低体重和肥胖儿童身体成分特点及脂肪肌肉含量与骨密度相关性研究

张海燕，周群英

(眉山市妇幼保健院，四川 眉山 620010)

低体重和肥胖儿童身体成分特点及脂肪肌肉含量与骨密度相关性研究

张海燕，周群英

(眉山市妇幼保健院，四川 眉山 620010)

目的 探讨低体重和肥胖儿童身体成分特点及其脂肪肌肉含量与骨密度的相关性。方法 选择2015年6月至2016年6月于眉山市妇幼保健院儿保门诊体检的5～7岁儿童为研究对象，按体质量指数(BMI)分为低体重组、肥胖组和对照组，测量身体成分各项指标，包括体脂比、全身脂肪含量、肌肉含量及局部和全身骨密度，并对结果进行分析。结果 同性别儿童低体重组的体脂比、全身脂肪含量、肌肉含量及局部和全身骨密度均分别明显低于对照组，二者之间差异均具有统计学意义(t=3.076～3.326，均P<0.05)；同性别儿童对照组的体脂比、全身脂肪含量、肌肉含量及局部和全身骨密度均分别明显低于肥胖组，二者之间差异均具有统计学意义(t=2.998～3.427，均P<0.05)。经Logistic回归分析：低体重组儿童的肌肉含量与不同部位骨密度均呈正相关性(r=0.779～0.889，均P<0.05)；肥胖组男性儿童的肌肉含量与下肢骨密度、体脂比和全身脂肪含量与躯干骨密度均呈正相关性(r=0.779～0.882，均P<0.05)，肥胖组女性儿童肌肉含量与上肢骨密度，以及体脂比、全身脂肪含量和肌肉含量与下肢骨密度均呈正相关性(r=0.781～0.901，均P<0.05)；对照组儿童的肌肉含量与不同部位骨密度均呈正相关性(r=0.779～0.912，均P<0.05)，对照组女性儿童的体脂比、全身脂肪含量和肌肉含量均与下肢骨密度和全身骨密度均呈正相关性(r=0.805～0.912，均P<0.05)。结论 与正常儿童相比，低体重和肥胖儿童身体成分构成，各指标与骨密度的相关关系明显不同于正常儿童。在对儿保门诊儿童管理中，体重、体脂比、全身脂肪含量、肌肉含量的变化均是需要关注的重要指标，从而促进其骨骼健康发育。

体重；体脂比；全身脂肪含量；肌肉含量；骨密度

通过对处于生长发育期的儿童身体成分的分析可以了解儿童的营养健康和身体发育状况。处于不同状态生长发育期的儿童，其身体成分构成不尽相同[1]，如身体成分构成明显异常，将严重影响儿童骨骼及身体的健康发育[2-4]。本文分析了2015年6月至2016年6月于眉山市妇幼保健院儿保门诊体检的5～7岁儿童的身体成分特点及其脂肪肌肉含量与骨密度的相关性，为儿保门诊就诊儿童的常规化管理中的关注重点提供理论依据及数据参考。

1对象与方法

1.1研究对象

选取2015年6月至2016年6月于眉山市妇幼保健院儿保门诊体检的5～7岁儿童为研究对象，排除合并有内科外科基础疾病的儿童、早产儿、低体重出生儿，以及母亲孕期有妊娠期高血压疾病、妊娠期糖尿病等任何可能影响胎儿及婴幼儿生长发育疾病的儿童。

1.2研究方法

由专业人员测量每位研究对象的身高、体重，计算体质量指数(BMI)=体重(kg)/身高2(m2)。利用生物电阻抗分析仪测量身体成分各项指标：体脂比、全身脂肪含量、肌肉含量。利用DXA骨密度测量仪检测各个研究对象的上肢、下肢、躯干和全身骨密度。根据BMI将所纳入的研究对象分为三组，分别为低体重组、肥胖组和正常对照组。

1.3统计学方法

采用SPSS 22.0软件进行统计学分析，计量资料用均值±标准差表示，采用单因素方差分析进行组间比较，Logistic回归分析体脂比、全身脂肪含量、肌肉含量与局部和全身骨密度的相关性，以P<0.05为差异有统计学意义。

2结果

2.1研究对象基本特点

本次共纳入符合标准的研究对象749例，其中低体重组198例(男：102例，女:96例)、肥胖组237例(男：126例，女：111例)和对照组314例(男：162例，女：152例)。各组研究对象的年龄等基线相同。

2.2纳入研究的儿童身体成分特点

肥胖组男性儿童和女性儿童的BMI均分别高于低体重组的男性儿童和女性儿童；同性别儿童低体重组的体脂比、全身脂肪含量、肌肉含量及局部和全身骨密度均分别明显低于对照组，二者之间差异均具有统计学意义(均P<0.05)；同性别儿童对照组的体脂比、全身脂肪含量、肌肉含量及局部和全身骨密度均分别明显低于肥胖组，二者之间差异均具有统计学意义(均P<0.05)，见表1。

表1 纳入研究的儿童身体成分测量比较结果

注：t1、P1为低体重组与对照组比较；t2、P2为肥胖组与对照组比较。

2.3Logistic回归分析情况

经Logistic回归分析显示，低体重组男女儿童的肌肉含量与被研究各部位骨密度均呈正相关性(均P<0.05)；肥胖组男性儿童的肌肉含量与下肢骨密度、体脂比和全身脂肪含量与躯干骨密度均呈正相关性(均P<0.05)，肥胖组女性儿童肌肉含量与上肢骨密度，以及体脂比、全身脂肪含量和肌肉含量与下肢骨密度均呈正相关性(均P<0.05)；对照组儿童的肌肉含量与不同部位骨密度均呈正相关性(均P<0.05)，对照组女性儿童的体脂比、全身脂肪含量和肌肉含量与下肢骨密度和全身骨密度均呈正相关性(均P<0.05)，见表2。

