目的比较2～6岁超重、单纯性肥胖儿童及低体质指数儿童的下肢骨矿物密度(BMD),探究肥胖和超重对骨骼强度的影响。方法选取2017年3月-2018年1月在北京市西城区妇幼保健院儿童保健中心进行幼儿园入园体检及超声骨密度检查儿童为研究对象,按体质指数(BMI)将被研究对象分为4组,其中对照组健康儿童118人,超重组儿童101人,肥胖组儿童100人,低BMI组117人,共计436人。利用方差分析对4组儿童BMD的检测值(Z值)进行比较,用单因素χ²检验和Logistic回归分析进一步分析4组儿童的BMI、性别、身高和体重对BMD的影响。结果超重组与对照组、低BMI组与对照组、低BMI组与超重组的Z值均差异无统计学意义(P>0.05);而肥胖组Z值分别明显低于与对照组、超重组及低BMI组的Z值,差异均有统计学意义(P <0.05);BMI、性别、身高、体重4个因素中,BMI及身高水平与BMD相关性有统计学意义(P<0.05),且为BMD下降的危险因素(OR> 1,P <0.05)。结论与正常健康儿童相比,超重儿童和低BMI儿童骨密度并无明显差异,而肥胖儿童骨密度明显下降。较高的BMI和较高的身高可能是BMD的危险因素。

Objective To compare the bone mineral density(BMD) of lower limbs in children age 2-6 years old with overweight,simple obesity and low body mass index(BMI),and to explore the effects of obesity and overweight on bone strength.Methods From March 2017 to January 2018,a total of 436 children who underwent physical examination and ultrasonic bone mineral density examination in kindergarten in our hospital were selected as the subjects of the study.The subjects were divided into four groups according to BMI,including 118 healthy children in the control group,101 children in the overweight group,100 children in the obesity group and 117 in the low BMI group.The detection value(Z value) of BMD in four groups of children was compared by ANOVA.The effects of BMI,sex,height and weight on BMD in four groups of children were further analyzed by single factor χ² test and Logistic regression analysis.Results There was no statistically significant difference in the Z values between the overweight group and the control group,the low BMI group and the control group,the low BMI group and the overweight group,respectively(P>0.05),while the Z value of the obesity group was significantly lower than that of the control group,the overweight group and the low BMI group,the difference was statistically significant(P <0.05);Among the four factors of BMI,sex,height and weight,there was significant correlation between BMI,height and BMD t(P <0.05),and they were the risk factors for BMD decline(OR> 1,P <0.05).Conclusion Compared with normal healthy children,there was no significant difference in bone mineral density between the overweight children and the low BMI children,but the bone mineral density decreased obviously in the obese children.Higher BMI and higher height may be the risk factors for BMD.