Sleep duration and cardiovascular disease causal association: A two-sample Mendelian randomization study

An increasing number of studies have recently suggested a relationship between sleep duration and cardiovascular disease (CVD). However, a correlation between the two has not been studied. The aim of this study was to investigate a correlation between sleep duration and CVD. This study is based on summary data from genome-wide association studies (GWAS), across various races, regarding sleep duration and 12 major cardiovascular diseases. We utilized two-sample Mendelian randomization (MR), a method specifically designed to analyze correlation, to investigate whether sleep duration directly affects risk of developing CVD. Our primary analysis used the inverse variance weighting (IVW) method to examine the effect of sleep duration on multiple cardiovascular conditions. Additionally, we employed maximum likelihood, MR-Egger regression, weighted median, and weighted mode methods to ensure the robustness of our findings. This study revealed a correlation between over-sleeping and three cardiovascular conditions (valvular heart disease, myocardial infarction, and heart failure) with significant negative correlations (P < 0.05). No significant correlation was found with the remaining nine cardiovascular conditions (P > 0.05). Furthermore, we found that under-sleeping had a correlation with four cardiovascular conditions (non-ischemic cardiomyopathy, cardiac arrhythmias, valvular heart disease, and atrial fibrillation) with significant positive correlations (P < 0.05) butnot with the remaining eight cardiovascular conditions (P > 0.05). Over-sleeping was negatively correlated with several cardiovascular diseases, whereas under-sleeping was positively correlated with others, suggesting that lack of sleep may increase the risk of certain cardiovascular conditions.