Association between dipeptidyl peptidase-4 inhibitors and risk of bullous pemphigoid in patients with type 2 diabetes: A population-based cohort study

Aims: Higher bullous pemphigoid (BP) risk has been reported to be associated with dipeptidyl peptidase 4 inhibitor (DPP4i). The aim of this study is to examine the association between BP risk and DPP4i treatment. Methods: We conducted a nationwide cohort study based on the Taiwan National Health Insurance Database between 2000 and 2015. 124,619 diabetic patients who were receiving DPP4i therapy were matched 1: 1 with diabetic patients who had never received DPP4i by age, sex, duration of diabetes, insulin usage, and propensity score-matching of comorbidities. Results: The 6-year cumulative incidence of BP in the DPP4i-treated cohort was significantly higher than that in the non-DPP4i group (0.74 per 1000 vs 0.38 per 1000, P = 0.001). Modified Cox regression analysis revealed that DPP4i treatment (HR: 2.15, 95% CI: 1.18–3.91, P = 0.01), age (HR: 1.06, P < 0.001), renal disease (HR: 2.32, P < 0.001), and metformin user (HR: 1.93, P = 0.006) were associated with increased BP risk. Conclusions: DPP4i users had a 2.2-fold increase in the risk of BP, and the risk was the highest in those with concomitant use of DPP4i and insulin.