Increased Risk of Ischemic Stroke in Amyotrophic Lateral Sclerosis: A Nationwide Cohort Study in South Korea

Abstract

Background: We investigated the risk of ischemic stroke in ALS and analyzed the effect of ALS-related physical disability using the Korean National Health Insurance Service database. Methods: A total of 2,252 ALS patients diagnosed between January 1, 2012, and December 31, 2015, and 1:10 age- and sex-matched control populations were included. After selection of cases that participated in the national health check-up programs, 659 ALS patients and 10,927 non-ALS participants were remained. Newly developing ischemic stroke as primary outcome was also defined by the ICD code and the incidence probability was assessed using by the Kaplan–Meier method during the follow-up duration. A Cox hazard regression model was used to examine the hazard ratios (HRs) for ischemic stroke in ALS after adjusting for potential confounders. Results: ALS patients were younger than the control group (60.3 ± 10.2 years vs. 61.4 ± 10.5 years, p = 0.008), and the proportion of male patients was similar between the two groups (61.0% vs. 62.5%, p = 0.447). ALS patients were more likely to have a lower body mass index (23.1 ± 2.92 vs. 24.0 ± 3.00, p < 0.001) and be non-drinkers (64.2% vs. 57.4%, p = 0.002) than the controls. In ALS patients, the incidence of ischemic stroke was 7.8 per 1,000 person-years, and the adjusted HR of ischemic stroke was 3.67 (95% confidence interval 2.02–6.67) compared with the control group. The risk of ischemic stroke did not differ by the presence of disability in ALS patients. Conclusions: Our findings suggest that ALS patients face increased risk of ischemic stroke compared with controls, but the risk did not differ by the presence of disability in ALS.