Sleep disorders and increased risk of subsequent acute coronary syndrome in individuals without sleep apnea: A nationwide population-based cohort study

Objectives: Studies investigating the relationship between nonapnea sleep disorders and the risk of acute coronary syndrome (ACS) are scant. This study evaluated whether the risk of ACS is associated with sleep disorders other than sleep apnea in Taiwan. Methods: This longitudinal nationwide population-based cohort study investigated the incidence and risk of ACS in 49,099 cases of nonapnea sleep disorders newly diagnosed from January 1997 to December 2001. In total, 98,198 control participants without sleep disorders were randomly selected, frequency matched by age and sex from the general population. The follow-up period started from the date of entering the study cohort to the date of an ACS event, censoring, or December 31, 2010. We conducted Cox proportional hazard regression analysis to estimate the effects of nonapnea sleep disorders on ACS risk. Results: The nonapnea sleep disorder cohort had an adjusted hazard ratio (HR; 95% confidence interval [CI] = 1.29-1.60) of subsequent ACS 1.43-fold higher than that of the cohort without sleep disorders. The highest crude effect of nonapnea sleep disorders on ACS incidence was detected among young adults. However, by adjusting for probable risk factors, the HR of ACS increased with age. Compared with women, men had an adjusted HR of 1.57 (95% CI = 1.42-1.75). Hypertension, diabetes mellitus (DM), and hyperlipidemia were also significant factors associated with the increased risk of ACS. Conclusion: This nationwide population-based cohort study provides evidence that patients with nonapnea sleep disorders are at higher risk of developing acute coronary syndrome, which increases with age.