Sleep and insulin sensitivity in adolescents at risk of type 2 diabetes: the Sleep Manipulation in Adolescents at Risk of Type 2 Diabetes (SMART2D)randomized crossover study

Sleep. 2023 Dec 9:zsad313. doi: 10.1093/sleep/zsad313. Online ahead of print.


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, 13-18y 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 1h30min/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-h 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=15.1y, body-mass-index=99.9th percentile, order: HBINDE=18 and HBDEIN=18). On average, during the HB week, participants slept 7h31min/night; sleep duration was 1h02min/night higher during the IN week and 1h19min/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.

Conclusion: Whenever possible, clinicians should empower youth at risk of T2D to improve their sleep duration, since even a modest increase in sleep duration of 1h/night for one-week can have a positive impact on IS in this population.

Keywords: Adolescents; experimental study; insulin resistance; insulin sensitivity; obesity; sleep duration; sleep manipulation; type 2 diabetes.