Inflammatory bowel disease is associated with increased stroke risk

A large national cohort study found that patients with inflammatory bowel disease (IBD) were 13% more likely than the general population to suffer a stroke, even decades after diagnosis.

The study included all biopsy-confirmed IBD patients in Sweden from 1969 to 2019, involving approximately 85,000 people. The incidence of stroke in these patients was 32.6 per 10,000 person-years compared with 27.7 in the matched control group (HR 1.13, 95% CI 1.08-1.17), according to the Karolinska Institutet in Stockholm. Dr. Jiangwei Sun and colleagues reported in the following paper. neurology.

The risk remains elevated 25 years after diagnosis, equivalent to one additional stroke per 93 people with IBD. “Our study is the largest study with the longest follow-up ever to investigate stroke risk in people with IBD,” the researchers wrote. “These findings highlight the need for clinical vigilance about long-term excess risk of cerebrovascular events in patients with IBD.”

The excess risk was primarily caused by ischemic stroke (HR 1.14, 95% CI 1.09-1.18) rather than hemorrhagic stroke (HR 1.06, 95% CI 0.97-1.15) and was significantly higher across IBD subtypes. The study showed an increased risk of 19% for Crohn’s disease (95% CI 1.10-1.29), 9% for ulcerative colitis (95% CI 1.04-1.16), and 22% for unclassified IBD (95% CI 1.08-1.08). 1.37). .

The researchers said that mechanisms underlying stroke risk in patients with IBD could include chronic systemic inflammation and alterations in the microbiota-gut-brain axis. Chronic inflammation induces endothelial dysfunction, promotes plaque formation and platelet activation and aggregation, contributing to atherosclerosis and arteriosclerosis, the researchers explained.

Furthermore, disruption of the microbiota–gut–brain axis is associated with neurodevelopmental disorders, neurodegenerative diseases, and stroke through a variety of processes, including regulated blood-brain barrier formation, myelination, microglial maturation, and neuroinflammation. Related. Finally, researchers noted that patients with IBD may be at increased risk of blood clots from surgery, fracture fixation, and steroid therapy.

This study found that women with IBD (HR 1.20, 95% CI 1.14-1.27) had a higher relative risk of stroke than men (HR 1.06, 95% CI 1.01-1.12). This may be explained by differences in risk factor profiles, sex hormone-dependent mechanisms, and stroke pathophysiology, the researchers said.

Sun et al. also reported a much higher relative risk of stroke in younger patients. The risk of developing IBD before age 17 was more than doubled (HR 2.35, 95% CI 1.52-3.62). Risk decreases gradually with age, suggesting that traditional cardiovascular risk factors are more prevalent in older patients and may outweigh the risks associated with IBD. In addition, more severe disease activity in patients with early-onset IBD may contribute to this trend, the study authors said.

“To prevent fatal CVD complications, screening and management of conventional stroke risk factors in IBD patients may be more urgent than in the general population,” the researchers explained.

In addition, “for individuals with traditional CVD risk factors, clinical response and remission, as well as endoscopic curative cardiovascular interventions to reduce undue risk of ischemic stroke,” Optimal anti-inflammatory therapy with fewer adverse effects should be encouraged,” Sun and co-authors said. the authors advised.

They identified patients with biopsy-confirmed IBD in the ESPRESSO (Epidemiology Enhanced by Swedish Histopathology Reports) cohort. The team also identified stroke patients and analyzed medical record data from the Swedish National Patient Registry. The researchers matched IBD patients with up to five randomly selected referees from the general population.

The primary outcome was the incidence of stroke overall. Secondary outcomes were ischemic stroke and hemorrhagic stroke. The researchers adjusted for factors such as hypertension, diabetes, obesity, dyslipidemia, chronic kidney disease, and chronic obstructive pulmonary disease to estimate hazard ratios using a flexible parametric survival model. The researchers also conducted an analysis comparing stroke risk in IBD patients with siblings without IBD to assess familial factors. Sun and co-authors said the sibling comparison supported their main findings.

The researchers said their study was limited by the lack of complete data on lifestyle factors that may contribute to stroke risk, such as smoking and alcohol consumption. Diagnostic criteria for IBD and stroke also changed during the study period, which may have affected the association. Furthermore, this study lacked information on inflammatory markers such as C-reactive protein. The researchers also noted that differences in the incidence and prevalence of IBD and stroke across countries, regions and ethnic groups, and the fact that the Swedish health care system offers universal access at “virtually free” He cautioned that the results may not be extrapolable to other situations. in charge. ”