Background: Hypogonadotropic hypogonadism (HH) in females is an uncommon and heterogeneous condition. There is little data regarding biochemical profile of gonadotropins to further substantiate the diagnosis.
Objective: To evaluate the gonadotropaic secretion profile after GnRH infusion in a female cohort diagnosed with HH.
Patients and methods: GnRH iv infusion test (0120 min) were performed in 17 patients (17.5±2.3 years) with suspicious of HH for pubertal delay or primary amenorrhea associated with: Group1 (G1)- acquired or congenital pituitary pathology (n=7) or G2- hypo/anosmia (n=6) or G3- lack of spontaneous pubertal progression after a brief estrogenic therapy or lack of pubertal clinical and biochemical progression for one year (n=4). LH, FSH at 0, 15, 30, 45, 60 and 120 min (IFMA) and basal Estradiol (ECLIA) were determined. Basal pubertal cutoffs were defined as FSH > 1.5 IU/L and basal LH >0.3 IU/L.
Results: Basal FSH <1.5 IU/L and LH <0.3 IU/L were found in 88% and 82% of patients, respectively. All patients had basal E2 < 15 pg/ml. FSH peak occurred in all the patients at 120 minutes (maximum 8 IU/L), whereas the occurrence of the LH surge was variable (maximum 8.9 IU/L). Areas under the curve of both gonadotropins were compared among three groups and they did not show any significant difference. Peaks LH were: G1: 3.4±2.5 IU/L, G2: 1.8±0.42 IU/L and G3: 5.2±3 IU/L. FSH peaks were: G1: 3.9±2.4 IU/L, G2: 3±1 IU/L, and G3: 4.9±2.9 IU/L.
Conclusion: The occurrence of simultaneous basal FSH <1.5 IU/L, basal LH <0.3 IU/L and E2 <15 pg/ml, or peak values LH < 8.9 or FSH < 9 IU/L after the infusion of GnRH support the diagnosis of HH in females suspected of this condition. Patients with hypo/anosmia showed the lower gonadotropin profile variability.
01 - 03 Oct 2015
European Society for Paediatric Endocrinology