Sex disparity in stroke risk among patients with insomnia: a 19-year prospective cohort study.

ABSTRACT

STUDY OBJECTIVES: Considering the increased prevalence and more severe manifestations of insomnia among females along with established sex differences in ischemic stroke (IS) occurrence, this research aimed to examine the potential effects of the interaction between insomnia and sex on the incidence and outcome of IS. METHODS: We used data from the Korean Genome and Epidemiology Study (KoGES). The main exposure variables were insomnia history and sex. The main outcome was the occurrence of IS observed in biennial follow-up surveys. Cox proportional regression analysis was performed to estimate the effects of insomnia and sex on IS incidence. We also conducted interaction analysis to investigate the interaction effects between insomnia and sex on IS incidence. RESULTS: During 19 years of follow-up involving 8,933 individuals, we documented 370 cases of new-onset stroke (2.88 cases per 1,000 person-years). Cox proportional regression analysis showed that insomnia and female sex did not increase the risk of IS (HR 1.13 [95% CI 0.86-1.51] and HR 0.86 [95% CI 0.63-1.17], respectively). Interaction analysis demonstrated that stroke risk was increased only among females with insomnia (HR 1.34 [95% 1.05-1.80]) compared with those without insomnia. CONCLUSIONS: Our study highlights the significance of considering sex-specific factors when evaluating the relationship between insomnia and IS risk, particularly emphasizing the unique role of insomnia in IS risk among females.