0918 Association of Physical Activity with Multidimensional Sleep Health in Adolescents: Impact of Weight Gain Since Childhood

Introduction Adolescents have unique sleep needs that impact their physical and mental wellbeing. The adolescent transition is also characterized by decreases in physical activity (PA) and increases in sedentary behavior (SB), which may have further deleterious effects on sleep beyond weight gain and obesity. Few longitudinal studies have examined synergistic effects between PA/SB and weight gain on sleep health in the transition from childhood to adolescents. Methods We studied 341 subjects from the Penn State Child Cohort aged 5-12 years old (median 9 years old) at baseline and 12-23 years old (median 16 years old) at follow-up (53% male, 21% racial/ethnic minority) who underwent in-lab polysomnography (PSG), had at least 3 valid nights of actigraphy (ACT) and completed self-reported questionnaires. The primary outcome was a data-driven, multivariable, multimethod sleep health score adapting the RU-SATED framework to include Breathing, Efficiency, Duration, REgularity, Satisfaction, and Timing (BEDREST) measured by PSG, ACT and self-reports. The BEDREST score ranged from 0 to 6, with higher values indicating better sleep health. Predictors included ACT-measured SB and moderate-to-vigorous PA (MVPA). Moderators included body mass index (BMI) and waist circumference (WC) and their change (Δ) from childhood to adolescence. Linear regression adjusted for age, sex, race/ethnicity, socioeconomic status, being in-school, internalizing symptoms, and externalizing behaviors as well as height and childhood values, as appropriate. Results Longitudinally, ΔWC modified the association of SB (p-interaction < 0.001) and MVPA (p-interaction = 0.023) with BEDREST score; a modifying role that was weaker for ΔBMI (p-interaction = 0.060). Among children who gained most central adiposity (ΔWC≥24cm), greater SB was associated with a lower BEDREST score (Est=-2.04, SE=0.42, p< 0.01). Cross-sectionally, WC (p-interaction=0.021) and BMI (p-interaction=0.020) modified the association of SB, but not MVPA, with BEDREST score. Among obese adolescents (BMI%≥95), greater SB was associated with a lower BEDREST score (Est=-1.04, SE=0.39, p=0.01). Conclusion Being sedentary negatively impacts sleep health among adolescents who gain central adiposity since childhood and are obese in adolescence. Less MVPA positively impacts sleep health in a small group of adolescents who lost central adiposity since childhood, which may suggest adequate timing of exercise. Support (if any) R01HL136587