Insomnia and Coronary Artery Diseases: A Mendelian Randomisation Study

Abstract Objective: Observational studies indicate that insomnia may increase the risk of developing and/or dying from cardiovascular diseases, especially coronary artery disease (CAD). Our purpose is to explore the underlying causal relationship between genetic variants susceptible to insomnia and the risk of CAD by Mendelian randomization analysis. Methods: The study was conducted using publicly available statistical data on genetic variants identified from a genome-wide association meta-analysis of insomnia (n = 113,006 individuals) and a genome-wide association meta-analysis of CAD (n = 184,305 individuals), which consisted of both cases and non-cases. The genetic association between variants and CAD was assessed by the variants’ association with insomnia, and estimations were integrated by an inverse-variance weighted meta-analysis. Results: Among the Mendelian randomized analytical sample, 8 variants were associated with insomnia complaints and CAD. And there was no pleiotropic association with the latent confounders. In addition, in the inverse-variance weighted meta-analysis (the estimations combined from the 8 variants), the odds ratio was 1.15 (95% CI: 1.05–1.25; P = 0.002) for CAD, and in the weighted method analysis, the odds ratio was 1.14 (95% CI: 1.03–1.27; P = 0.015) for CAD. Conclusions: All of the data indicated that some valuable variants might involve in the development of CAD by leading the insomnia. Therefore, insomnia might be a causal factor for CAD, and improving the quality of sleep might be a new way for populations with insomnia to prevent CAD.