[Serum leptin in eutrophic and overweight Venezuelan children and adolescents].

Leptin is closely related to obesity and its complications. In order to determine serum levels of this hormone in children and adolescents, and its associations to age, gender, socioeconomic status, nutritional anthropometrical status and dietary intake, 166 children and adolescents (91 normal and 75 obese, aged 2 to 15 years), from low socioeconomic status were assessed. A socioeconomic evaluation (Grafffar-Mendez C method), dietary intake (24 hour recalls), anthropometrical assessment and leptin by ELISA were performed. Normal or eutrophic was defined as weight for height (W/H) or Body mass index (BMI) and fatty area between 10th and 90th percentile. Obesity when indicators were over 90th percentile. Leptin was significantly higher in obese than in normal, without differences by gender or age. Leptin percentile distribution showed 11.53 microg/L and 24.29 microg/L as 90th percentile for normal and obese children, respectively. There was a tendency to inverse correlation among leptin, fat dietary intake and waist-thigh ratio. Excessive fat intake was associated to lower serum leptin. Results suggest that obese children had leptin resistance, independently of age and gender. It is recommended to develop nutritional education programs regarding obesity and dietary intake in order to prevent and control infantile obesity.