Correlation Analysis of Serum Inhibin B, Endothelin, Human Epididymal Secretory Protein 4 and Sperm Quality in Patients with Varicocele.

OBJECTIVE: This study aims to explore the correlation of serum inhibin B, endothelin (ET) and human epididymal secretory protein 4 (HE4) with sperm quality in patients with varicocele (VC) to provide new insights for diagnosis, treatment and prognosis. METHODS: From May 2022 to February 2025, 64 patients with VC (all underwent varicocelectomy) and 64 healthy controls with matched age and body mass index (BMI) were recruited. Fasting blood and semen samples were collected early in the morning for enzyme-linked immunosorbent assay (ELISA) quantification of serum inhibin B and ET as well as seminal plasma HE4 levels. Standard semen analysis was performed to evaluate sperm concentration, motility and morphology. Correlations between biomarkers and sperm quality and VC severity were assessed using Pearson/Spearman tests. Pre- and post-operative changes were analysed using paired t-test. RESULTS: Patients with VC showed significantly reduced inhibin B (p < 0.05) and elevated ET and HE4 compared with the controls (p < 0.05). The combined detection using inhibin B + ET + HE4 showed sensitivity and specificity values of 89.06% and 65.63% for VC, respectively. Inhibin B exhibited a positive correlation with sperm density, total motility and progressive motility (p < 0.01), whereas ET and HE4 exhibited inverse relationships (p < 0.05). Postoperative follow-up at 3 months showed that inhibin B levels in patients with VC increased compared with the preoperative levels (p < 0.05), while the levels of ET and HE4 decreased (p < 0.05). CONCLUSIONS: Inhibin B, ET and HE4 are closely related to sperm quality, with reduced inhibin B and statistically elevated ET and HE4 levels observed in patients with VC.