A single sample GnRHa stimulation test in the diagnosis of precocious puberty

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A single sample GnRHa stimulation test in the diagnosis of precocious puberty Parvin Yazdani1*, Yuezhen Lin1, Vandana Raman2 and Morey Haymond3

Abstract Context: Gonadotropin-releasing hormone (GnRH) has been the standard test for diagnosing central precocious puberty. Because GnRH is no longer available, GnRH analogues (GnRHa) are now used. Random LH concentration, measured by the third-generation immunochemiluminometric assay, is a useful screening tool for central precocious puberty. However, GnRHa stimulation test should be considered, when a basal LH measurement is inconclusive. However optimal sampling times for luteinizing hormone (LH) have yet to be established. Purpose: To determine the appropriate sampling time for LH post leuprolide challenge. Methods: A retrospective analysis of multi-sample GnRHa stimulation tests performed in 155 children (aged 1–9 years) referred for precocious puberty to Texas Children’s Hospital. After 20 mcg/kg of SQ leuprolide acetate, samples were obtained at 0, 1, 3, and 6 hours. Results: Of 71 children with clinical evidence of central precocious puberty, fifty nine children had a peak LH >5 mIU/mL. 52 (88%) of these responders had positive responses at 1 hour (95% CI is 80–96%), whereas all 59 children (100%) had a peak LH response >5 mIU/mL at 3 hours (95% CI is 94-100%), P = 0.005. Conclusions: A single serum LH sample collected 3 hours post GnRHa challenge is the optimal sample to establish the diagnosis of central precocious puberty. Keywords: Central precocious puberty, Luteinizing hormone, Gonadotropin releasing hormone analogue

Background Central precocious puberty is the early onset of pubertal development as a result of gonadotropin release by the pituitary gland. Precocious puberty in a child can be associated with adverse consequences including compromised final adult height and psychosocial problems. Establishing the diagnosis of central precocious puberty requires documenting pubertal physical findings and measuring luteinizing hormone (LH) concentration, which is the key biochemical assessment of pubertal status. Gonadotropin-releasing hormone (GnRH)-stimulated plasma LH concentrations have been the mainstay for establishing the diagnosis of precocious puberty, but it is no longer available in the United States. GnRH analogue (leuprolide acetate) administered subcutaneously is a suitable substitute for GnRH in the diagnosis of central precocious puberty [1-5]. Ibanez et al. * Correspondence: [email protected] 1 Pediatric Endocrinology, Baylor College of Medicine, Houston 77024TX, USA Full list of author information is available at the end of the article

reported that a peak serum LH response >8 IU/L occurred in patients with progressive puberty and in patients with Tanner stage II puberty 3 hours post leuprolide acetate challenge [3]. The LH concentrations declined progressively from 3 to 6 hours poststimulation. In patients with non-progressive puberty and in pre-pubertal controls, the LH peak occurred between 3 and 6 hours after injec