Serum inhibin B levels in males with gonadal dysfunction.
OBJECTIVE
To determine whether inhibin B levels are reflective of the etiology of gonadal dysfunction.


METHODS
Institutional study.


METHODS
A tertiary care university-affiliated infertility clinic.


METHODS
Forty-four men: 16 with primary testicular failure, 10 with partial idiopathic hypogonadotropic hypogonadism (IHH), 8 with primary germ cell failure, one with iatrogenic hypogonadotropic hypogonadism, one with untreated Kallmann's syndrome, and 8 healthy fertile controls.


METHODS
Three individuals (one each with IHH, hypogonadotropic hypogonadism [HH], and Kallmann's syndrome) underwent treatment with human chorionic gonadotropin.


METHODS
Baseline serum inhibin B, FSH, LH, total testosterone and estradiol levels, and sperm concentrations were measured.


RESULTS
Serum inhibin B concentrations were significantly higher in fertile controls (255 +/- 59 pg/mL) than in men presenting with primary testicular failure (75 +/- 46 pg/mL, P<.0001) or in those presenting with primary germ cell failure (73 +/- 31 pg/mL, P<.0001). Inhibin B levels were also lower in males with partial IHH (187 +/- 112 pg/mL, P<.05). The patient with iatrogenic HH had a level of 184 pg/mL, whereas the patient with Kallmann's syndrome had nondetectable levels (<10 pg/mL). Serum inhibin B levels correlated positively with sperm concentration (P=.0001), and negatively with FSH levels (P=.01) and LH levels (P<.05). Human chorionic gonadotropin therapy altered inhibin B levels.


CONCLUSIONS
Inhibin B plays an important role as an endocrine regulator of FSH secretion, whereas gonadotropins are involved in the regulation of inhibin B secretion.
Department of Obstetrics and Gynecology, University of Southern California Keck School of Medicine, Los Angeles, USA.
B A
BA
Kolb
F Z
FZ
Stanczyk
R Z
RZ
Sokol
D016022:Case-Control Studies; D006063:Chorionic Gonadotropin / Q000627:therapeutic use; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007006:Hypogonadism / Q000097:blood* / Q000188:drug therapy*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D010455:Peptides / Q000097:blood* / Q000187:drug effects; D011237:Predictive Value of Tests; D029584:Prostatic Secretory Proteins; D013091:Spermatogenesis / Q000187:drug effects / Q000502:physiology; D013094:Spermatozoa / Q000502:physiology; D013739:Testosterone / Q000097:blood
D006063:Chorionic Gonadotropin; D010455:Peptides; D029584:Prostatic Secretory Proteins; C043076:beta-microseminoprotein; D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone