Researchers found that measuring LH hormone in urine after a triptorelin (GnRH) test can accurately tell if overweight or obese girls have central precocious puberty, offering a non‑invasive alternative to blood draws.

There are different opinions about the effect of body mass index on gonadotropin-releasing hormone stimulation tests in the laboratory diagnosis of precocious puberty in girls. The blood collection of precocious puberty girls with overweight or obesity is more difficult than those with normal body mass index. It is urgent to find non-invasive diagnostic methods for these girls. The purpose of the study was to evaluate the value of urinary gonadotropin after triptorelin stimulation tests for diagnosing central precocious puberty (CPP) in girls with overweight or obesity. This was a hospital data-based retrospective study. Overweight or obese girls with precocious puberty who presented to our pediatric endocrine clinic were involved. Triptorelin (Decapeptyl, 0.1 mg) stimulation tests were performed at 8:30 am. On the triptorelin test day, urine sample collected from 08:30 am to 8:30 pm was defined as the first stimulated urine. Serum and urinary luteinizing hormone (LH) were measured by immunochemiluminometric assay. Urinary creatinine (Cr) was also measured. There were 52 girls with overweight or obesity. They were divided into CPP (n = 36) and peripheral precocious puberty (PPP) (n = 16) groups. The stimulated urinary LH (ULH) concentration corrected by Cr (ULH/Cr), ULH concentration, and ULH content in the CPP group were significantly higher than those in the PPP group. When the first stimulated ULH/Cr, ULH concentration and ULH content were ≥ 239.142 IU/mol, 1.690 IU/L and 619.750 IU, and sensitivity for diagnosing CPP in girls with overweight or obesity were 90.9%, 78.8% and 81.8%, respectively, and specificity were all 100%, and the area under the curve were 0.939, 0.932 and 0.909, respectively. For overweight or obese girls with precocious puberty, the first stimulated ULH/Cr (cut-off value 240 IU/mol) may be used as a possible alternative to the invasive blood detection of triptorelin stimulation tests for diagnosing CPP. Not applicable.