A number of studies have demonstrated an association between sleep duration and all-cause mortality. Data are inconsistent however regarding sleep duration and cause specific mortality. This study assessed the association between self-reported sleep duration and the risks of fatal coronary heart disease, sudden cardiac death, cancer-related death and all-cause mortality.
METHODSA representative sample of men, 42 to 61 years of age at baseline, all living in eastern Finland, were studied. Data collected at baseline, occurring between 1984 and 1989, included self-reported sleep duration, tobacco abuse, resting blood pressure, alcohol consumption, body mass index, blood sugar history and blood levels of lipids, lipoproteins, creatinine, C-reactive protein and glucose. The subjects were followed for all-cause coronary heart disease and cancer related deaths occurringby the year 2014.
RESULTSAt baseline, the mean age of the participants was 51.7 years, with an average sleep duration of 9.1 hours. During a median of 25.9 years′ followup, of the 3, 261 participants, 802 deaths occurred. Those in the top quartile of sleep duration, with at least 10.2 hours of sleep per night (a median of 11.5 hours), had a significantly increased risk of allcause mortality (P<0.001), as compared to those who slept less than eight hours (HR 1.36). This increased risk was noted for coronary heart disease (HR 1.56), sudden cardiac death (HR 1.47) and cancer death (HR 1.39). In the fully adjusted analysis, which included known risk factors, the associations were attenuated, but persisted.
CONCLUSIONThis longitudinal study of middle-aged men found that sleeping more than 10 hours per night is associated with a significantly increased risk of all-cause mortality.