Excessive daytime sleepiness is an independent risk indicator for cardiovascular mortality in community-dwelling elderly: the three city study

Abstract

Background and purpose: Excessive daytime sleepiness, one of the most frequent sleep complaints in the elderly, may affect survival, but inconsistent results have been observed in that population so far. We therefore estimated the risk of mortality for excessive daytime sleepiness (EDS) in community-dwelling elderly participating in the Three City Study.

Methods: The Three City Study is a French population-based multicenter prospective study including 9294 subjects (60% women) aged >or=65 years at recruitment between 1999 to 2001. At baseline, 8269 subjects rated EDS and nocturnal sleep complaints as never, rare, regular, and frequent in response to an administered questionnaire and provided information on medication use for sleep or anxiety. Hazard ratios (HR) of EDS (regular or frequent) for mortality over 6 years were estimated by a Cox proportional hazard model.

Results: At baseline, 18.7% of the study participants had regular or frequent EDS. After 6 years of follow-up, 762 subjects had died including 260 from cancer and 196 from cardiovascular disease. EDS was associated with a significant 33% increased risk of mortality (95% CI: 1.13 to 1.61) after adjustment for age, gender, study center, body mass index, previous cardiovascular disease, Mini Mental State Examination score, and cardiovascular risk factors. Further adjustment for current use of medication for sleep and for depressive symptoms slightly diminished the HRs. EDS was equally predictive of mortality in those who snored loudly and in those who did not. EDS was related to cardiovascular mortality but not to mortality attributable to cancer.

Conclusions: EDS might be independently associated with total and cardiovascular mortality in community-dwelling elderly.