Increased risk of ischaemic stroke among patients with multiple sclerosis

Background and purpose Inflammatory processes including autoimmune diseases which ignite endothelial dysfunction and atherosclerosis may promote development of cardiovascular diseases including ischaemic stroke. This study aimed to evaluate whether multiple sclerosis (MS) increases stroke risk. Methods A national insurance claim data set of 22 million enrollees in Taiwan was used to identify 1174 patients with MS and 4696 randomly selected age‐ and gender‐matched controls from 1 January 1997 to 31 December 2010. Both cohorts were followed up until the occurrence of stroke or censor. Relevant covariates, such as age, gender, hypertension, diabetes, hyperlipidaemia, coronary artery disease, congestive heart failure and pregnancy, were included for further survey. The hazard ratio (HR) of stroke was assessed using a Cox proportional hazards regression model. Results After adjusting for the relevant covariates, the MS cohort had an increased risk of stroke (adjusted HR = 12.1 for 1 year; adjusted HR = 4.69 for 2–5 years) compared with the control cohort within 5 years of follow‐up. Amongst participants without comorbidities, the MS cohort was still at a greater stroke risk than the control cohort [HR 4.93, 95% confidence interval (CI) 2.85–8.55]. Moreover, in the population aged ≤40, MS was associated with a significantly increased risk of stroke (HR 12.7, 95% CI 3.44–46.7). Conclusions Multiple sclerosis is declared to be associated with an increased risk in developing stroke, which requires closer attention to this group of patients for stroke prevention, especially in the younger population.