Metformin not protective against older-onset IBD

The use of metformin does not appear to confer any benefits in terms of reducing the risk of older-onset inflammatory bowel disease (IBD), a study has found.

Researchers used data from a Danish nationwide population-based cohort and conducted a nested case–control study using a new-user active comparator design. They matched 10 individuals without IBD for each IBD patient based on age, sex, and duration of follow-up.

Conditional logistic regression was used to analyse the association between metformin exposure and older-onset IBD risk. Factors such as educational level, other immune-mediated inflammatory diseases, and use of dipeptidyl peptidase (DPP)-4 inhibitors and statins were included in the analysis as potential confounders.

A total of 302,863 individuals who were IBD free and were new users of oral glucose-lowering drugs were identified. Of these, 1,271 individuals developed IBD and were matched to 12,676 matched non-IBD controls. The mean age at IBD diagnosis was 66 years.

Ever use of metformin showed no association with the risk of IBD (adjusted odds ratio [OR], 0.95, 95 percent confidence interval [CI], 0.78–1.15) and its subtypes, Crohn’s disease (adjusted OR, 0.87, 95 percent CI, 0.60–1.26) and ulcerative colitis (adjusted OR, 1.04, 95 percent CI, 0.83–1.31).

Likewise, the cumulative dose of metformin or the treatment duration with metformin had a null effect on risk of IBD.

The findings suggest that metformin is not protective against the risk of older-onset IBD despite the drug’s known anti-inflammatory effects and notable impact on the gut microbiome.