Sleep quality and risk of coronary heart disease - a prospective cohort study from the English longitudinal study of ageing.

BACKGROUND

The association between sleep quality and risk of coronary heart disease (CHD) remains unclear in the elderly.

RESULTS

At eight-year follow up, a total of 411 (4.29%) participants developed CHD. Compared with good quality group, the multivariable hazard ratio [HR] (95% confidence interval [CI]) for CHD was 1.393 (1.005, 1.931) for intermediate quality group and 1.913 (1.206, 3.035) for poor quality group. Consistent results were observed in participants with normal sleep duration.

CONCLUSIONS

Poor sleep quality may be a novel modifiable risk factor for CHD in the elderly independent of conventional cardiovascular risk factors, even when sleep duration was normal.

METHODS

The current study included 9570 CHD-free participants in the English Longitudinal Study of Ageing (ELSA) from wave 4 (2008 to 2009). Incident CHD included new onset angina or myocardial infarction. Sleep quality was measured by a four-item questionnaire. Score ranged from 1 (best) to 4 (poorest). Participants were divided into three groups: good quality (1 ≤ score <2), intermediate quality (2 ≤ score <3) and poor quality (3 ≤ score ≤4). Cox regression model was used to calculate HR for CHD risk according to sleep quality, adjusted for conventional CHD risk factors and sleep duration.