ESPE Abstracts (2016) 86 P-P1-744

A Prospective Evaluation of Urinary Gonadotrophins for Assessment and Management of Pubertal Disorders

Laura Lucaccionia,b, Jane McNeillyc, Martin McMillana, Andreas Kyriakoua, M. Guftar Shaikha, Sze Choong Wonga, Barbara Predierib, Lorenzo Iughettib, Avril Masona & S. Faisal Ahmeda

aDevelopmental Endocrinology Research Group, Royal Hospital for Children, University of Glasgow, Glasgow, UK; bDepartment of Medical and Surgical Sciences for Mother, Paediatric Unit, Children and Adults, University of Modena & Reggio Emilia, Modena, Italy; cDepartment of Biochemistry, Royal Hospital for Children, Glasgow, UK

Background: An increasing need for non-invasive, out-patient based investigations has necessitated a re-evaluation of urinary gonadotrophins (uGn) for assessing puberty.

Objective: Prospective evaluation of the relationship between first morning uGn measured by immunoassay and corrected for creatinine (uLH:uCr; uFSH:uCr), and basal serum gonadotropins (sLH, sFSH) and in response to LHRH stimulation test. Prospective evaluation of uGn trend in patients receiving GnRH analogue (GnRH-a) (Decapeptyl SR, 11.25 mg, every 10–12 weeks).

Methods: (15M) patients were evaluated for delayed puberty, 15 (1M) for suspected precocious puberty and 18 (3M) who were starting on GnRH-a. Three first-morning urine samples were collected before the stimulation test or before the GnRH-a injection. In the latter, three samples at midpoint between the injections were also collected. Data were expressed as median (range), and analyzed by SPSSv10.0 (P<0.05).

Results: The median coefficient of variation (CoV) for uLH:uCr and uFSH:uCr was 29% (0,140) and 24% (5,100), respectively. A strong correlation was detected between sLH and uLH:uCr (r=0.7; P<0.001) and between sFSH and uFSH:uCr (r=0.7; P<0.001). The median uLH:uCr for cases with a sLH peak of >5 IU/L and <5 IU/L was 0.12 (0.01, 0.57) and 0.02 (0.01, 0.11), respectively (P<0.001). Based on receiver operator characteristics analysis, a uLH:uCr value of 0.03 IU/mmol as a cut-off would detect a sLH peak>5 IU/L with a sensitivity of 89% and a specificity of 82%. In those on GnRHa therapy, the median uLH:uCr at 0.01 IU/mmol (0.0.14) was lower than those for cases with a peak stimulated sLH <5 IU/L (P=0.03). Median uLH:UCr and uFSH:UCr before injections was 0.01 IU/mmol (0.005, 0.043) and 0.34 IU/mmol (0.001, 0.6), respectively and at treatment midpoint was 0.01 IU/mmol (0.005, 0.042) and 0.09 IU/mmol (0, 0.42) (P<0.01).

Conclusion: UGn is a valuable, non-invasive instrument for diagnosis of early puberty. Its clinical utility in personalising GnRH-a therapy needs further exploration.