Idiopathic central precocious puberty in girls: presentation factors

Abstract

Background: It is sometimes difficult to distinguish between premature thelarche and precocious puberty in girls who develop breasts before the age of 8 years. We evaluated the frequencies of the signs associated with breast development and the factors influencing the presentation of girls with idiopathic central precocious puberty (CPP).

Methods: 353 girls monitored 0.9 +/- 0.7 year after the onset of CPP.

Results: The age at CPP was < 3 years in 2%, 3-7 years in 38% and 7-8 years in 60% of cases. Pubic hair was present in 67%, growth rate greater than 2 SDS in 46% and bone age advance greater than 2 years in 33% of cases. Breast development was clinically isolated in 70 (20%) cases. However, only 31 of these (8.8% of the population) had a prepubertal length uterus and gonadotropin responses to gonadotropin releasing hormone and plasma estradiol. The clinical picture of CPP became complete during the year following the initial evaluation.25% of cases were obese. The increase in weight during the previous year (3.7 +/- 1.4 kg) and body mass index were positively correlated with the statural growth and bone age advance (P < 0.0001). There was no relationship between the clinical-biological presentation and the age at puberty, the interval between the onset of puberty and evaluation, or the presence of familial CPP.

Conclusion: The variation in presentation of girls with CPP does not depend on their age, interval between the onset and evaluation, or familial factors. This suggests that there are degrees of hypothalamic-pituitary-ovarian activation that are not explained by these factors.

Figure 1

Percentages of pubic hair development, increased growth rate and bone age advance in 353 girls with idiopathic CPP.

Figure 2

Distribution of the LH and FSH peaks and LH/FSH peaks ration after GnRH test in 348 girls with idiopathic CPP.