肥胖儿童瘦素水平的变化及其与骨密度的关系

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

目的探讨长沙市肥胖儿童血清瘦素水平的变化及与骨密度（BMD）、身体成分的关系，为预防和治疗儿童肥胖及骨质疏松提供科学依据。方法从长沙市5所小学随机抽取119例肥胖儿童和103例正常儿童，采用双能X线骨密度仪（DEXA）进行全身扫描，测定骨密度及身体成分；采用酶联免疫吸附试验（ELISA）测定血清瘦素水平。结果①肥胖儿童的身高、体重、体重指数（BMI）、腰围和腰臀比均显著高于正常儿童（P〈0．01）。②肥胖儿童的全身骨密度、骨矿物质含量、瘦组织含量、脂肪组织含量、体脂百分比（％BF）及血清瘦素水平均显著高于正常儿童（P〈0．01）。③血清瘦素水平与儿童全身骨密度、骨矿物质含量、瘦组织含量、脂肪组织含量均呈显著正相关（r=0．528～0．903），其中瘦素水平与脂肪组织含量呈高度正相关（男：r=0．883，女：r=0．903）。多元逐步回归分析显示，BMI及％BF是儿童血清瘦素水平的独立影响因素。结论肥胖儿童血清瘦素水平升高，血清瘦素水平与骨密度及身体成分显著相关，BMI、％BF是儿童血清瘦素水平的独立影响因素。

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 （ P 〈 0.01 ）. 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 （P 〈 O. 01 ） . Serum leptin level was positively correlated with BMD, BMC, LM and FM （ r = 0. 528 - 0. 903, P 〈 0. 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.