(217) 5-alpha Reductase Inhibitors and Effects on Auditory System in Taiwan

Background: 5-alpha reductase inhibitors (5ARIs) are frequently used to manage benign prostatic hyperplasia, with clinical evidence backing their effectiveness and safety, thereby encouraging their widespread adoption and long-term use. Recent research indicated that 5ARIs may have impacts on the auditory system. However, the current findings were still inconsistent.

Objectives: To investigate the relationship between 5ARIs and the risk of auditory problems, including tinnitus and sudden sensorineural hearing loss.

Methods: This nationwide cohort study utilized data from the Taiwan National Health Insurance Database and employed a propensity score matching (PSM) strategy. The study group comprised 10,718 new users of 5ARIs, while 1,197,302 non-users were designated as the control group. The primary outcome was divided into two parts. The first part focused on the incidence of tinnitus during the 3-year follow-up period, and the second part examined the occurrence of sudden sensorineural hearing loss. All patients were followed until the event occurred, death, or the end of the follow-up period. PSM was employed to balance the differences in baseline characteristics and confounding factors such as comorbidities, aiming to reduce potential confounding effects. Cox proportional hazards models were used to calculate hazard ratios (HRs) for the risk of tinnitus and sudden sensorineural hearing loss between two groups.

Results: Concentrating on the incidence of tinnitus, an initial study involved 1,208,020 participants. After a 1:4 PSM process, 10,504 5ARI users and 42,010 non-users were identified and there was no significant difference in baseline characteristics and comorbidities between two groups. In the Cox proportional hazards regression model, after adjusting for confounders, 5ARI users exhibited a protective effect against the occurrence of tinnitus (HR=0.81, 95% CI=0.75-0.87). Focusing on the sudden sensorineural hearing loss, after a 1:4 matching process, 12,645 5ARI users and 47,794 non-users were identified. 5ARI users demonstrated a significantly lower risk of experiencing sudden sensorineural hearing loss (HR=0.67, 95% CI=0.520-0.88). These results remained consistent post-PSM (HR=0.737, 95% CI= 0.54-0.98).

Conclusions: This nationwide cohort study revealed a significant reduction in the risk of tinnitus and sudden sensorineural hearing loss among 5ARIs users compared to non-users.