[Association between pubertal timing and tempo with sleep duration in children]

Objective: To evaluate the association between pubertal timing and tempo with sleep duration in children. Methods: A total of 2 288 students from grade 1 to 3 were recruited from 3 primary schools in Bengbu, Anhui Province in 2013 by convenient sampling method, and a child health and development cohort was established and a baseline survey was conducted, followed by 4 follow-up surveys in 2015, 2017, 2018 and 2019. Each survey included a questionnaire survey, a physical examination and an assessment of pubertal development. Tanner stage of testicular volume in boys and breast development in girls were evaluated objectively by visual examination combined with palpation. The nonlinear growth model was used to evaluate the timing and tempo of puberty. After controlling confounding factors, generalized estimation equations were used to evaluate the association between pubertal timing and tempo and the 6-year sleep duration in children. Results: A total of 1 903 children with age of (8.10±0.87) years were enrolled, including 1 056 boys (55.50%). After adjusting for confounds, compared with children in normal timing group, children in early timing group had a decrease of 0.19 hours (β=-0.19,95%CI:-0.30- -0.07, P=0.001) in sleep duration in 6 years, while children in late timing group had an increase of 0.14 hours (β=0.14, 95%CI: 0.01-0.28, P=0.041) in sleep duration in 6 years. Compared with children in normal tempo group, children in slow tempo group had a decrease of 0.16 hours (β=-0.16, 95%CI: -0.30- -0.02, P=0.021) in sleep duration in 6 years. Conclusions: Compared with children in normal timing group, the sleep duration of children in early timing group decreased, while the sleep duration of children in late timing group increased. Compared with normal tempo group, the sleep duration of the children in slow tempo group decreased.