Risk heterogeneity of bullous pemphigoid among dipeptidyl peptidase-4 inhibitors: A population-based cohort study using Japanese Latter-Stage Elderly Healthcare Database.

AIMS/INTRODUCTION: Although the association between dipeptidyl peptidase-4 (DPP-4) inhibitors and bullous pemphigoid (BP) has begun to be established, some studies have suggested there are risk differences among DPP-4 inhibitors. We conducted a population-based cohort study to examine the risk differences.

MATERIALS AND METHODS: Using the claims databases of the Fukuoka Prefecture Wide-Area Association of Latter-Stage Elderly Healthcare between April 1, 2013 and March 31, 2017, we conducted a retrospective cohort study to compare patients receiving one DPP-4 inhibitor with those who were prescribed another antidiabetic drug. The primary outcome was an adjusted hazard ratio (HR) of the development of bullous pemphigoid during a 3-year follow-up. The secondary outcome was the development of BP requiring systemic steroids immediately after the diagnosis. These were estimated using Cox proportional hazards regression models.

RESULTS: The study comprised 33,241 patients, of which 0.26% (n = 88) developed bullous pemphigoid during follow-up. The percentages of patients with bullous pemphigoid who required immediate systemic steroid treatment was 0.11% (n = 37). We analyzed four DPP-4 inhibitors: sitagliptin, vildagliptin, alogliptin, and linagliptin. Vildagliptin and linagliptin raised the risk of BP significantly (primary outcome, vildagliptin, HR 2.411 [95% confidence interval (CI) 1.325-4.387], linagliptin, HR 2.550 [95% CI 1.266-5.136], secondary outcome, vildagliptin HR 3.616 [95% CI 1.495-8.745], linagliptin HR 3.556 [95% CI 1.262-10.024]). A statistically significant risk elevation was not observed with sitagliptin and alogliptin (primary outcome, sitagliptin, HR 0.911 [95% CI 0.508-1.635], alogliptin, HR 1.600 [95% CI 0.714-3.584], secondary outcome, sitagliptin, HR 1.192 [95% CI 0.475-2.992], alogliptin, HR 2.007 [95% CI 0.571-7.053]).

CONCLUSIONS: Not all the DPP-4 inhibitors could induce bullous pemphigoid significantly. Therefore, the association warrants further investigations before generalization.