Serum leptin levels in patients with progressive central precocious puberty

Leptin is a metabolic signal that may be involved in signaling adequacy of energy metabolism for the onset of reproductive function. The aim of this s tudy was to investigate the relationship between leptin serum levels and pu bertal development in girls with progressive central precocious puberty (CP P). We investigated longitudinally 14 girls with CPP before and during trea tment with depot leuprorelin acetate. Mean (+/- SEM) chronological age and bone age at start of therapy were 6.0 +/- 0.6 y and 9.5 +/- 0.7 y, respecti vely. Leptin was determined by RIA. Girls with CPP showed no significant di fference in leptin levels at pretreatment and after 1 and 2 y of treatment compared with healthy girls of the same body mass index (BMI). Mean leptin SD score adjusted for BMI was 0.31 +/- 0.4, 0.24 +/- 0.2, and 0.49 +/- 0.3, respectively (not significant). In a stepwise regression analysis model wi th BMI, bone age, chronological age, basal and stimulated LH, estradiol, de hydroepiandrosterone, androstenedione, and clinical pubertal signs, BMI was the only parameter that showed a significant correlation with leptin (p = 0.006). In conclusion, these data suggest that serum leptin levels are not significantly elevated at the onset of CPP compared with normal girls. Trea tment with depot gonadotropin releasing hormone agonist seems to have no in fluence on leptin concentrations. As in normal girls, serum leptin levels i n girls with CPP are mainly determined by BMI. Thus, we have no evidence th at alterations of leptin are related to premature onset of puberty.