Diabetes and the risk of infections with immunomodulator therapy in inflammatory bowel diseases

Abstract

Infections are an important concern in patients using immunosuppressive therapy for their inflammatory bowel disease (IBD). Diabetes affects nearly 10% of Americans. Whether it confers an additional risk with immunosuppression in IBD has not been examined previously. To examine the association between diabetes and infections with immunomodulator use in IBD METHODS: Using a validated, multi-institutional IBD cohort, we identified all patients who received at least one prescription for immunomodulators (thiopurines, methotrexate). Our primary outcome was infection within 1year of the prescription of the immunomodulator. Multivariable logistic regression adjusting for relevant confounders was used to estimate the independent association with diabetes. Our study included 2766 patients receiving at least one prescription for immunomodulators among whom 210 (8%) developed an infection within 1year. Patients who developed an infection were likely to be older, have more comorbidities, more likely to have received a prescription for steroids but similar in initiation of anti-TNF therapy within that year. Only 8% of those without an infection had diabetes compared to 19% of those who developed an infection within 1year [odds ratio (OR) 2.74, 95% confidence interval (CI) 1.88-3.98, P<0.001]. On multivariate analysis, diabetes was independently associated with a nearly two-fold increase in risk of infections (OR: 1.80, 95% CI: 1.20-2.68). There was no increase in risk of infections with addition of anti-TNF therapy (OR: 1.14, 95% CI: 0.80-1.63). Diabetes is an independent risk factor for infection in IBD patients using immunomodulator therapy.