Constipation associated with higher stroke risk

A meta-analysis found a statistically significant association between constipation and elevated stroke risk.

Researchers conducted a systematic review and meta-analysis, using eight studies comprising 5,360,573 patients to compare the incidence of stroke between those with and without constipation. Mean patient age was 53.9 years, and 65% were men. Results were published by the Journal of Clinical Gastroenterology on Dec. 23, 2024.

Patients with constipation had a significantly increased risk of stroke, with a pooled risk ratio of 1.41 (95% CI, 1.13 to 1.75; P<0.01) compared to patients without constipation. When specific types of stroke were analyzed, constipation was associated with a significantly increased risk of ischemic stroke with a pooled risk ratio of 1.50 (95% CI, 1.15 to 1.96; P<0.01), but not for the mixed-type stroke outcome (pooled RR, 1.31 [95% CI, 0.81 to 2.12]; P=0.27). Sensitivity analysis based on the average age of the study population removed one study, and the remaining results were not statistically significant (pooled RR of 1.02 [95% CI, 0.92 to 1.14]; P<0.001)]. A funnel plot suggested no publication bias, which was supported by a regression test.

Potential mechanisms that might explain the relationship between constipation and stroke include alterations in the brain-gut axis, imbalance of gut microbiota, serum levels of modulating inflammatory cytokines, and age, as well as transient events during constipation such as straining, defecation syncope, and serotonin involvement, according to the study authors.

“This finding highlights the potential importance of considering gastrointestinal health in cardiovascular risk assessment,” they wrote. “However, further research is needed to elucidate the underlying mechanisms and to determine whether this association represents a causal relationship or reflects shared risk factors.”