The relationship between different subcutaneous adipose tissue layers, fatmass and leptin in obese children and adolescents

We studied the relationships of subcutaneous adipose tissue layers (SAT-lay ers), body fat mass (FM) and waist-to-hip ratio (WHR) with leptin in obese children and adolescents. Twenty-nine obese children and adolescents (12 bo ys: age: 11.3 +/- 3.7 yr; body mass index [BMI]: 28.5 +/- 4) and 17 girls ( age: 12.2 +/- 2.2 yr; BMI: 29.8 +/- 4.7) (mean +/- SD) were studied. FM was estimated by bioelectrical impedance. SAT-layers were determined at 15 dif ferent body sites from 1-neck to 15-calf by the Lipometer optical device. L eptin and insulin were determined by RIA. Maturity was associated with a gr eater thickness of certain SAT-layers from the upper body and with it lower thickness of SAT-layers from the abdominal region and lower extremities. S ignificant correlations were found for all estimates of adiposity and lepti n (all p<0.001). Waist and hip circumferences were not correlated to leptin after adjustment for FM. SAT-layers from the upper body were significantly and positively correlated to leptin. Multiple regression analysis revealed FM as a main contributor to the variation in leptin (R-2=0.53, p<0.0001). FM together with SAT-layers 5-front chest and 13-rear thigh explained 72% o f the variation in leptin (p<0.0001). In a body fat distribution model, hip circumference together with SAT-layers 4-upper back and 2-triceps explaine d 75% of the variation in leptin (p<0.0001). The results suggest that SAT-l ayers and their topography are main determinants for leptin in obese childr en and adolescents. Maturity in obese children is associated with higher va lues of upper body SAT-layers and lower values of abdominal and lower extre mities SAT-layers. Whether leptin is under the control of certain subcutane ous adipose tissue depots from the upper body remains to be elucidated by l ongitudinal studies.