Objective: The potential use of testosterone preparations for substitution therapy for ageing men and for male contraception, in addition to the well established substitution therapy of male hypogonadism, make increased testosterone use likely. However, little clinical information is available on the effect of testosterone therapy on the prostate in hypogonadal men.
Design and measurements: In a controlled cross-sectional study, prostate volume measured by transrectal ultrasonography, serum levels of prostate-specific antigen (PSA) and sex hormones, and uroflow parameters were determined.
Patients: Three groups of age-matched men were enrolled in the study: 47 newly diagnosed hypogonadal men before testosterone treatment, 78 hypogonadal men with at least 6 months of effective testosterone therapy and 75 normal men.
Results: Regression analysis revealed a significant positive correlation of prostate volume with age in normal men and testosterone-treated hypogonadal men, whereas no significant correlation was detected in untreated hypogonadal men. Prostate volume was significantly lower in untreated hypogonadal men (12.2 (11.0-13.5) ml) (mean (95% confidence limits)) compared to both other groups. However, no significant difference in prostate volume was detected between testosterone-treated hypogonadal men (21.3 (19.9-22.8) ml) and normal men (22.9 (21.4-24.4) ml). Similar results were obtained for PSA with comparable values in the testosterone-treated hypogonadal men (0.98 (0.88-1.10) micrograms/l) and normal men (1.02(0.91-1.14) micrograms/l), and significantly lower concentrations in the untreated hypogonadal men (0.64 (0.55-0.73) micrograms/l). No differences in uroflow parameters were detected between the three study groups.
Conclusions: Effective testosterone treatment of hypogonadal men results in prostate volume and prostate-specific antigen levels comparable to age-matched normal men. Therefore, testosterone-induced prostate growth should not preclude hypogonadal men from testosterone substitution therapy.