Circulating ghrelin levels in girls with central precocious puberty are reduced during treatment with LHRH analog

Abstract

Decreased levels of ghrelin have been measured in growing children during puberty. No data are available for girls with central precocious puberty (CPP). To explore ghrelin changes before, during, and after GnRH analog treatment in girls with CPP. A sample of 20 Caucasian girls (8.08 +/- 0.65 years of age) with CPP was recruited. Height and weight, bone age, LH, FSH, 17beta estradiol (E(2)), and ghrelin were measured before starting treatment with GnRH analog, 18 months after therapy began and again 6 months after therapy discontinuation. LH and E(2) serum levels decreased significantly during treatment (2.45 +/- 2.03 vs 0.67 +/- 0.49 UI/l, P < 0.01 and 28.17 +/- 9.7 vs 15 pmol/l, P < 0.01 respectively), returning to baseline levels after the discontinuation of therapy (4.75 +/- 1.66 UI/l and 29.23 +/- 6.99 pmol/l respectively). LH peaked following LHRH stimulation significantly (P < 0.01) decreased during treatment (24.45 +/- 14.17 vs 1.3 +/- 0.18 UI/l) and then increased after therapy discontinuation (12.58 +/- 6.09, P < 0.01). Ghrelin decreased significantly (P < 0.05) during treatment (1849 +/- 322 vs 1207 +/- 637 pg/ml), and increased, though not significantly (P = 0.09) after therapy withdrawal (1567 +/- 629 pg/ml). Contrary to what is expected in physiologic puberty, where ghrelin is progressively reduced, the prepubertal hormone milieau induced by GnRHa treatment in patients suffering from central precocious puberty (CPP) did not promote an increase in ghrelin circulating levels. Therefore, in CPP, ghrelin secretion seems to be independent from pubertal development per se. Concomitant estrogen suppression during treatment may play a potential role in the regulation of ghrelin secretion in these girls.