The association between sleep duration, bedtimes, and early pubertal timing among Chinese adolescents: a cross-sectional study

Background and objective Early pubertal timing is associated with sleep among Western adolescents, but little is known about this association in Chinese adolescents, especially with regard to the association between bedtimes and early pubertal timing. This paper aimed to identify the association between sleep duration, bedtimes, and early pubertal timing in Chinese adolescents. Methods An anonymous cross-sectional survey was conducted among primary and junior middle students (grades 3 to 9) from QiJiang District, ChongQing, China. Participants were recruited by applying stratified cluster sampling. Pubertal timing, sleep duration, and bedtimes were assessed using the Pubertal Development Scale and a self-designed sleep questionnaire. We utilized multivariable logistic linear regression (MLLR) to test the association between sleep duration, bedtimes, and pubertal timing. Results A total of 5461 adolescents were evaluated, with mean age and BMI values of 11.41 +/- 2.05 and 18.03 +/- 3.03, respectively, of whom 1257 (23.02%) were in early pubertal timing. In MLLR controlling for age, BMI, family economic status, and other covariates, sufficient sleep (b= - 0.214,P= 0.032, OR = 0.808, 95% CI 0.664-0.982) was negatively related to early pubertal timing, and later bedtime (b= 0.195,P< 0.001, OR = 1.215, 95% CI 1.104-1.338) was positively associated with early pubertal timing. Conclusion Students with early pubertal timing had less sleep duration and later bedtimes, which may be the result of increased stress caused by physical and psychological changes. Therefore, more attention should be paid to pubertal health education for adolescents during puberty. Further longitudinal studies are needed to confirm the causality between sleep and early pubertal timing in Chinese adolescents.