Elevated basal luteinizing hormone (LH) and the ratio of LH to follicle-stimulating hormone (FSH) may be a marker for idiopathic central precocious puberty (ICPP) among girls, according to findings published in Frontiers in Endocrinology. They are potentially significant because, while the gonadotropin-releasing hormone (GnRH)-stimulation test is considered the “gold standard” for diagnosing CPP for children with early symptoms of puberty, it requires multiple blood samples to be taken to identify peak levels of LH and FSH. These findings suggest there may be an easier option for these young patients.

Researchers from The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University in China retrospectively reviewed patient data collected between 2016 and 2020 at their center. All 1578 patients diagnosed with  precocious puberty during the 5-year study period were reviewed; 1492 of them were included in the study.

Girls were diagnosed with ICPP (n=518) or non-CPP (n=974) and were aged mean 7.97±0.60 and 7.46±0.83 years (P <.001), were 133.12±5.88 and 129.16±6.94 cm tall (P <.001), and weighed 30.22±4.87 and 27.95±5.46 kg (P <.001), respectively. No significant trends in obesity were observed between cohorts (c2, 0.138; P =.710).


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The ICPP cohort had elevated LH (mean, 0.88 vs 0.12 mIU/L; P <.001), FSH (mean, 4.03 vs 3.12 mIU/L; P <.001), and LH/FSH (mean, 0.18 vs 0.23 mIU/L; P <.001) at baseline. Up to 120 minutes after stimulus with gonadotropin, the ICPP cohort had sustained elevated LH (all P <.001) and LH/FSH (all P <.001) but not FSH after 30 minutes (all P >.05).

After gonadotropin stimulation, LH and peak LH were significantly correlated (all P <.001), as were LH/FSH and peak LH/FSH (all P <.001).

The best cut-off points for discrimination between ICPP and non-CPP were peak LH/FSH of 0.601 mIU/L (area under the curve [AUC], 0.997; sensitivity, 0.988; specificity, 0.995), followed by LH/FSH at 60 minutes of 0.603 mIU/L (AUC, 0.988; sensitivity, 0.973; specificity, 0.930), LH/FSH at 90 minutes of 0.596 mIU/L (AUC, 0.985; sensitivity, 0.936; specificity, 0.974), and LH/FSH at 120 minutes of 0.540 mIU/L (AUC, 0.985; sensitivity, 0.948; specificity, 0.969).

The study authors cautioned that an abnormal LH level is not a sufficient diagnostic criterion for ICPP, and patients must still be monitored for manifestations of secondary sexual development. However, the authors said that basal LH and LH/FSH measurement can identify girls with CPP.  A single 60-minute poststimulus gonadotropin result of LH and LH/FSH can be used instead of a GnRH agonist stimulation test, or samples can be taken only at 0, 30, and 60 minutes after a GnRH agonist stimulation test. This reduces the number of blood draws required compared with the traditional stimulation test while still achieving a high level of diagnostic accuracy.

Ethics Statement: Written informed consent to participate in this study was provided by the participants’ legal guardian/next of kin.

Reference

Cao R, Liu J, Fu P, Zhou Y, Li Z, Liu P. The diagnostic utility of the basal luteinizing hormone level and single 60-minute post GnRH agonist stimulation test for idiopathic central precocious puberty in girls. Front Endocrinol. 2021;12:713880. doi:10.3389/fendo.2021.713880