Tadalafil use is associated with a lower incidence of Type 2 diabetes in men with benign prostatic hyperplasia: A population‐based cohort study

Abstract Background Tadalafil, commonly prescribed for benign prostatic hyperplasia (BPH), may benefit patients with Type 2 diabetes mellitus (T2DM) for glycemic markers and complications. However, the association between the long‐term use of tadalafil and the incidence of T2DM has not been investigated. Methods We emulated a target trial of tadalafil use (5 mg/day) and the risk of T2DM using a population‐based claims database in Japan. Patients who initiated tadalafil or alpha‐blockers for BPH and had no history of diabetes diagnosis, no dispensing of glucose‐lowering drugs, and no history of hemoglobin A1c levels of ≥6.5% (47–48 mmol/mol) were included. The primary outcome was the incidence of T2DM. Pooled logistic regression was used to estimate adjusted risk ratios (RRs) and 5‐year cumulative incidence differences (CIDs). Results A total of 5180 participants initiated tadalafil treatment and were compared with 20,049 patients who initiated alpha‐blockers. The median follow‐up time for each arm was 27.2 months (interquartile range [IQR], 12.0–47.9) in tadalafil users and 31.3 months (IQR, 13.7–57.2) in alpha‐blocker users. The incidence rates of T2DM in tadalafil and alpha‐blocker users were 5.4 (95% confidence interval [CI], 4.0–7.2) and 8.8 (95% CI, 7.8–9.8) per 1000‐person years, respectively. Initiation of tadalafil was associated with a reduced risk of T2DM (RR, 0.47; 95% CI, 0.39–0.62; 5‐year CID, −0.031; 95% CI, −0.040 to −0.019). Conclusion The incidence of T2DM was lower in men with BPH treated with tadalafil than in those treated with alpha‐blockers. Thus, tadalafil may be more beneficial than alpha‐blockers in preventing T2DM.