Serum leptin level and its association with bone mineral density in obese children

Objective To investigate serum leptin level and its relationship with bone mineral density in obese children from Changsha City.Methods One hundred and nineteen obese children and 103 normal children aged 7 to 12 years from five primary schools of Changsha City were enrolled.Obesity was assessed based on the body mass index(BMI).Dual energy X-ray absorptiometry(DEXA) was used to determine bone mineral density(BMD) and body composition.Serum leptin level was measured using enzyme-linked immunosorbentassay(ELISA).Results The obesity group had higher height,weight,BMI,waist circumference and waist to hip ratio(WHR) compared with the normal group(P0.01).BMD,bone mineral content(BMC),lean mass(LM),fat mass(FM),percentage of body fat(%BF) and leptin concentration in the obesity group were significantly higher than those in the normal group(P0.01).Serum leptin level was positively correlated with BMD,BMC,LM and FM(r=0.528-0.903,P0.01).Multiple stepwise regression analysis indicated that BMI and %BF were independent influencing factors for serum leptin level.Conclusions Obese children have higher serum leptin level.Serum leptin concentration is significantly correlated with BMD and body composition.BMI and %BF are independent influencing factors for serum leptin level in children.