Selective reduction of elevated FSH levels in infertile men by pulsatile LHRH treatment.

In order to investigate whether isolated elevated FSH levels in men with idiopathic oligospermia can be lowered by pulsatile LHRH therapy, six patients were treated for 6 weeks with 5 micrograms LHRH pulses every 2 h. The pulses were delivered from a portable minipump (Zyklomat) through a subcutaneously inserted needle. At the end of treatment prepulse serum LH levels were no different from the levels before treatment while serum FSH was significantly reduced in all patients (16.9 +/- 2.5 U/l vs 11.3 +/- 1.9 U/l, mean +/- SEM; P less than 0.01). The normal FSH range was reached in one of the six patients. The areas under the LH curves following the first and the last (i.e. 504th) pulse were no different, while the areas under the FSH curves were significantly smaller (2870 +/- 434 vs 1776 +/- 237 U/l X min; P less than 0.01). Serum testosterone and oestradiol were significantly higher at the end of treatment (11.0 +/- 1.2 vs 15.2 +/- 1.9 nmol/l 146 +/- 18 vs 214 +/- 25 pmol, respectively). Thus increased FSH levels in men with idiopathic oligospermia can be selectively reduced by pulsatile LHRH treatment. If the increased FSH levels are not the result but rather a factor contributing to the pathogenesis of certain types of oligospermia these findings may have implications for the treatment of this condition.