Co-morbid insomnia and obstructive sleep apnoea is associated with all-cause mortality

Abstract

Study ObjectivesIncreased mortality has been reported in people with insomnia and in those with obstructive sleep apnoea (OSA). However, these conditions commonly co-occur and the combined effect of co-morbid insomnia and sleep apnoea (COMISA) on mortality risk is unknown. This study used Sleep Heart Health Study (SHHS) data to assess associations between COMISA and all-cause mortality risk.MethodsInsomnia was defined as difficulties falling asleep, maintaining sleep, and/or early morning awakenings from sleep ≥16 times a month and daytime impairment. OSA was defined as an apnoea-hypopnoea index ≥15 events/h sleep. COMISA was defined if both conditions were present. Multivariable adjusted Cox proportional hazard models were used to determine the association between COMISA and all-cause mortality (n=1210) over 15 years of follow-up.Results5236 participants were included. 2708 (52%) did not have insomnia/OSA (control), 170 (3%) had insomnia-alone, 2221 (42%) had OSA-alone, and 137 (3%) had COMISA. COMISA participants had a higher prevalence of hypertension (ORs [95%CI]; 2.00 [1.39, 2.90]) and cardiovascular disease compared to controls (1.70 [1.11, 2.61]). Insomnia-alone and OSA-alone were associated with higher risk of hypertension but not cardiovascular disease compared to controls. Compared to controls, COMISA was associated with a 47% (HR, 95% CI; 1.47 (1.06, 2.07)) increased risk of mortality. The association between COMISA and mortality was consistent across multiple definitions of OSA and insomnia.ConclusionsCo-morbid insomnia and sleep apnoea was associated with higher rates of hypertension and cardiovascular disease at baseline, and an increased risk of all-cause mortality compared to no insomnia/OSA.