title: Age-dependent inhibin B concentration in relation to FSH and semen sample qualities: a study in 2448 men.
abstract: Inhibin B is an important serum marker of spermatogenesis, whereas sensitivity and predicting power for the spermatogenic situation at several ages are under debate. We performed a retrospective analysis of data from 2448 men who attended our University-based male infertility clinic to evaluate inhibin B in relation to age and semen sample qualities in comparison with FSH. Moreover, the range of inhibin B in 82 nonobstructive azoospermic patients was correlated with the sperm retrieval in testicular sperm extraction procedures. Inhibin B correlated with FSH (Spearman rank correlation (R)=-0.50; P<0.00001). Inhibin B and inhibin B/FSH ratio (IFR) showed an inverse U-shaped dependence on age, whereas FSH showed a U-shaped dependence on age (optimum 20-40 years). However, in men with normal spermiograms inhibin B concentrations did not differ between age groups. Their levels of inhibin B amounted to 130.5, 54.5-247 ng/l (median, 10th-90th precentile), and of IFR to 38.3, 12.5-104.8 (median, 10th-90th percentile), which might be taken as the reference range. Using the 10th percentile of IFR, correct classification in normal or pathological semen groups was achieved in 99.1%. The percentage of aniline blue-negative spermatozoa, i.e. mature spermatozoa with protamines, did not correlate with FSH (P>0.05) but with inhibin B (R=0.15, P<0.001). The probability of retrieving testicular spermatozoa decreased with declining inhibin B: <20 ng/l sperm could never be found. Our results from a large group of men with a wide spectrum of semen qualities allow estimating reference values for inhibin B and IFR. Inhibin B and especially the IFR are more sensitive markers of male infertility than FSH alone.
authors: Klinik und Poliklinik für Dermatologie, Venerologie und Allergologie, Training Centre of the European Academy of Andrology, 04103 Leipzig, Germany. sonja.grunewald@medizin.uni-leipzig.de
authors: S
authors: S
authors: Grunewald
authors: H-J
authors: HJ
authors: Glander
authors: U
authors: U
authors: Paasch
authors: J
authors: J
authors: Kratzsch
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000097:blood* / Q000473:pathology; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D043373:Follicle Stimulating Hormone, Human / Q000097:blood*; D006801:Humans; D007248:Infertility, Male / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D007265:Inhibins / Q000097:blood*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D055101:Semen Analysis / Q000379:methods; D013076:Sperm Count; D013081:Sperm Motility; D053625:Sperm Retrieval; D055815:Young Adult
chemical_list: D015415:Biomarkers; D043373:Follicle Stimulating Hormone, Human; C422364:inhibin B; D007265:Inhibins