To evaluate the relationship between serum testosterone levels and measures of benign prostatic hyperplasia (BPH) in the aging male population of Taiwan. Previous studies of the associations of serum testosterone levels and measures of BPH have not been consistently reported and have focused on a predominately white population.

A free health screening for aging men (45 years old or older) was conducted in Kaohsiung Medical University Hospital in August 2004. The clinical conditions of BPH were assessed by digital rectal examination, serum prostate-specific antigen determination, International Prostate Symptom Score (IPSS), and transrectal ultrasonography. The serum testosterone levels (total, free, and bioavailable) were also evaluated. The men also completed a health and demographics questionnaire and received a detailed physical examination.

The final study population consisted of 148 patients with a mean age of 59.8 years. Age correlated positively with prostate volume (r = 0.309, P <0.001), IPSS (r = 0.162, P = 0.029), and serum prostate-specific antigen level (r = 0.382, P <0.001). The serum testosterone levels (total, free, and bioavailable) did not correlate significantly with prostate volume or IPSS. On multivariate linear regression analysis, only age still correlated significantly with prostate volume (P <0.001).

In our study, the serum testosterone levels in aging men did not correlate with the measures of BPH, including prostate volume and IPSS, regardless of whether total, free, or bioavailable testosterone was used. Age correlated with the measures of BPH, especially prostate volume. Additional large studies are needed to confirm these preliminary results.