Assessing the Association Between Dipeptidyl Peptidase 4 Inhibitor Use and Inflammatory Bowel Disease Through Drug Adverse Event Reporting

Dipeptidyl peptidase-4 inhibitor-induced autoimmune diseases: Current evidence

Dipeptidyl peptidase-4 inhibitors (DPP-4i) have an important place in the management of type 2 diabetes. The DPP-4 enzyme is ubiquitously distributed throughout the human body and has multiple substrates through which it regulates several important physiological functions. DPP-4 regulates several immune functions, including T-cell activation, macrophage function, and secretion of cytokines. Studies have reported an increase in autoimmune diseases like bullous pemphigoid, inflammatory bowel disease, and arthritis with DPP-4i use. The relationship of DPP-4i and autoimmune diseases is a complex one and warrants further research into the effect of DPP-4 inhibition on the immune system to understand the pathogenesis more clearly. Whether a particular cluster of autoimmune diseases is associated with DPP-4i use remains an important contentious issue. Nevertheless, a heightened awareness from the clinicians is required to identify and treat any such diseases. Through this review, we explore the clinical and pathophysiological characteristics of this association in light of recent evidence.

Dipeptidyl peptidase 4 inhibitors and their potential immune modulatory functions

Dipeptidyl peptidase 4 (DPP4) inhibitors (DPP4is) are oral anti-diabetic drugs (OADs) for the treatment of type 2 diabetes mellitus (T2DM) through inhibiting the degradation of incretin peptides. Numerous investigations have been focused on the effects of DPP4is on glucose homeostasis. However, there are limited evidences demonstrating their Potential modulatory functions in the immune system. DPP4, originally known as the lymphocyte cell surface protein CD26, is widely expressed in many types of immune cells including CD4(+) and CD8(+) T cells, B cells, NK cells, dendritic cells, and macrophages; and regulate the functions of these cells. In addition, DPP4 is capable of modulating plenty of cytokines, chemokines and peptide hormones. Accordingly, DPP4/CD26 is speculated to be involved in various immune/inflammatory diseases and DPP4is may become a new drug class applied in these diseases. This review focuses on the regulatory effects of DPP4is on immune functions and their possible underlying mechanisms. Further clinical studies will be necessitated to fully evaluate the administration of DPP4is in diabetic patients with or without immune diseases.

Dipeptidyl Peptidase 4 Inhibitors and Risk of Inflammatory Bowel Disease: Real-world Evidence in U.S. Adults

OBJECTIVE

A recent study raises concerns that dipeptidyl peptidase 4 inhibitors (DPP4i) are associated with increased risk of inflammatory bowel disease (IBD). We evaluated the association between new use of DPP4i and IBD risk compared with other second-line antihyperglycemics.

RESEARCH DESIGN AND METHODS

We implemented an active-comparator, new-user cohort design using two U.S. administrative claims databases for commercially insured (MarketScan) and older adult (Medicare fee-for-service, 20% random sample) patients from January 2007 to December 2016. We identified patients, aged ≥18 years, who initiated DPP4i versus sulfonylureas (SUs) or initiated DPP4i versus thiazolidinediones (TZDs) and were without prior diagnosis, treatment, or procedure for IBD. The primary outcome was incident IBD, defined by IBD diagnosis preceded by colonoscopy and biopsy and followed by IBD treatment. We performed propensity score weighting to control for measured baseline confounding, estimated adjusted hazard ratios (aHRs [95% CI]) using weighted Cox proportional hazards models, and used random-effects meta-analysis models to pool aHRs across cohorts.

RESULTS

We identified 895,747 eligible patients initiating DPP4i, SU, or TZD; IBD incidence rates ranged from 11.6 to 32.3/100,000 person-years. Over a median treatment duration of 1.09-1.69 years, DPP4i were not associated with increased IBD risk across comparisons. The pooled aHRs for IBD were 0.82 (95% CI 0.41-1.61) when comparing DPP4i (n = 161,612) to SU (n = 310,550) and 0.76 (0.46-1.26) when comparing DPP4i (n = 205,570) to TZD (n = 87,543).

CONCLUSIONS

Our population-based cohort study of U.S. adults with diabetes suggests that short-term DPP4i treatment does not increase IBD risk.