Serum Leptin Levels in Obese Children

ABSTRACT

PURPOSE: Leptin is a protein encoded by the ob gene that is expressed in adipocytes. It regulates eating behavior by the action to the satiety centers in the hypothalamus. In ob/ob mouse, adipocytes can not produce leptin because of a mutation in the ob gene which results in obesity. Whereas, leptin concentrations were elevated in obese adults, and leptin levels in obese children has not been studied much until now. The purpose of this study is to evaluate leptin concentrations in obese children and to find out correlating factors with leptin. METHODS: Thirty-six obese childrens whose weight is above 97 percentile of korean weight standard and 39 children with average weight were included. Height, weight, waist to hip ratio, fat weight and lean body mass were measured. The serum levels of leptin, insulin, cholesterol and triglyceride were measured. RESULTS: Mean age was 10.8 +/- 2.5 years in obese group and 10.6 +/- 2.6 years in control group. Obesity percent was 51.6 +/- 18.8% in obese and 8.8 +/- 10.2% in control group. Body mass index (BMI) was 26.3 +/- 5.8kg/m2 in obese group and 17.3 +/- 1.9kg/m2 in control group. Leptin levels of obese group (13.7 +/- 5.4ng/ml) were significantly higher than that of the control group (3.6 +/- 3.3ng/ ml). Leptin levels showed no significant difference by gender and by pubertal development. Leptin levels significantly correlated with BMI, obesity percent, fat weight, and serum cholesterol level but showed no significant correlation with lean body mass, serum fasting insulin and triglyceride levels. CONCLUSION: Serum leptin levels of obesity group were significantly higher than that of the control group, and they were correlated with BMI, obesity percent and fat weight. Additional research is necessary to assess the mechanism of leptin resistance in obese children.