Night-sleep Duration Trajectories and Behavior in Preschoolers: Results from a Prospective Birth Cohort Study.

Background: Short sleep duration is associated with concomitant behavioral difficulties, but the longitudinal association between sleep duration and later behavior in early childhood remains unclear. The aim was to study the association between sleep duration trajectories throughout preschool and behavior at age 5-6 years.Participants: 1021 children of the French birth-cohort EDEN were included in this study.Methods: Night-sleep duration trajectories were modeled on the basis of repeated measures collected at age 2, 3 and 5-6 years by parental questionnaires. Behavior was assessed with the Strengths and Difficulties Questionnaire (SDQ), with five subscales measuring conduct problems, emotional symptoms, peer relation problems, antisocial behavior, and hyperactivity-inattention problems. The subscales were dichotomized by the 25th percentile. Multivariable logistic regression, adjusted for baseline behavior, and assessment of multiple confounding factors allowed for studying the independent association between night-sleep duration trajectories from age 2 to 5-6 and behavior at age 5-6.Results: Five distinct sleep-duration trajectories were identified. At age 5-6 years, probability of hyperactivity-inattention problems was increased for boys belonging to the "short sleep" and "medium-low sleep" duration trajectory and girls belonging to the "changing sleep" duration trajectory as compared with children with the medium-high sleep duration trajectory (boys: OR 2.69 [95% CI 1.18-6.16], p = .03 and 1.95 [1.25-3.03], p = .003, and girls: OR 2.79 [1.09- 7.17], p = .03). No associations were observed with the other SDQ subscales.Conclusion: The persistence of short night-sleep durations in preschool years as well as a sudden decrease at age 3 are risk factors of hyperactivity-inattention problems at school start.Abbreviations: SS: short-sleep duration trajectory; MLS: medium-low-sleep duration trajectory; MHS: medium-high-sleep duration trajectory; LS: long-sleep duration trajectory; CS: changing-sleep duration trajectory.