Clinicians have long been struggling to find an effective tool to predict onset of puberty.To explore stimulability of inhibin B after exogenous FSH and it's potential role for prediction of onset of puberty.Study subjects were enrolled into "exploratory cohort"(n=42) and "validation cohort"(n=19). "Exploratory cohort" was further divided into Group-1(Healthy children with spontaneous puberty: SP, n=26) and Group-2 (Patients of hypogonadotropic hypogonadism: HH, n=16). "Validation cohort" included children who presented with complaints of delayed puberty.Participants were subjected to FSH stimulation test and GnRHa stimulation test. Cut-offs derived from "exploratory cohort" for basal and FSH stimulated inhibin B(FSH-iB) were applied on "validation cohort" .Basal LH, GnRHa stimulated LH, basal inhibin B and FSH-iB were compared with clinical outcome on prospective follow-up for prediction of onset of puberty.There was statistically significant increment in inhibin B after exogenous FSH in Group 1(SP) in both male(188.8 pg/ml;p-value-0.002) and female (1065 pg/ml;p-value-0.023) subjects. The increment was not statistically significant in Group 2(HH) in both genders. FSH-iB at a cut-off of 116.14 pg/ml in male and 116.50 pg/ml in female had 100% sensitivity and specificity for labelling entry into puberty. On application of these cut-offs on "validation cohort", FSH-iB had 100% PPV, NPV and diagnostic accuracy for prediction of onset of puberty.Inhibin B was stimulable in both male and female subjects. FSH-iB can be considered as novel and promising investigation for prediction of onset of puberty. Future studies are required for further validation.
Shakun Chaudhary, Rama Walia, Anil Bhansali, Devi Dayal, Naresh Sachdeva, Tulika Singh, Sanjay Kumar Bhadada