ESPE Abstracts

Background: Excess adiposity may influence various aspects of pubertal development, including the timing of pubertal initiation and hormonal parameters during puberty.

Objective and hypotheses: The aim of this study was to clarify the impact of BMI on LH secretion in response to GnRH stimulation test in girls diagnosed with central precocious puberty.

Method: Girls with central precocious puberty, who underwent GnRH-stimulation test during the time period of 2008–2012 were recruited. Using a stratified random sampling method, we obtained 359 subjects. Subjects were classified as normal weight (5th percentile≤BMI<85th percentile), overweight (85th percentile≤BMI<95th percentile), and obese (BMI ≥95th percentile) according to their BMI. We compared their pubertal development using the Tanner Scale, correlated sexual hormone parameters and LH secretion in response to GnRH stimulation test among the three groups.

Results: Among the 359 girls with precocious puberty whose data were in the final analysis, 122 girls were of normal weight (34%), while 119 children (33%) were overweight, and 118 (33%) were obese. The mean age at diagnosis of each group was 7.20±1.35, 7.23±0.87, and 7.26±0.68 years. The bone age for each group was 9.15±1.44, 9.79±0.97, and 9.89±0.97 years respectively. Peak LH levels after GnRH stimulation test were much higher in the normal weight group 18.95 (16.30–23.70) mIU/ml compared with the overweight and obese subjects which were 7.50 (3.90–11.80) and 7.20 (3.8–11.50) mIU/ml respectively (P<0.001 for all comparisons). By multivariate analysis, it was found that there was a significant negative association of BMI with peak stimulated LH level to the GnRH-stimulation tests (r=−0.546, P<0.001).

Conclusion: The higher BMI is associated with lower LH response to the GnRH-stimulation test in girls experiencing precocious puberty. Recommendations for future studies in this regard include that BMI should be considered when interpreting GnRH-stimulation tests.