 7 to 9 h (middle sleep duration, MSD), and less than 7 h of sleep (short sleep duration, SSD) were 2.7, 3.1 and 3.3% respectively. Stratified by gender and compared with LSD, the hazard ratio (HR) of overweight for females with MSD was 1.60 (95% CI: 1.02–2.52). Stratified by age and gender, the HR in the group of MSD was 2.13 (1.20–3.77) in female aged 6–10 years and 0.24 (0.06–0.93) in female aged 15–17 years. CONCLUSION: The association between short sleep duration and overweight is age- and gender dependent. In group of small age and elder age, girls’ adiposity states are independently associated with sleep duration. Sleep recommendation is a potential preventive action for overweight/obesity among girls.