Age- and sex-dependent reference intervals of inhibin B in Chinese children on chemiluminescence analyzer

Abstract Backgroud: Inhibin B (INHB) is an emerging biomarker of sexual function diseases, but its clinical use in children is hindered due to the lacking reference intervals (RIs) based on age sex. Methods: A total of 622 healthy Chinese children were included and serum INHB and six conventional sex hormones were measured. INHB was partitioned by four age groups (<1y, 1~5y, 5~10y, 10~18y) and the corresponding RIs were determined with quantile. The effect of age on INHB was assessed using five models including linear, quadratic, cubic, S, and logarithmic. Spearman correlation was used to examine the associations between INHB and sex hormones. Results: Compared to the boys, girls had lower median concentrations and variability in INHB across four age groups. The optimal models for the effect of age on INHB were cubic (R2=0.440 for boys). The INHB concentration in the first and oldest age groups was more high than other groups (P≤0.001). Spearman’s correlation analysis showed sex-dependent association between INHB and conventional sex hormones (e.g. a positive association with PRL in boys). Conclusions: INHB level is influenced by age and gender, and our results provide specific RIs to facilitate to screen sexual function diseases in Chinese children.