表 2 Logistic回归分析纳入研究各组儿童的体脂比、脂肪含量和肌肉含量与骨密度之间的关系

(转下表)

(续上表)

分组性别 上肢骨密度(g/cm3) 下肢骨密度(g/cm3) 躯干骨密度(g/cm3) 全身骨密度(g/cm3) 体脂比全身脂肪含量肌肉含量体脂比全身脂肪含量肌肉含量体脂比全身脂肪含量肌肉含量体脂比全身脂肪含量肌肉含量对照组男r0.2980.3020.8090.3360.3910.7790.2070.3080.8060.3110.3050.887P>0.05>0.05<0.05>0.05>0.05<0.05>0.05>0.05<0.05>0.05>0.05<0.05女r0.401.0.3350.8830.8050.9120.8860.4010.3920.8050.8120.8360.883P>0.05>0.05<0.05<0.05<0.05<0.05>0.05>0.05<0.05<0.05<0.05<0.05

3讨论

3.1儿童身体成分科学管理及预防肥胖的重要性

本研究结果显示，低体重组同性别儿童的体脂比、全身脂肪含量均低于对照组，二者之间差异均具有统计学意义(均P<0.05)。对照组同性别儿童的体脂比、全身脂肪含量均低于肥胖组，二者之间差异均具有统计学意义(均P<0.05)。脂肪细胞只在1～5岁内增加，而体积要到青春前期才增大，小儿肥胖容易发展为成人肥胖，如发展为成人肥胖，其治疗效果很不理想，并且有增加高血压、糖尿病、心血管疾病等发病率的危险[5-8]。因此，对于青少年单纯性肥胖的预防，不仅要提前到青春前期，还要提前到儿童期。

3.2各身体成分指标与骨密度之间的关系及其科学管理的重要性

本研究中，经Logistic回归分析显示，低体重组儿童的肌肉含量与不同部位骨密度均呈正相关性(均P<0.05)。本研究中低体重男性、女性儿童，对照组男性、女性儿童表现一致，即仅肌肉含量对局部和全身骨密度影响显著；与诸多研究结果一致[9-13]。儿童时期是骨骼矿物化的最关键时期之一，这一时期的骨密度会直接影响其成年后理想的骨密度峰值，肌肉力量的改变会引起骨强度发生相应的变化，肌肉可影响骨代谢，通过收缩产生应力促进成骨，增加骨密度和骨量[14-17]。因此，对于这一年龄段低体重儿童可以通过加强锻炼，增加肌肉含量，以便达到促进骨骼健康发展的目的。

总之，与正常儿童相比，低体重和肥胖儿童身体成分构成，各指标与骨密度的相关关系明显不同于正常儿童。在儿保门诊儿童管理中，体重、体脂比、全身脂肪含量、肌肉含量的变化均是需要关注的重要指标，从而促进儿童骨骼的健康发育。

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[专业责任编辑： 史晓薇]

Characteristics of body composition and relativity of fat and lean masses with bone mineral density in low weight and obese children

ZHANG Hai-yan, ZHOU Qun-ying

(Meishan Maternal and Child Health Care Hospital, Sichuan Meishan 620010, China)

Objective To analyze the characteristics of body composition and relativity of fat and lean masses with bone mineral density (BMD) in low weight and obese children. Methods Children aged 5-7 years old receiving physical examination in Child Health Care Department of Meishan Maternal and Child Health Care Hospital from June 2015 to June 2016 were selected as study subjects and divided into low weight group, obese group and control group according to body mass index (BMI). Body composition indexes including percentage of body fat (PBF), fat mass (FM), lean mass (LM) and local and systemic BMD were measured and analyzed. Results Percentage of body fat, fat mass, lean mass and local and systemic bone mineral density in low weight group were significantly lower than those of children of same sex in control group, and differences had statistical significance (tvalue ranged 3.076 to 3.326, allP<0.05). Percentage of body fat, fat mass, lean mass and local and systemic bone mineral density in control group were significantly lower than those of children of same sex in obese group, and differences had statistical significance (tvalue ranged 2.998 to 3.427, allP<0.05). Logistic regression analysis showed that lean mass of children in low weight group was positively associated with bone mineral density at different parts (rvalue ranged 0.779 to 0.889, allP<0.05), lean mass was positively associated with lower limb bone mineral density and percentage of body fat and fat mass positively associated with trunk bone mineral density in obese group male children (rvalue ranged 0.779 to 0.882, allP<0.05), lean mass was positively associated with upper limb bone mineral density and percentage of body fat, fat mass and lean mass positively associated with lower limb bone mineral density in obese group female children (rvalue ranged 0.781 to 0.901, allP<0.05), and lean mass of children in control group was positively associated with bone mineral density at different parts (rvalue ranged 0.779 to 0.912, allP<0.05) and percentage of body fat, fat mass and lean mass were all positively associated with lower limb and systemic bone mineral density in control group female children (rvalue ranged 0.805 to 0.912, allP<0.05). Conclusion Body composition and correlation of each index with bone mineral density in low weight and obese children are different from those in normal children. In child health care department outpatient management, changes in body weight, percentage of body fat, fat mass, lean mass are important indicators demanding attention to enhance healthy bone development.

body weight; percentage of body fat (PBF); fat mass (FM); lean mass (LM); bone mineral density (BMD)

2016-08-15

张海燕(1981-)，女，主治医师，主要从事儿童保健工作。

周群英，副主任医师。

10.3969/j.issn.1673-5293.2017.07.003

R788

A

1673-5293(2017)07-0758-03