Puja Batch

Introduction: Data from cross-sectional, longitudinal, meta-analytic, and experimental studies consistently link insufficient sleep to decreased cognitive ability and adverse cardiometabolic risk, including impaired insulin sensitivity. Despite the consistency of this data, there are a limited number of studies examining the potential health benefits of extending sleep duration in people with habitual insufficient sleep. This project explores the efficacy of extending sleep duration on health outcomes.

Methods: 38 healthy participants aged 23.3±5.0 years old (mean±SD), BMI 22.5±2.4 kg/m2 with self-reported sleep <6.5h/night completed the study. The protocol consists of two weeks of baseline monitoring followed by a four-week sleep extension intervention designed to increase time in bed by 2h/night. Outcomes were sleep duration and staging (Dreem Headband), Epworth Sleepiness Scale (ESS), and insulin sensitivity (oral glucose tolerance test), collected at baseline and post-intervention.

Results: Results show sleep extension increased (all p<0.05) total sleep time (mean ± SD), stage 1, stage 2 and REM sleep, and decreased (p<0.05) ESS (less sleepy). Additionally, the increase in stage 1 and 2 sleep was associated (p<0.05) with the decrease in ESS. However, there were no significant changes in stage 3 deep sleep duration or insulin sensitivity.

Conclusion: Our data shows that sleep intervention increased nightly sleep duration with longer stage 1, 2, and REM sleep, but no significant change in deep stage 3 sleep. These changes were linked with a positive impact on sleepiness. However, insulin sensitivity, a diabetes risk factor, was unchanged. Thus, different physiological systems may be impacted differently by sleep interventions.