0417 Objective, but Not Self-Reported Short Sleep Duration Increases Mortality Risk in Patients with Insomnia: The Wisconsin Sleep Cohort

Abstract Introduction Insomnia with objective, but not self-reported short sleep duration has been reported to be associated with cardiometabolic comorbidities. We aimed to investigate the association between insomnia with objective or self-reported and mortality in a general population sample. Methods From the Wisconsin Sleep Cohort 373 subjects with insomnia symptoms and 394 subjects without insomnia symptoms with a median follow-up duration of 8 years were included. Insomnia symptoms were defined as the presence of difficulty in falling sleep, maintaining sleep or early awakening for more than 5-15 times/month. Objective short sleep duration was defined as total sleep time < 6 hours based on polysomnography. Self-reported short sleep duration was defined as < 7.2 hours based on the median self-reported habitual sleep duration of the overall sample. Results Insomnia symptoms with objective short sleep duration were associated with a 2.6-fold higher risk of all-cause mortality (hazard ratio [HR]=2.57, 95% confidence interval [95%CI]=1.12-5.89) compared to subjects without insomnia symptoms and normal sleep duration (>6 hours) after controlling for confounders. Notably, this association was observed only in males (HR=3.77, 95% CI=1.19-11.97) but not in females. Furthermore, subjects with insomnia symptoms and normal sleep duration or with objective short sleep duration but without insomnia symptoms were not associated with increased risk of all-cause mortality. Finally, insomnia symptoms with self-reported short sleep duration were not associated with increased hazard of all-cause mortality. Conclusion Our findings support that insomnia with objective short sleep duration, which is about 50% of all insomnia patients, is the more severe insomnia phenotype. Objective short sleep duration appears to be an important marker of the biological severity of insomnia. Support (if any)