0883 Sleep and Circadian Health, Insulin Sensitivity, and Glycemic Control in Adolescents with Type 1 Diabetes

Abstract Introduction Insulin resistance and poor glycemic control are significant risk factors for cardiovascular disease for individuals with type 1 diabetes (T1D). Adolescents with T1D are at heightened risk for poor sleep and circadian health due to behavioral and physiologic aspects of T1D in combination with biological, psychosocial, and environmental factors of adolescence. Emerging evidence suggests an association between sleep and circadian health with insulin sensitivity (SI) and glycemic control among adults with T1D and healthy adolescents, but this has not been explored in adolescents with T1D. Methods Twenty-three adolescents with T1D underwent a cross-sectional assessment during the academic year with one week of in-home actigraphy and continuous glucose monitoring (CGM) followed by in-laboratory serial salivary melatonin sampling and hyperinsulinemic-euglycemic clamp. BodPod assessed free-fat mass (FFM). SI was expressed as steady-state glucose infusion rate (“M”) in mg/kg/FFM/min. Sleep variability was calculated as the standard deviation of weekday actigraphy-estimated sleep metrics. Duration between dim-light melatonin onset (DLMO) and bedtime was calculated to determine circadian phase angle. Pearson correlations examined associations between sleep and circadian variables with SI and glycemic control. Results Adolescents with T1D (age=15.9±1.1 years, 48% female, 91% non-Hispanic White, HbA1c=7.6±1.1%) obtained 6.7±0.8h sleep on weeknights. Greater nightly variability of time in bed (TIB) and sleep midpoint timing across the monitoring period were associated with worse SI (M mg/kg FFM/min; r=-0.43, p=0.045; and r=-0.44, p=0.04, respectively). Greater nightly variability in the duration of wake after sleep onset (WASO) was associated with poorer CGM metrics, including higher mean sensor glucose (r=0.62, p=0.006), less time in range (70-180mg/dL, r=-0.56, p=0.016), and higher standard deviation (r=0.51, p=0.031). A longer duration (wider phase angle) between DLMO and bedtime was associated with a higher CGM coefficient of variation (r=0.91, p=0.002). Conclusion Nightly variability in TIB, sleep timing, and WASO, and circadian phase angle may represent contributing mechanisms of poorer SI and glycemic control in adolescents with T1D. Further research is warranted examining the health impact of sleep and circadian health interventions in adolescents with T1D. Support (if any) Ludeman Center for Women’s Health Research; JDRF 2-SRA-2019-848-S-B and 2-SRA-2022-1144-M-B; CCTSI Maternal NIH NCATS UM1TR004399.