Effects of gonadotropin and testosterone treatments on prostate volume and serum prostate specific antigen levels in male hypogonadism.

It is known that prostate specific antigen (PSA) is strongly androgen dependent, but little is known about the effects of gonadotropin and testosterone treatments on the prostate and serum PSA levels in male hypogonadism. We have therefore determined serum PSA levels before and 3 months after treatment in 13 patients with idiopathic hypogonadotropic hypogonadism (IHH) and 14 patients with Klinefelter's syndrome. Plasma FSH, LH, testosterone, PRL, testis and prostate volumes were also determined before and 3 months after treatments. Patients with IHH were treated with hCG/hMG and patients with Klinefelter's syndrome received testosterone treatment. PSA levels were determined by a kinetic enzyme immunoassay method. In patients with Klinefelter's syndrome FSH and LH levels were significantly decreased but total and free testosterone and PSA levels were significantly increased after 3 months of treatment. Right and left testicular volumes were not significantly changed whereas prostate volumes were significantly increased after treatment. In this group PSA levels were significantly and positively correlated with the prostate volume both before (r=0.54, P=0.048) and after treatment (r=0.61, P=0.012). In the IHH group total and free testosterone and PSA levels were significantly increased after gonadotropin treatment but FSH and LH levels did not change significantly. Right and left testicular volumes and the prostate volumes were also significantly increased after 3 months of gonadotropin treatment. In this group PSA levels were correlated with prostate volume before (r=0.74, P=0.004) treatment but not after therapy (r=0.35, P=NS). Our results show that serum PSA levels increase after gonadotropin and testosterone treatment in male hypogonadism, but this could not be used as an index for the evaluation of the androgen action in the treatment of male hypogonadism, since PSA levels following treatments were correlated with the prostate volume or T levels only in patients with Klinefelter's syndrome but not in the IHH group.