Leptin is closely related to body fat in prepubertal children aged 8-11 years

Background: In adults and obese children, serum leptin concentrations are closely related to body fat. Aim: To investigate whether such a relationship between leptin concentrations and body fat is also evident in children with a relatively normal body composition. Methods: The study was a cross-sectional population study in 170 Caucasian children (91 boys and 79 girls), with a mean age of 9.99 +/- 0.6 y (range 8.5 - 10.9 y) and a mean BMI of 17.49 +/- 2.6 (range 12.8 - 28.1). Serum leptin was measured and compared to total body fat as determined by dual-energy X-ray absorptiometry. Results: In the whole population, serum leptin concentrations were highly correlated with total body fat (r = 0.83, p < 0.001). A stepwise forward multi-regression analysis revealed that the inclusion of other anthropometrical data did not add any significance to the model. Leptin concentrations were significantly higher in girls (5.2 ng/ ml) than in boys (3.2 mg/ ml; p = 0.003). Gender differences still prevailed (p = 0.007) after adjusting for number of kilograms of fat tissue. Conclusion: This study shows that, already at the young age of 9 - 11 y, an adult-like pattern of regulation of leptin exists. This indicates similar risk factor dependency of leptin across all age groups.