[Gonadotropin response to GnRH and seminal parameters in low grade varicocele].
The pathogenetic role of varicocele in male infertility is still controversial. Although epidemiological data have clearly shown a higher incidence of varicocele in the population of subfertile and infertile patients, the real effectiveness of the surgical repair of varicocele, expressed as increase in the pregnancy rate, is still debated. The presurgical gonadotropin releasing hormone (GnRH) test is the most reliable predictive index of successful surgical outcome in terms of fertility. Only patients with an increased gonadotropin response (in particular FSH) to GnRH will benefit from the surgery. The aim of the present study was to evaluate the gonadotropin response to GnRH 50 micrograms i.v. in a group of patients with low-medium grade varicocele. At the beginning of the test, a fine needle was inserted into the forearm and kept patent by a saline solution. Blood samples were collected at the following experimental times: 0, +15, +30, +60, +90, +120 min. The stimulus was administered i.v. as bolus at time 0. The gonadotropin response to the stimulus and baseline levels of testosterone, PRL, 17 beta oestradiol and SHBG were compared with those of a control group. Moreover, all the patients underwent semen analysis after 3-7 days' abstinence and to ultrasound-doppler of the testis. Finally, we preliminarily looked for the presence of microdeletions on the Yq chromosome by polymerase chain reaction. No difference in baseline hormonal levels was found between the patients with varicocele and the controls; the LH response to GnRH was also similar in the two groups. The patients with varicocele showed a significantly (p = 0.03) higher FSH response (13.6 +/- 5.9 mUI/ml) to GnRH than controls (3.8 +/- 0.5 mUI/ml). A significant positive correlation (r = 0.6, p = 0.05) was found between LH peaks after GnRH testing and varicocele grade. Nine of 11 patients with varicocele showed significant seminal abnormalities (i.e., oligoasthenospermia): all patients showed a normal karyotype and no microdeletions were detected on the Yq chromosome. The authors underline the importance of presurgical GnRH testing in patients with low grade varicocele, given the close correlation between gonadotropin-stimulated peaks and varicocele grade found in the study. The presence of significant seminal abnormalities, even in patients with low grade varicocele, suggests the use of molecular genetic techniques to detect possible microdeletions on the Yq chromosome, which may be responsible for the infertility.
Foppiani
L
L
Dipartimento di Scienze Endocrinologiche e Metaboliche, Cattedra di Endocrinologia Università di Genova, Italia.
Piredda
S
S
Cavani
S
S
De Cassana
P
P
Valenti
S
S
Giusti
M
M
D000293:Adolescent; D000328:Adult; D005640:Follicle Stimulating Hormone / Q000097:blood; D007987:Gonadotropin-Releasing Hormone; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013076:Sperm Count; D014646:Varicocele / Q000503:physiopathology
D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone