Serum inhibin B levels and the response to gonadotropin stimulation test in pubertal boys with varicocele

Purpose: The impact of varicoceles on gonadal function in adolescents has been evaluated using several parameters, including size of testes, hormonal levels and provocative endocrine testing. Inhibin B has been demonstrated to be decreased in men with testicular damage from conditions other than varicocele. We determine whether inhibin B levels are low in adolescent boys with varicocele, and if there is a relationship between inhibin B and an exaggerated response to gonadotropin-releasing hormone (Gn-RH) stimulation testing, testicular hypertrophy and/or varicocele bilaterality. Materials and Methods: We studied 9 boys at Tanner stages III to V of pubertal development who had either left or bilateral varicoceles. Basal inhibin B, follicle-stimulating hormone, luteinizing hormone and testosterone were measured. Each patient underwent Gn-RH stimulation testing. Results: All patients had essentially normal inhibin B levels for Tanner stage. Of the 9 boys 4 had an exaggerated response to Gn-RH stimulating testing. Inhibin B levels did not vary significantly either with the presence of bilateral or unilateral varicoceles or asymmetric testis. Conclusions: The lack of correlation between inhibin B levels and the aforementioned parameters failed to suggest that inhibin B has a significant role in the clinical assessment of testicular function in adolescents with varicocele. Further studies of larger populations may further elucidate the value of inhibin B levels and varicoceles.