Early sleep duration trajectories and children's cognitive development: a prospective cohort study

We aimed to investigate the association between sleep duration trajectories and cognitive performance in preschool-aged Chinese children. We included 2131 children from the Ma'anshan birth cohort (MABC) study. Sleep duration trajectories from 6 to 48 months of age were determined using the group-based trajectory modeling (GBTM). Children's intellectual development was assessed using the Wechsler Preschool and Primary Scale of Intelligence. Compared to those with a medium total sleep duration trajectory, children with a short total sleep duration trajectory had poorer cognitive performance on the Visual Spatial Index (VSI) (& beta; = -3.65; 95% CI = -6.77 to -0.53), which was associated with an increased risk of a low full-scale intelligence quotient (FSIQ) (OR = 1.60; 95% CI = 1.02 to 2.51). The short total sleep duration trajectory was associated with a low VSI compared with both the medium total sleep duration trajectory and the long total sleep duration trajectory. Compared to children with normal nighttime sleep duration and normal daytime sleep duration trajectories, children with short nighttime sleep and long daytime sleep duration trajectories, normal nighttime sleep and long daytime sleep duration trajectories, and short nighttime sleep and normal daytime sleep duration trajectories all had lower cognitive performance. The restricted cubic spline (RCS) also showed that children with and appropriate total sleep duration, an adequate nighttime sleep duration, and a moderate daytime sleep duration had higher FSIQ.Conclusions: The results of this study emphasize that a medium total sleep duration, adequate sleep at nighttime, and appropriate sleep in the daytime appear to be more beneficial for children's cognitive development.What is Known:& BULL; Sleep duration in infancy is strongly associated with neurocognitive development.What is New:& BULL; Medium and long total sleep duration trajectories are beneficial for children's cognitive performance compared to the short total sleep duration trajectory.& BULL; A medium total sleep duration, adequate sleep at nighttime and appropriate sleep in the daytime appear to be more beneficial for children's cognitive development.