The Association between Insomnia and Increased Future Cardiovascular Events: A Nationwide Population-Based Study

Objectives Insomnia may increase the risk of cardiovascular disease (CVD), but the reported magnitude of the associations between sleep characteristics and CVD is inconsistent. We investigated the association between insomnia and the risk of developing acute myocardial infarction (AMI) and/or stroke by using a nationwide, population-based cohort database in Taiwan. Methods The analyses were conducted using information from a random sample of 1 million people enrolled in the nationally representative Taiwan National Health Insurance Research Database. A total of 44,080 individuals who were 20 years or older, including 22,040 people who had diagnosis of insomnia during the study period and an age-, sex-, comorbidity-matched group of 22,040 people without insomnia, were enrolled in our study. The study end points were the occurrence of cardiovascular events including AMI or stroke during follow-up. Results During a 10-year follow-up, 302 AMI events and 1049 stroke events were identified. The insomnia group had a higher incidence of AMI (2.25 versus 1.08 per 1000 person-years) and stroke (8.01 versus 3.69 per 1000 person-years, p <.001). Cox proportional hazard regression model analysis showed that insomnia was independently associated with a higher risk of future AMI (hazard ratio [HR] = 1.68, 95% confidence interval [CI] = 1.31-2.16, p <.001), stroke (HR = 1.85, 95% CI = 1.62-2.12, p <.001), and the composite event index (HR = 1.81, 95% CI = 1.61-2.05, p <.001), after adjusting for age, sex, and comorbidities. Conclusions Insomnia is associated with an increased risk of future cardiovascular events.