Clinical application value of Inhibin B alone or in combination with other hormone indicators in subfertile men with different spermatogenesis status: A study of 324 Chinese men

Background In this study, we investigated the clinical value of serum Inhibin B alone or in combination with other hormone indicators in subfertile men. Methods This is a multicenter study involving 324 men from different cities in China. Testicular volume, routine semen analysis, serum Inhibin B, anti‐Müllerian hormone (AMH), follicle‐stimulating hormone (FSH), luteinizing hormone (LH), testosterone, estradiol, and prolactin were measured. Testicular tissue samples were also analyzed in 78 of 129 patients with azoospermia to distinguish impaired spermatogenesis from obstructive azoospermia. Results The concentration of Inhibin B, FSH, and AMH is related to spermatogenesis. For men with impaired spermatogenesis, including mild‐to‐moderate oligozoospermia (IMO) and severe oligozoospermia (ISO), serum levels of Inhibin B and FSH are highly correlated with sperm counting. However, in patients with idiopathic moderate oligozoospermia or severe oligozoospermia, there was no significant correlation between Inhibin B (or FSH) and sperm concentration. The upper cutoff value of Inhibin B to diagnose ISO is 58.25 pg/ml with a predictive accuracy of 80.65%. To distinguish between nonobstructive azoospermia (NOA) and obstructive azoospermia (OA), the area under the curve (AUC) for AMH + Inhibin B + FSH is very similar to Inhibin B (0.943 vs. 0.941). The cutoff level of Inhibin B to diagnose nonobstructive azoospermia is 45.9 pg/ml with a positive and negative prediction accuracy of 97.70% and 85.71%, respectively. Conclusion In summary, Inhibin B is a promising biomarker alone or in combination with other hormone indicators for the diagnosis of testicular spermatogenesis status, helping clinical doctors to distinguish NOA from OA.