Excessive daytime sleepiness and vascular events: the Three City Study

Abstract

Objective: We assessed whether excessive daytime sleepiness (EDS) at baseline was associated with subsequent coronary heart disease (CHD) and stroke events.

Methods: The Three City Study, a French population-based multicenter prospective study, included 7,007 subjects aged ≥65 years with no personal history of CHD, stroke, or dementia, and self-rated EDS as never, rare, regular, or frequent in response to a face-to-face questionnaire. Hazard ratios (HRs) for the first episode of stroke and CHD over 6 years were estimated using a Cox proportional hazards model with age as the time scale.

Results: The mean age of the cohort was 73.7 years (standard deviation, 5.37), 63% were women, and 13.3% and 4.3% reported regular and frequent EDS, respectively. After a median follow-up period of 5.1 years, 372 subjects experienced a first event, either stroke (122 subjects) or a CHD event (250 subjects). The increased risk of CHD and stroke was confined to the group with frequent EDS, and was 1.73× as much as in the group that reported never having EDS (HR, 1.73; 95% confidence interval [CI], 1.15-2.60), after adjustment for confounding and mediating factors. This association was seen in those without hypertension but not in those with hypertension at baseline (p for interaction = 0.01). Moreover, the association with frequent EDS was statistically significant for stroke (HR, 2.10; 95% CI, 1.13-3.89) but not for CHD (HR, 1.51; 95% CI, 0.87-2.61).

Interpretation: The current study suggests that frequent EDS is independently associated with future vascular events and stroke in particular in healthy community-dwelling elderly subjects.