Abstract
The risk of psoriasis in diabetic patients has rarely been explored. This study aims to compare the risk of incident psoriasis in patients with Type 2 diabetes (T2D) who initiate dipeptidyl peptidase-4 inhibitors (DPP-4is) or thiazolidinediones (TZDs) with those who initiate sulfonylureas, the most common second-line glucose-lowering therapy, in addition to metformin monotherapy. This sequential, propensity-score-matched, new-user comparative effectiveness study utilized a target trial emulation framework. It included adults with T2D receiving metformin monotherapy, using data from 2006 to 2015 from a general population database in Taiwan. The primary outcome was the incidence of psoriasis, determined through diagnoses recorded in urgent care, hospital, and outpatient department records. Cox proportional hazards and Poisson regressions with 1:4 propensity score matching was employed to evaluate the risk factors for psoriasis after adjusting for comorbidities and the use of other medications. In 49,810 propensity score-matched adults with T2D (27,630 men [55.4%]; mean age 57.5 years) identified in the database, the incidence rate of psoriasis in DPP-4i users was 188 cases per 100,000 person-years, lower than in sulfonylurea users (467 cases per 100,000 person-years), with a hazard ratio(HR) of 0.422 (95% CI, 0.273-0.716). For the TZD vs. sulfonylurea comparison, the HR was 0.35, but the smaller matched dataset resulted in wide confidence intervals. The findings suggest that the use of DPP-4is is associated with a lower risk of psoriasis compared to sulfonylureas in patients with T2D. These results can guide the selection of glucose-lowering therapies in T2D patients who are at risk of developing psoriasis.