Abstract Body: Introduction: Hormone fluctuations and circadian rhythms, including the sleep-wake cycle, are reciprocally associated. Lipid and glucose metabolism pace depend on leptin and adiponectin levels. Alignment of the sleep-wake cycle is associated with optimal sleep duration and metabolic regulation. Therefore, deviations in sleep timing and duration resulting from circadian misalignment, which is highly prevalent in adolescents, are potentially impacting this association.
Hypothesis: Objective metrics of sleep timing and duration are associated with adiponectin and leptin levels in adolescents.
Methods: We assessed 344 adolescents from the Penn State Child Cohort [16.2 (2.2) years; 44.4% female; 21.5% racial/ethnic minority], of whom 215 were evaluated while in school and 129 while on break. All subjects had a minimum of 3-nights of at-home actigraphy and 9-hour in-lab polysomnography. Sleep midpoint (SM) was calculated as the central point of the sleep period, while sleep irregularity (SI) and sleep variability (SV) as the intra-individual standard deviation of the SM and total sleep time, respectively. Adiponectin and leptin levels were assayed via ELISA from blood samples. Linear regression models adjusted for sex, race/ethnicity, age, apnea/hypopnea index, BMI percentile, and SES.
Results: Greater SI and SV while attending school were associated with lower log-adiponectin levels (B=-0.155, SD=0.057, p=0.007 and B=-0.127, SD=0.054, p=0.021, respectively). SM was not significantly associated with either log-leptin or log-adiponectin levels.
Conclusions: Increased irregularity and variability in the timing and duration of sleep during the academic year affect glucose and fatty acid control mechanisms in adolescents. Our findings further support targeting sleep from a multidimensional standpoint to better prevent its impact on cardiometabolic health.
Support: National Institutes of Health (R01HL136587, UL1TR000127)