# Cardiovascular safety of 5α-reductase inhibitors in people with benign prostatic hyperplasia and type 2 diabetes: a propensity score-matched analysis

## TL;DR

This study found that 5α-reductase inhibitors may increase the risk of major heart events in people with diabetes and an enlarged prostate.

## Contribution

The study provides new evidence on the cardiovascular risks of 5α-reductase inhibitors in patients with type 2 diabetes and BPH.

## Key findings

- 5α-reductase inhibitors were linked to a higher risk of major adverse cardiovascular events compared to tamsulosin.
- The increased risk was primarily due to a higher incidence of myocardial infarction.
- No increased risk was observed for stroke or cardiovascular death.

## Abstract

5α-Reductase inhibitors are prescribed for the treatment of benign prostatic hyperplasia (BPH) and their use is associated with increased risk of incident type 2 diabetes. This study assessed the long-term cardiovascular safety of 5α-reductase inhibitors in comparison with tamsulosin in people with co-existing BPH and type 2 diabetes.

We performed a retrospective, population-based cohort study using Scottish Diabetes Research Network National Diabetes Dataset (SDRN-NDS) and IQVIA Medical Research Data (IMRD-UK). BPH patients ≥40 years with recorded type 2 diabetes mellitus and ≥2 prescriptions of 5α-reductase inhibitors or tamsulosin (2006–2021) were included. After 1:2 variable ratio propensity score matching, cause-specific Cox proportional-hazard models were used to compute the hazard ratio (HR) of incident major adverse cardiovascular events (MACE). A total of 11 969 patients were included in SDRN-NDS and 16 492 in IMRD-UK, with median follow-up durations of 3.8 (IQR: 1.7–6.8) and 4.8 (2.0–8.3) years, respectively. In SDRN-NDS, the HR of MACE in patients receiving 5α-reductase inhibitors relative to tamsulosin was 1.15 (95% CI 1.03–1.30, P = 0.007), driven by increased risk of myocardial infarction (MI) (HR 1.20, 1.03–1.40, P = 0.022). This was replicated in IMRD-UK, where HR was 1.26 (1.07–1.47, P = 0.008) for MACE and 1.33 (1.10–1.60, P = 0.005) for MI. We did not observe any increased risks in stroke, cardiovascular death, microvascular complications of diabetes, or faster progression to insulin-based therapies.

Our retrospective data from two large cohorts suggest that the risk of MACE may be increased among patients with type 2 diabetes taking 5α-reductase inhibitors, potentially driven by increased risk of MI. This supports careful monitoring of macrovascular outcomes when prescribing 5α-reductase inhibitors in this population.

Graphical Abstract