Courteix D, Lespessailles E, Loiseau-Peres S, Obert P, Ferry B, Benhamou C L
Motor Performance Laboratory, School of Sports and Physical Education, Orléans University, France.
Rev Rhum Engl Ed. 1998 May;65(5):328-36.
Body weight is the most extensively studied correlate of bone mass and is widely used as a covariate in statistical evaluations of bone mineral parameters. Lean tissue mass (LTM) also correlates with bone mass. We evaluated the correlations linking each of these two parameters with bone mineral content and bone mineral density in 41 prepubertal girls, including ten swimmers, 18 gymnasts and 13 nonathletes. Lean tissue mass, bone mineral content and bone mineral density were measured using dual-energy X-ray absorptiometry (Hologic QDR-1000/W; Hologic Inc., Waltham, MA, USA). Forward stepwise multiple regression was used to evaluate correlations linking bone mineral content or density (the dependent variables) to body weight or lean tissue mass (the independent variables).
Body weight and lean tissue mass showed strong correlations with all bone mineral content and density measurements in the simple linear regression analysis, with lean tissue mass yielding the highest Pearson's correlation coefficients. In the multiple regression model, lean tissue mass consistently explained the largest proportion of the variance, whereas body weight had little influence or was eliminated from the model. The slopes of the regression lines of bone mineral content or density on body weight were significantly steeper in the subgroup of gymnasts (P < 0.001), whereas the slopes of the regression lines of bone mineral content or density on lean tissue mass were significantly less steep in the swimmers (P < 0.05).
Our data indicate that lean tissue mass is a significant predictor of bone mass in prepubertal girls and explains a larger part of the variance of bone mineral content and density than body weight. Use of body weight as a covariate in studies of bone mineral density may lead to erroneous results in prepubertal girls.
体重是与骨量相关性研究最为广泛的因素，在骨矿物质参数的统计评估中被广泛用作协变量。瘦组织质量（LTM）也与骨量相关。我们评估了41名青春期前女孩中这两个参数与骨矿物质含量和骨矿物质密度之间的相关性，其中包括10名游泳运动员、18名体操运动员和13名非运动员。使用双能X线吸收法（Hologic QDR - 1000/W；美国马萨诸塞州沃尔瑟姆市Hologic公司）测量瘦组织质量、骨矿物质含量和骨矿物质密度。采用向前逐步多元回归来评估骨矿物质含量或密度（因变量）与体重或瘦组织质量（自变量）之间的相关性。
在简单线性回归分析中，体重和瘦组织质量与所有骨矿物质含量和密度测量值均呈现出强相关性，其中瘦组织质量的皮尔逊相关系数最高。在多元回归模型中，瘦组织质量始终解释了最大比例的方差，而体重影响甚微或从模型中被剔除。体操运动员亚组中，骨矿物质含量或密度与体重的回归线斜率显著更陡（P < 0.001），而游泳运动员中，骨矿物质含量或密度与瘦组织质量的回归线斜率显著更平缓（P < 0.05）。
我们的数据表明，瘦组织质量是青春期前女孩骨量的重要预测指标，且比体重能解释更大比例的骨矿物质含量和密度方差。在青春期前女孩的骨矿物质密度研究中，将体重用作协变量可能会导致错误结果。
