Report on Childhood Obesity in China (10): Association of Sleep Duration with Obesity

Key words: 
• Sleep duration /
• Obesity /
• Children /
• China

Abstract: Objective To explore the association of sleep duration with obesity among children in urban areas of China.Methods A total of 6 576 children (3 293 boys and 3 283 girls) aged 7-11 years were randomly selected from 36 primary schools in 6 metropolitan cities in China.A 7-day Physical Activity Recall was used to assess the sleep duration and physical activity level.The height,weight,waist circumference (WC)and percentage of body fat (％BF,as determined by bioelectrical impedance analysis technique) were measured by following the standardized operation procedures.The information on demography,lifestyle and eating habits was collected with a self-administered questionnaire from participants and their parents.Results The average sleep duration per night in the children was 9.7 h with the decreasing trends along with the increase of age (P＜0.05).The sleep duration was negatively associated with body mass index (BMI) and WC in both boys and girls after adjustment for confounders (β value -0.23 and -0.82 for boys,-0.24 and -0.91 for girls,respectively,P＜0.01).However,no significant association of sleep duration with ％BF was found.Children who slept less than 9.0 h per night had a higher risk for overweight and obesity (0R=1.29,95％ CI:1.01,1.64) and abdominal obesity (OR=1.38,95％ CI:1.04,1.83) as compared with those who slept for 10.0-10.9 h.Conclusions Short sleep duration is associated with obesity.It is important to ensure adequate sleep duration of children and foster their healthy lifestyle at an early stage of life.