[Influence of sleep fragmentation in infancy and toddler period on emotional and behavioral problem at the age of 6 years: a birth cohort study].

To investigate the influence of sleep fragmentation in infancy and toddler period on emotional and behavioral problems at the age of 6 years. Using a prospective cohort design, 262 children were extracted from mother-child birth cohort recruited from May 2012 to July 2013 in Renji Hospital, School of Medicine, Shanghai Jiao Tong University. Children's sleep and physical activities were assessed using actigraphy at 6, 12, 18, 24, and 36 months of age, from which the sleep fragmentation index (FI) at each follow-up point was calculated. Children's emotional and behavioral problems at 6 years of age were assessed using the strengths and difficulties questionnaire. Group-based trajectory model was applied to determine sleep FI in infancy and toddler period trajectory groups with Bayesian information criteria being used to determine the best fitting model. Children's emotional and behavioral problems between groups were examined with independent test and linear regression models, etc. A total of 177 children, with 91 boys and 86 girls, were included in the final analysis and were divided into 2 groups: high FI group (=30) and low FI group (=147). Compared with children in the low FI group, those in the high FI group presents with higher total difficulties score and higher hyperactivity or inattention score ((11.0±4.9) (8.9±4.1), (4.9±2.7) (3.7±2.3) scores, =2.17, 2.23, both <0.05, respectively), with the differences remaining significant after adjusting for covariates (=2.08, 2.09, both 0.05 respectively). High sleep fragmentation in infancy and toddler period is associated with more emotional and behavioral problems, especially hyperactivity or inattention problems, at 6 years of age.