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 2,251 ALS patients diagnosed between January 1, 2012, and December 31, 2015, and 1:10 age- and sex-matched control populations were included. Cases that participated in the national health check-up programs were selected. A Cox hazard regression model was used to examine the hazard ratios (HRs) for ischemic stroke in ALS after adjusting for potential confounders. Results A total of 681 ALS patients and 10,934 non-ALS participants were selected. ALS patients were slightly younger than the control group (60.3 +/- 10.1 years vs. 61.0 +/- 10.5 years, p = 0.105), and the proportion of male patients was similar between the two groups (61.6% vs. 60.9%, p = 0.722). ALS patients were more likely to have a lower body mass index (23.1 +/- 2.92 vs. 24.0 +/- 3.1, p < 0.001) and obstructive sleep apnea syndrome (0.59% vs. 0.06%, p < 0.001) than the controls. In ALS patients, the incidence rate of ischemic stroke was 6.32 per 1,000 person-years, and the adjusted HR of ischemic stroke was 2.58 (95% confidence interval 1.38 - 4.82) compared with the matched group. The risk of ischemic stroke did not differ by the presence of disability in ALS patients. Conclusions Our findings suggest that ALS patients have an increased risk of ischemic stroke compared with controls, but the risk did not differ by the presence of disability in ALS.