Scientists found an association between inflammatory bowel disease and a long-term increased risk of ischemic stroke.
In a study published on June 14 in the online issue of Neurology, the medical journal of the American Academy of Neurology, scientists identified all people in Sweden between 1969 and 2019 with a biopsy-confirmed inflammatory bowel disease (IBD) diagnosis. The participants included had a diagnosis of Crohn's disease, ulcerative colitis, or unclassified IBD.
The team matched these participants to their IBD-free siblings and individuals from the general public without IBD. In total, 85,006 people with IBD, 406,987 matched reference individuals, and 101,082 IBD-free siblings were included in the analysis.
After an average 12-year follow-up, the researchers found that 3,720 people with IBD experienced strokes, which is a stroke incidence rate of 32.6 per 10,000 person-years. In contrast, strokes occurred in 15,599 reference individuals, with a rate of 27.7 per 10,000 person-years.
Person-years represent the number of participants and the length of time each individual remains in the study.
When the scientists looked at siblings, they found that people with IBD had an 11% higher risk of stroke than their non-IBD brothers and sisters.
In addition, after accounting for other stroke risk factors, including obesity, heart disease, and high blood pressure, the research team found that individuals with IBD were 13% more likely to have a stroke up to 25 years after IBD diagnosis than people without the condition.
The study authors note that this elevated risk was primarily associated with ischemic rather than hemorrhagic stroke.
The team also found that the risk level differed across IBD subtypes. For example, people with Crohn's disease had a 19% increased risk of stroke, while those with ulcerative colitis had a 9% increased risk. People with unclassified IBD seemed to have the highest chance, with a risk increase of 22%.
However, the criteria for diagnosing IBD have changed over the years, which may have impacted the study results. In addition, the scientists did not account for lifestyle factors that could impact stroke risk, such as alcohol use, smoking, and diet, which could also affect the results.
Still, in a news release, study author Jiangwei Sun, Ph.D., of the Karolinska Institutet in Stockholm, Sweden, says, "These results show that people with inflammatory bowel disease and their doctors should be aware of this long-term increased risk. Screening and management of stroke risk factors may be more urgent in people with IBD."