Leuprolide acetate gonadotrophin response patterns during female puberty

Abstract

Objective To assess normative data and the usefulness of spontaneous and LHRH analogue-stimulated serum LH and FSH levels measured by immunoradiometric assays (IRMA) in the evaluation of normal puberty. Design Prospective. Healthy girls in Tanner I and Tanner II from the local community were invited to participate (n = 47). Methods A leuprolide acetate test (500 mcg/m2; sc) was performed. LH and FSH levels were determined using IRMA. Tanner II girls were assessed every 6 months until Tanner V. Girls who progressed from Tanner II to Tanner III in the next 6 months were called Tanner II-2; otherwise, they were called Tanner II-1. Results The prepubertal upper limit (CI 95%) was 0Æ49 IU/l for basal LH and 5Æ1 IU/l for stimulated LH. Taking into account these LH cut-off limits, 72Æ2% and 66Æ7% of Tanner II-1 and 41Æ6% and 41Æ7% of Tanner II-2 subjects presented overlapping values for basal and stimulated LH, respectively, as compared with the Tanner I group. The cut-offs for basal and stimulated LH to predict progression from Tanner II to Tanner III in the next 6 months were a basal LH level ‡0Æ49 IU/l (Sensitivity = 0Æ58; 1-Specificity = 0Æ33) and a poststimulated LH level ‡4Æ75 IU/l (Sensitivity = 0Æ67; 1-Specificity = 0Æ44). Conclusion According to an IRMA, the basal and leuprolide acetate gonadotrophin response patterns during the beginning stages of puberty overlapped between Tanner I and Tanner II, and the cut-offs of basal and stimulated LH levels to predict progress from Tanner II to Tanner III had low sensitivities for the following 6 months.