Childhood Sleep Duration and Quality in Relation to Leptin Concentration in Two Cohort Studies

STUDY OBJECTIVES: Poor sleep in childhood is associated with increased obesity risk, possibly by affecting appetite-regulating hormones such as leptin. We examined short- and long-term sleep duration and quality in relation to leptin in two US pediatric cohorts. DESIGN: Analysis of data from two prospective cohort studies. SETTING: Population-based. Adolescent polysomnography assessments performed in a clinical research unit. PATIENTS OR PARTICIPANTS: Children in Project Viva (n = 655) and adolescents in the Cleveland Children's Sleep & Health Study (n = 502). INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: In Project Viva, mothers reported average child sleep duration annually from infancy through age 7, and we measured leptin at ages 3 and 7. In the Cleveland Children's Sleep & Health Study, we collected self-reported sleep duration, polysomnography-derived measures of sleep quality, and fasting leptin at ages 16-19. In sex-stratified linear regression analyses adjusted for sociodemographic characteristics and adiposity, chronic curtailed sleep was associated with lower leptin at age 7 in girls; a one-unit decrease in sleep score was associated with a 0.08 decrease in log leptin (95% CI: 0.01,0.15). The association was stronger in girls with greater adiposity (P = 0.01). Among adolescents, shorter sleep was associated with lower leptin in males; each one-hour decrease in sleep duration was associated with a 0.06 decrease in log leptin (95% CI: 0.00, 0.11). Sleep duration was not associated with leptin at other ages. Sleep quality indices were not associated with leptin. CONCLUSIONS: Our results suggest possible age-specific sexual dimorphism in the influence of sleep on leptin, which may partly explain inconsistencies in the literature.