青少年青春期骨量指标评价中的混杂因素及其校正

Confounding factors in the determination of bone mass during adolescent youngsters and the correction

目的:探讨儿童、青少年骨量评价中体格生长的混杂因素,并提出可行的校正方法。方法:调查于2001-10/2002-11在重庆市3所学校(小学、中学和大学各1所)完成,3所学校以班级为抽样单位,选择健康儿童、青少年161名作为调查对象,均在调查前填写知情同意书。使用单光子骨矿分析仪测定调查对象的非优势侧桡骨远端1/3处骨矿含量和骨宽,并测定其身高、体质量,采用相关分析及多元线性回归分析体格生长指标对骨矿含量的影响。结果:儿童、青少年161名全部进入结果分析,无脱落。①儿童、青少年骨矿含量值、体格发育与年龄的关系:骨矿含量值与年龄呈正相关性(r男生=0.90,r女生=0.79,P<0.01)。骨宽、身高、体质量与年龄呈正相关性(r男生=0.75,0.85,0.79;r女生=0.57,0.72,0.71,P<0.01)。②儿童、青少年骨宽、骨矿含量值与骨密度的关系:除≥12且<14岁组外,在多元线性回归模型中采用骨宽进行校正得到的骨密度值可较好消除骨骼体积的混杂作用。结论:青春期儿童骨量评价过程中需考虑年龄、骨宽、身高和体质量等影响因素;骨密度值虽可在一定程度消除骨宽的影响,但在儿童快速生长发育时期仍需慎用。在流行病学调查中采用多元线性回归模型可以消除骨宽、身高和体质量的混杂作用。

AIM： To discuss the potential confounding factor of physique growth in the bone mass determination in children and youths, and offer feasible correction method. METHODS： The investigation was conducted at the 3 schools （one from elementary school, middle school and university） of Chongqing city from October 2001 to November 2002. Classes of the 3 schools were considered as sampling unit. 161 healthy children and youths were selected as obser vational objects. They all signed the informed consents. Bone mineral content and bone width at the one-third part of distal radius at non-superiority side were assessed by single-photon absorptiometer, height and body mass were measured at the same time. The effects of index of physique growth on content of bone mine were detected with correlation analysis and multivariate linear regression. RESULTS： Totally 161 children and youths were involved in the result analysis, without drop-out. ①Correlation of bone mineral content and physique growth with age in children and youths： The mineral content had positive correlation with age （rmale=0.90,rfemale=0.79,P 〈 0.01 ）. Bone width. height and body mass had positive correlation with age （rmale=0.75,0.85, 0.79;rfemale=0.57,0.72,0.71 ,P 〈 0.01）. ②Relation of bone width and bone mineral content with bone mineral density （BMD） in children and youths： Except those ≥ 12 and 〈 14 years old group, the BMD obtained by correcting of bone width in multiple linear regression models could eliminate mixture of bone fully. CONCLUSION： Age, bone width, height and body mass, etc. should be regarded in the evaluation of bone content in adolescent children, BMD can eliminate the effects of bone width in some degree, but it should be used carefully in the rapid growth of children. Using multiple linear regression models can reduce the mixture effects of bone width, height and body mass in epidemiological study.