Serum Leptin Concentrations in Extremely Obese Childen

ABSTRACT

PURPOSE: The purpose of this study is to investigate whether there is a difference in leptin concentrations between those of children of normal weight and extremely obese children. METHODS: We measured serum concentrations of leptin in 70 extremely obese subjects(7 to 12 years, 20 girls and 50 boys), whose serums had been frozen at -70degrees C. Height, weight, obesity index, and body mass index were measured. Radioimmunoassay for serum leptin was performed using Human Leptin RIA Kit. RESULTS: The mean age was 10.1 years old. The mean serum concentration of leptin in extremely obese children was 15.0+/-6.8ng/ml. The mean leptin level in girls was 15.2+/-6.7ng/ml compared with 15.0+/-6.7ng/ml in boys(P=0.91). The mean obesity index in girls was 58.7+/-8.1% compared with 62.1+/-11.2% in boys. The mean body mass index in girls was 25.6+/-1.9 compared with 26.8+/-2.1 in boys. Serum leptin concentrations correlated with the body mass index(r=0.38, P=0.001). The mean leptin level in the extremely obese group was significantly higher than that in the normal group of the same age(range, 10 to 12 years, P<0.001). CONCLUSION: Serum leptin concentrations highly correlated with body mass indices in extremely obese children. Because serum leptin levels in extremely obese children were remarkably high compared to those in normal group and there was no difference in leptin levels between girls and boys, it is speculated that obese children are resistant to endogenous leptin production.