ANDROGEN OR ESTROGEN EFFECTS ON HUMAN PROSTATE

Prostate development and disease are androgen dependent. However, the nature of hormonal effects on the prostate of healthy young men is not clear. We, therefore, measured prostate size in males chronically exp osed to high doses of androgens (AS; habitual anabolic steroid abusers ; n=15) or estrogens (E; male to female transsexuals; n=11) and compar ed the results with those in age-matched healthy eugonadal men without known prostate disorders. Prostate size was measured by planimetric u ltrasound as cross-sectional areas and maximal dimensions in three ort hogonal dimensions with a 7.5-megahertz B-mode sector scanner biplane in a transrectal transducer at 2.5 mm steps from the base to the apex of prostate. Total prostate volume (TPV) was reconstructed from planim etric sections, central prostate volume (CPV) was calculated by the el lipsoidal formula from the appropriate three maximum dimensions, and p eripheral prostate volume was determined by the difference between TPV and CPV. Compared with age-matched controls, TPV was normal (-2%) in AS (P=0.752) and reduced by 31% in E (P=0.002), whereas CPV was increa sed by 20% in AS (P=0.002) and reduced by 46% in E (P=0.002), and the ratio of CPV/peripheral prostate volume was increased by 77% in AS (P <0.001) and decreased by 33% in E (P=0.047). Blood sex hormone-binding globulin was elevated by nearly 500% in E (P <0.001), but was reduced by 47% in AS (P=0.003). Prostate-specific antigen was normal (-6%) in AS (P=0.799) and decreased by 86% in E (P=0.002). Prostatic acid phos phatase was increased by 26% in AS (P=0.007), but was unchanged (-28%) in E (P=0.106). Total and free testosterone levels were reduced to ca strate levels in E, whereas LH, FSH, and total testosterone levels wer e significantly reduced in AS. We conclude that in the human prostate of young men, CPV is more hormonally sensitive than TPV, and during hi gh dose treatment, CPV is preferentially increased by chronic androgen treatment and decreased by chronic estrogen treatment. The reduction of TPV by estrogens was less than expected if solely attributable to i nhibition of endogenous gonadotropin and testosterone secretion, sugge sting that estrogens also have a positive effect on the normal human p rostate. The reversibility and long term significance of androgen-indu ced stimulation of CPV and, in particular, its relationship to the ons et and severity of benign prostatic hyperplasia remain to be clarified .