Purpose: Hypoandrogenism may have an association with urethral stricture. This study aimed to identify and quantify the association between testosterone levels and urethral stricture.
Materials and methods: A case-control study was conducted from January 2019 to January 2021. The case group included patients diagnosed with anterior urethral stricture who visited our urethral office of the urology department, while the control group included patients who visited our practice due to clinical conditions unrelated to voiding. In both groups, a 10 cc blood sample collection was scheduled between 7:30 and 9:30 a.m. The outcome was case/control status. The exposure variables were total testosterone, free testosterone, bioavailable testosterone, and hypoandrogenism (total testosterone < 300 ng/dL). The adjusted ORs were calculated for each exposure. Age, body mass index, hypertension, diabetes, smoking, and thyroxine levels were considered possible confounding factors.
Results: A total of 149 cases (mean age 59.5) were compared to 67 controls (64.3). Urethral stricture cases showed significantly lower mean total testosterone than controls (394 ng/dL vs 488 ng/dL). Similarly, the hypoandrogenism rate was significantly higher in the urethral stricture group (26% vs 7.5%). Each 100 unit increase in total testosterone was related to a 34% decrease in the odds of urethral stricture (adjusted OR 0.66, 95% CI: 0.51-0.86). Similarly, each increase of 1 unit of free testosterone and 10 units of bioavailable testosterone was associated with a decrease of 18% and 10%, respectively. A strong direct relationship was observed between hypoandrogenism and urethral stricture (adjusted OR 4.01, 95% CI: 1.37-11.7).
Conclusions: Our study demonstrates an independent association between hypoandrogenism and anterior urethral stricture.
Keywords: case-control studies; epidemiology; fibrosis; testosterone; urethral stricture.