Presentation of 493 Consecutive Girls with Idiopathic Central Precocious Puberty: A Single-Center Study

BACKGROUND Despite the number of reported data concerning idiopathic central precocious puberty (CPP) in girls, major questions remain including its diagnosis, factors, and indications of gonadotropin releasing hormone (GnRH) analog treatment. METHODS A retrospective, single-center study was carried out on 493 girls with CPP. RESULTS Eleven girls (2.2%) were aged less than 3 years. Breast development was either isolated (Group 0, n = 99), or associated with one sign, pubic hair development, growth rate greater than 2 standard deviation score (SDS) or bone age (BA) >2 years above chronological age, (Group 1, n = 187), two signs (Group 2, n = 142) or three signs (Group 3, n = 65). The interval between onset of puberty and evaluation, body mass index (BMI) SDS, plasma luteinising hormone (LH) concentrations (basal and peak) and LH/ follicle-stimulating hormone (FSH) peak ratio after GnRH test, plasma estradiol and uterus length were significantly greater in Groups 2 and 3 than in Groups 0 and 1 respectively. 211 (42.8%) patients were obese and/or had excessive weight gain during the year before puberty. Obese girls more often had BA advance of >2 years (p = 0.0004) and pubic hair development (p = 0.003) than the others. BMI did not correlate with LH or with LH/FSH peak ratio. Girls with familial history of early puberty (41.4%) had greater frequencies of pubertal LH/FSH peak ratios (p = 0.02) than the others. During the 31 years of the study, there was no increase in the frequency of CPP or variation in its characteristics. CONCLUSION Obesity is associated with a higher BA advance and higher frequency of pubic or axillary hair development but not with LH secretion, suggesting that obesity accelerates adrenarche but not the maturation of the hypothalamic-pituitary-ovarian axis. The LH/FSH peak ratio was more frequently pubertal in girls with a familial history of early puberty, suggesting that this maturation depends on genetic factors.