Sleep and insulin sensitivity in adolescents at risk of type 2 diabetes: the Sleep Manipulation in Adolescents at Risk of Type 2 Diabetes randomized crossover study

Study Objectives: To investigate the effect of increasing sleep duration for 1 week, compared to a week of habitual and decreased sleep, on insulin sensitivity (IS) in adolescents at risk for type 2 diabetes (T2D). Methods: Adolescents, 13-18 years old, at risk for T2D, with obesity and other risk factors, were recruited for a randomized (1:1), open-label, sex-stratified crossover study, that manipulated time-in-bed to modify sleep duration (measured by actigraphy). Following a week of habitual (HB) sleep, time-in-bed was increased (IN) and decreased (DE) by 1 hour 30 min/night for 1 week, counterbalanced across participants (HBINDE or HBDEIN), and separated by a week of washout sleep. The main outcome measure was IS, obtained via 2-hour oral-glucose-tolerance-test conducted after each sleep week. Results: Of the 43 participants recruited, 36 (84%) completed all sleep interventions (52.8% female, age = 15.1 years, body mass index = 99.9th percentile, order: HBINDE = 18 and HBDEIN = 18). On average, during the HB week, participants slept 7 hours 31 min/night; sleep duration was 1 hour 02 min/night higher during the IN week and 1 hour 19 min/night lower during the DE week. We found a significant effect of sleep week on IS with a large effect size. Following the IN sleep week, IS was 20% higher compared to after the HB and DE sleep weeks, but there was no significant difference in IS following HB versus DE sleep weeks. Conclusions: Whenever possible, clinicians should empower youth at risk of T2D to improve their sleep duration, since even a modest increase in sleep duration of 1 h/night for 1 week can have a positive impact on IS in this population.