0770 The Effect of In-Home Sleep Extension on Insulin Sensitivity for Habitually Short-Sleeping Adolescents

Abstract Introduction The interplay of physiological and behavioral factors of adolescence that result in dramatically insufficient sleep may confer a notable cardiometabolic risk. Increasing sleep duration reverses the negative metabolic consequences of insufficient sleep in adults, but this has not been examined in youth. Thus, the current study aimed to evaluate the impact of in-home sleep extension on insulin sensitivity (Si) in habitually short-sleeping adolescents. Methods Twenty-six healthy adolescents obtaining ≤7h sleep on school nights (age=16.6±1.1, 69% female, 73% non-Hispanic White) completed a randomized crossover trial consisting of one week each of Typical Sleep (usual school schedule) and Sleep Extension (≥1h additional time in bed) during the academic year. Sleep was estimated via actigraphy, and an intravenous glucose tolerance test (IVGTT) measured Si following each condition. Spearman and Kendall correlations assessed associations and paired samples t-tests and Wilcoxon signed-rank tests examined change in variables from Typical Sleep to Sleep Extension. Results A significant association between sleep and insulin sensitivity was observed during Typical Sleep, with poorer Si associated with longer sleep onset latency (rho=-0.29, p=0.04), and greater variability in waketime (rho=-0.44, p=0.02) and sleep duration (rho=-0.43, p=0.03). During Sleep Extension, participants significantly increased sleep duration by 1.4±0.7h (Typical Sleep=5.59±0.82, Sleep Extension=6.95±0.83 h; p< 0.001) by shifting bedtimes to an earlier clock hour (Typical Sleep=00:34±01:12; Sleep Extension=23:10±00:57; p< 0.001). Si did not significantly change between conditions (p=0.52). However, a trend was observed for a decrease in fasting glucose during Sleep Extension compared to Typical Sleep (Typical Sleep=92.5±8.87; Sleep Extension=88.48±12.06 mg/dL; p=0.055). Conclusion Habitually short-sleeping adolescents were successful at increasing sleep duration during an in-home intervention, but Si did not change compared to Typical Sleep. Notably, sleep duration during Sleep Extension was still less than the 8-10 h of sleep per night recommended for adolescents. A sufficiently early bedtime that supports adequate sleep is a biological challenge for adolescents when wake times are fixed due to early school start times. Future research is recommended examining whether combining sleep extension with a circadian health intervention can have a larger impact on sleep and cardiometabolic outcomes in adolescents. Support (if any) NIH NIDDK K23DK117021; NIH BIRCWH 2K12HD057022; CTSA UL1TR002535