Short nighttime sleep-duration and hyperactivity trajectories in early childhood.

OBJECTIVES Our objectives were to investigate the developmental trajectories of nighttime sleep duration and hyperactivity over the preschool years and to identify the risk factors associated with short nighttime sleep duration and high hyperactivity scores. DESIGN, SETTING, AND PARTICIPANTS Nighttime sleep duration and hyperactivity were measured yearly by questionnaires administered to mothers of 2057 children from age 1.5 to 5 years. Developmental trajectories of nighttime sleep duration and hyperactivity throughout early childhood were analyzed to determine interassociations. A multinomial logistic regression was performed to determine which factors among selected child, maternal, and family characteristics and parental practices surrounding sleep periods in early childhood were associated with short nighttime sleep duration and high hyperactivity scores. RESULTS The trajectories of nighttime sleep duration and hyperactivity were significantly associated. The odds ratio (OR) of reporting short nighttime sleep duration was 5.1 for highly hyperactive children (confidence interval [CI]: 3.2-7.9), whereas the OR of reporting high hyperactivity scores was 4.2 for persistently short sleepers (CI: 2.7-6.6). The risk factors for reporting short nighttime sleep duration and high hyperactivity scores were (1) being a boy, (2) having insufficient household income, (3) having a mother with a low education, and (4) being comforted outside the bed after a nocturnal awakening at 1.5 years of age. CONCLUSIONS The risk of short nighttime sleep duration in highly hyperactive children is greater than the risk of high hyperactivity scores in short sleepers. Preventive interventions that target boys living in adverse familial conditions could be used to address these concomitant behavioral problems.