IBD tied to increased risk of rheumatoid arthritis

Patients with inflammatory bowel disease (IBD) appear to be at heightened risk of rheumatoid arthritis (RA), as reported in a study.

For the study, researchers used data from the UK Biobank, which involved adults between 37 and 73 years of age from 22 centres across England, Scotland, and Wales. They looked at patients who had IBD at baseline and excluded those with RA or missing follow-up information.

Cox regression proportional hazard models were used to estimate the risk of RA in relation to the presence of IBD. Mediation analysis was also conducted to evaluate the roles of C-reactive protein (CRP) and several composite inflammatory indices as potential mediators.

The analysis included a total of 373,693 individuals. Compared with individuals without IBD at baseline, those who had IBD had a twofold increased risk of developing RA (hazard ratio, 2.06, 95 percent confidence interval, 1.69–2.51). This association persisted despite controlling for multiple confounders and across all major subgroups.

Of note, the risk of RA associated with IBD was more pronounced among individuals with a low polygenic risk score for RA.

Mediation analysis indicated that systemic inflammatory markers, such as CRP, explained only a modest proportion of the association between IBD and RA. The highest mediation proportion observed was 9.56 percent.

More investigation is needed to gain insight into the mechanisms underlying the association between IBD and RA, as well as explore ways to improve long-term health outcomes in these patients.