ESPE Abstracts

Background: Leptin is mainly produced by adipocytes. In animal and human, it is a potnet anorectic and increases in obesity. Some reported that precocious puberty is prevelent in children with obesity.

Objective and hypotheses: This study was done to see the changes of blood leptin levels in both obese and non-obese children with early puberty or precocious puberty.

Method: Study patients consist of 325 children with early puberty or precocious puberty showing abnormally high blood leptin levels (>7.8 ng/ml) who visited our institute for GnRH stimulation tests between Jan 2014 and Feb 2015. Their medical records were reviewed retrospectively. And their clinical and laboratory data was analyzed.

Results: They are 273 girls and 52 boys. Their mean ages are 9.2±1.7 years. 254 out of 325 (78%) were non-obese, and 71 (22%) were obese. Hyperleptinemia was more frequent in non-obese group than obese group. Blood leptin levels (ng/mL) was significantly higher in obese group compared to non-obese group, 17.0±7.8 vs 12.6±4.9, respectively (P<0.001). In obese group, boy’s blood leptin levels (ng/mL) are significantly higher than girl’s, 23.2±11.2 vs 16.1±6.8, respectively (P<0.05). Blood leptin levels does not show any significant difference between GnRH (+) (peak LH >5 mIU/ml) and GnRH (−) groups. In GnRH (+) group, their age was significantly older compared to the age of GnRH (−) group in both girls and boys (P<0.05). Interestingly, obese GnRH (+) girl’s age was younger than non-obese GnRH (+) girls (P<0.05), this would be said that obesity may associates with earlier pubertal onset in GnRH (+) girls with hyperleptinemia.

Conclusion: hyperleptinemia was more frequently found in non-obese sexually precocious children than expected. Further study regarding the mechanism of hyperleptinemia and its clinical significance in non-obese children with early puberty or precocious puberty is necessary.