0539 Are Short Sleepers Uncoupled Sleepers?

Abstract

Abstract Introduction While short sleep durations (<7h/night) are associated with increased diabetes risk, there is limited evidence that increasing the habitual sleep duration of short sleepers is either feasible, or will reliably improve metabolic health outcomes. Furthermore, in the absence of insomnia disorder, it remains unclear whether habitual short sleep mainly reflects a genetic predisposition or a lifestyle choice. In a randomized controlled study we delivered a sleep extension protocol based on CBTi principles to overweight ‘short sleepers’ at increased risk of Type II diabetes. Methods 18 male short sleepers (Mage=41.4; MBMI=29.57; baseline mean TST=5.8 h/ night) with no complaints of insomnia were randomized to the sleep extension intervention or control condition (printed sleep hygiene advice). The 6-week intervention commenced with personalized sleep re-scheduling negotiated in a 60-minute 1-to-1 session, and supported by elements of sleep hygiene, stimulus control, relaxation and cognitive strategies. Outcomes included sleep duration (actigraphy), fasting insulin, Mean Amplitude of Glycemic Excursions (MAGE) from continuous glucose monitoring, and blood pressure. Data were analyzed in linear fixed effects models including time, group and baselines values. Results Adherence to the 6-week protocol was high. Relative to controls (n=8), intervention participants (n = 10) showed a significant increase in TST (95%CI 46.91min, 101.64min, p<0.001; MDiff = 79.4min, p<0.001) and significant reductions in fasting insulin (95%CI -32.08 pmol/L, -.97.0 pmol/L; p=0.04; MDiff = -10.2 pmol/L, p=0.06); MAGE (95%CI -0.77, -0.08, p=0.02; MDiff -0.35, p=0.05) and diastolic (95%CI -22, -5, p=0.004; MDiff=-12, p=0.004); and systolic blood pressure (95%CI -20, -2, p=0.03; MDiff=-10, p=0.006). Conclusion CBTi-based sleep extension protocols offer feasible and effective lifestyle interventions in the management of metabolic health in overweight short sleepers who fit published categorization of non-complaining poor sleepers with an undeveloped insomnia identity whose subjective sleep experience and objective sleep characteristics are ‘uncoupled’. Support School of Sport, Exercise and Health Sciences, Loughborough University