IBD increases long-term stroke risk, study finds

Patients with inflammatory bowel disease (IBD) are at higher risk for stroke for up to 25 years after diagnosis, a recent study found.

Researchers in Sweden analyzed a cohort of 85,006 patients with biopsy-confirmed IBD between 1969 and 2019. Overall, 25,257 had Crohn's disease, 47,354 had ulcerative colitis, and 12,395 had unclassified IBD. They matched patients with IBD with up to five controls (n=406,987) and with their full siblings who did not have IBD (n=101,082). The study's primary outcome was incident overall stroke; ischemic stroke and hemorrhagic stroke were secondary outcomes. The results were published June 14 by Neurology.

There were 3,720 incident strokes in patients with IBD and 15,599 in matched controls (incidence rate [IR], 32.6 vs. 27.7 per 10,000 person-years; adjusted hazard ratio [HR], 1.13 [95% CI, 1.08 to 1.17]). The adjusted HR remained higher for patients with IBD 25 years after diagnosis, with an estimated one additional stroke case per 93 patients with IBD until then, the authors said. Ischemic stroke was the main driver of increased risk, with an adjusted HR of 1.14 (95% CI, 1.09 to 1.18) compared with hemorrhagic stroke (adjusted HR, 1.06; 95% CI, 0.97 to 1.15).

Incidence of ischemic stroke across IBD subtypes versus matched controls was 23.3 versus 19.2 per 10,000 person-years for Crohn's disease (adjusted HR, 1.19; 95% CI, 1.10 to 1.29), 25.7 versus 22.6 per 10,000 person-years for ulcerative colitis (adjusted HR, 1.09; 95% CI, 1.04 to 1.16), and 30.5 versus 22.8 per 10,000 person-years for unclassified IBD (adjusted HR, 1.22; 95% CI, 1.08 to 1.37). Results were similar when comparing patients with IBD to their siblings. The adjusted HR for overall stroke was higher in women than in men (1.20 [95% CI, 1.14 to 1.27] vs. 1.06 [95% CI, 1.01 to 1.12]; P<0.0001 for interaction) and in those diagnosed with IBD during childhood (adjusted HR, 2.35; 95% CI, 1.52 to 3.62) or at ages 18 years to younger than 40 years (adjusted HR, 1.31; 95% CI, 1.17 to 1.48).

The authors noted that some of the matched controls could have had undiagnosed stroke and that diagnostic criteria for IBD and stroke have changed over time, among other limitations. They concluded that patients with IBD are at higher risk for stroke over the long term, especially ischemic stroke, and that this risk appears especially pronounced in women and in those diagnosed with IBD at a younger age. “These findings seem to be independent of familial factors and highlight the need for clinical vigilance about the long-term excess risk of cerebrovascular events in IBD patients,” the authors wrote. They called for more urgent screening and management of traditional stroke risk factors in IBD patients, optimal medical therapy in those with traditional risk factors for cardiovascular disease, and the development of guidelines on assessment and management of cardiovascular disease risk in patients with IBD.