Background: Luteinizing hormone stimulating hormone (LHRH) test is the gold standard test in the diagnosis of puberty precocıous (PP). The basal levels of FSH (follicular stimulating hormone) and LH (luteinizing hormone) cannot be always reliable.
Objective and hypotheses: To investigate the relation between the LHRH test and basal levels of FSH and LH.
Method: Girls with puberty started before the age 8 are investigated. Eighty nine girls diagnosed as central PP between January 2014-June 2015 were involved in the study. Laboratory examination (LH, FSH and estradiol), bone age and pelvic ultrasonography and LHRH test performed in all the patients with LH levels under 0.3 IU/l. Peak LH>5 IU/l accepted as positive for the test. The relation between basal hormone levels and LHRH test results are investigated.
Results: The ages of the patients ranged from 3.089.75 years. LHRH test performed in 59 patient. 39 patients (66.1%) with basal LH <0.1 IU/l test results and 22 of them (56.4%) had peak LH >5 IU/l. There was no correlation between basal LH and peak LH. We detected significant relation between basal FSH and peak LH (P<0.001, r: 56), and there was no correlation between basal and peak LH when the effects of bone age excluded.
Conclusıon: Basal LH levels below 0.1 IU/l is not reliable to exclude PP. In our study, 56.4% of the patients had unmeasurable basal LH levels but diagnosed as central PP with the LHRH test and clinical findings. In some studies, FSH secretion starts in prepubertal period and LH pulsations becomes dominant at the stage 2 puberty. Significant correlation of basal FSH and peak LH in this study, may suggest that basal levels of FSH can be predictive of PP diagnosis.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology