Background: Early puberty increases the risk of diverse health outcomes during adolescence and beyond. Several studies have explored the links between short sleep duration and early puberty worldwide.
Objective: The current systematic review and meta-analysis aimed to evaluate the association be-tween sleep duration and early pubertal timing based on published evidence systematically.
Methods: We searched important electronic databases for articles that reported the association be-tween childhood sleep duration and puberty timing up to October 2020. A total of 848 papers were identified from the databases and manual search. Finally, 10 studies including 23752 participants were included in the meta-analysis. We calculated the pooled effect sizes using a random or fixed effects model as appropriate.
Results: There was a significant inverse association between sleep duration and the risk of early puberty, longer duration of sleep was associated with 0.34% decreased odds of early puberty (OR = 0.66, 95% CI = 0.58-0.77, I2 = 96.6%). In a subgroup analysis, when pubertal status was assessed by physical examination compared with Pubertal Development Scale (PDS) or Sexual Maturation Scale (SMS), the associations between sleep duration and age of puberty were attenuated. The pooled OR (95% CI) of studies measuring pubertal timing by PDS/SMS and Tanner stage were 0.50(0.37-0.69) and 0.91(0.77-1.09), respectively. When pooling effect sizes was limited to studies that had BMI level adjustment, the association of sleep duration and early puberty was not statistically significant anymore (OR = 0.95, 95% CI = 0.89-1.01).
Conclusion: Longer sleep duration is associated with a lower risk of early puberty in children. The association between sleep duration and risk of early puberty may be modified by other factors such as BMI. To clarify the effect of sleep duration on the risk of early puberty in children, further prospective studies are needed.