Correlations between sleep patterns and cardiovascular diseases in a Chinese middle-aged population.

Epidemiological and animal studies have suggested an association between habitual sleep patterns and cardiovascular (CV) disease, but the results are still controversial. Therefore, the aims of this study are to investigate the relationships between habitual sleep patterns and CV disease based on Prospective Urban Rural Epidemiology (PURE) China study. PURE China study recruited 46 285 participants, aged 35-70, from 12 provinces and 115 communities in China. Habitual sleep patterns and CV disease were self-reported. Multilevel logistic regression was used in our analysis. In this study, 39 515 participants were eligible in our analysis, including 23 345 (59.1%) women and 16 170 (40.9%) men. Sleeping ≥9 h per day was associated with increased odds of CV disease (OR = 1.16, 95% CI: 1.01-1.32, p = 0.033) compared with sleeping 7-8 h per day. Taking daytime naps was also associated with an increased odds of CV disease, and the CV odds increased with increasing napping duration (p for trend < 0.001). For the sleeping < 6 h per day, we only found an association with coronary artery disease (CAD) (OR = 1.58, 95% CI: 1.01-2.48, p = 0.046). Participants with only 7-8 h sleep per night had lowest prevalence of CV disease (OR = 0.77, 95% CI: 0.65-0.90, p = 0.001) compared with other sleep patterns. Napping, long and short duration of habitual sleep may increase the odds of CV disease. Only participants sleeping 7-8 hours at night are recommended in this study, and large longitudinal studies are needed to confirm these results.