Sleep is vital to individual’s cardiovascular health. A handful of observational studies have suggested that both short (≤ 6 hours) and long (≥ 9 hours) sleep durations are associated with many cardiovascular diseases (CVDs). However, traditional observational studies, even they are well designed, prospective with large sample sizes, are prone to be biased by residual confounding effects and reverse causation. Therefore, the causal associations between sleep duration and CVDs remains unclear.

Research team from the Li Chiu Kong Family Sleep Assessment Unit, at the Department of Psychiatry, led by Professor Yun-Kwok Wing, performed a study entitled “Causal associations of short and long sleep durations with 12 cardiovascular diseases: linear and nonlinear Mendelian randomization analyses in UK Biobank”. In collaboration with several institutes, including Peking University, Sichuan University, etc, we employed linear and nonlinear Mendelian randomization (MR) analyses to investigate the causal associations of short and long sleep durations with 12 cardiovascular diseases in UK Biobank. We found that genetically predicted sleep duration was associated with arterial hypertension, atrial fibrillation, pulmonary embolism, and chronic ischaemic heart disease. Complementary analyses provided confirmative evidence of the adverse effects of genetically predicted short sleep duration on the risks of 5 out of the 12 CVDs, including arterial hypertension, pulmonary embolism, coronary artery disease, myocardial infarction, and chronic ischaemic heart disease. However, genetically predicted long sleep duration was not associated with any CVD. The findings of this study have significant implications in the prevention of CVDs. These results suggested that increasing sleep duration among those with short sleep duration may promote cardiovascular health for them, while simply reducing sleep per se is not likely to improve cardiovascular health in people with long sleep duration (Graphical Abstract).

This project was supported by the Impact Postdoctoral Fellowship Scheme of The Chinese University of Hong Kong.

These novel findings have been published in the European Heart Journal (Impact factor: 22.673; Rank: 2/138 in the field of CARDIAC & CARDIOVASCULAR SYSTEMS).

Graphical Abstract. Causal associations of short and long sleep durations with 12 cardiovascular diseases: linear and nonlinear Mendelian randomization analyses in UK Biobank.

Article in European Heart Journal
“Causal associations of short and long sleep durations with 12 cardiovascular diseases: linear and nonlinear Mendelian randomization analyses in UK Biobank” by Ai S, Zhang J, Zhao G, Wang N, Li G, So HC, Liu Y, Chau SW, Chen J, Tan X, Jia F, Tang X, Shi J, Lu L, Wing YK.
https://pubmed.ncbi.nlm.nih.gov/33822910/