FSH stimulated inhibin B (FSH-iB): A novel marker for the accurate prediction of pubertal outcome in delayed puberty

Clinicians have long been struggling to find an effective tool as marker of entry into puberty. In search of a better diagnostic test as marker of entry into puberty present study was undertaken to look for stimulability of inhibin B and its potential role as marker of entry into puberty.

All children who needed to be evaluated for onset or prediction of puberty were included in study after informed consent. Patients with hypogonadotropic hypogonadism and children with normal puberty were taken as controls after informed consent. All patients were subjected to FSH stimulation test and Triptorelin stimulation test as per study protocol.

Present study revealed that inhibin B is stimulable in both male and female healthy normal children who were in puberty while it is non-stimulable in patients of hypogonadotropic hypogonadism. There was sexual dimorphism in basal as well as stimulated levels of inhibin B. On ROC analysis cut off of 116.14 pg/ml in male and 116.50 pg/ml in female had 100% sensitivity and 100% specificity for denoting entry into puberty. Validation of cut-off derived from control cohort was done in male subjects 14-18 years and female subjects 13-18 years presenting with delayed puberty. FSH stimulated inhibin B had maximum diagnostic power with 100% sensitivity, specificity, PPV and NPV for distinguishing CDGP and HH in both male and female.