van Marken Lichtenbelt W D, Fogelholm M, Ottenheijm R, Westerterp K R
Department of Human Biology, University of Limburg, Maastricht, The Netherlands.
Br J Nutr. 1995 Oct;74(4):439-51. doi: 10.1079/bjn19950150.
The main purpose of the present study was to examine factors that affect bone mineral density (BMD) in female ballet dancers. Training history, Ca intake, body composition, total body BMD (TBMD) and site-specific BMD, and bone mineral content were described in twenty-four female ballet dancers (mean age 22.6 (SD 4.5) years). Training history was determined by questionnaires, Ca intake by 7 d dietary record, BMD and bone mineral content by dual-energy X-ray absorptiometry (DXA), total body water by 2H dilution, extracellular water by bromide dilution, body fat by underwater weighing (UWW; two-component model), DXA, and the four-component (4C) model. Dancers had a significantly lower body mass index (BMI 18.9 (SD 1.0) kg/m2) than controls (21.3 (SD 1.9) kg/m2), with significantly lower percentage body fat (17.4 (SD 3.9) v. 24.4 (SD 5.1)) but comparable fat-free mass. Mean TBMD (1.147 (SD 0.069) g/cm2) was significantly higher (6%) compared with that of a reference population. These high values could be attributed to the high BMD of legs and pelvis, the weight-bearing sites of the dancer's body. No relationship was found between age, start of ballet classes, period (years) of dancing, Ca intake, and BMD (total and site-specific). However, TBMD was positively related to BMI, and negatively related to the age of menarche. BMD of the legs was significantly related to BMI, and negatively related to the age of menarche. BMD of the legs was significantly related to daily period (h) of training. Depending on the method used the percentage body fat ranged from 16.4 (by DXA) to 18.3 by the 4C model. These differences were significantly related to the TBMD. Percentage body fat by the different methods was not significantly different, except for DXA and 4C model. The present study showed that, despite the factors that have a negative effect on BMD, such as low body mass and late menarche, BMD in female ballet dancers was relatively high. These high values were probably caused by high levels of weight-bearing physical activity.
本研究的主要目的是探讨影响女性芭蕾舞演员骨密度（BMD）的因素。描述了24名女性芭蕾舞演员（平均年龄22.6（标准差4.5）岁）的训练史、钙摄入量、身体成分、全身骨密度（TBMD）和特定部位骨密度以及骨矿物质含量。训练史通过问卷调查确定，钙摄入量通过7天饮食记录确定，骨密度和骨矿物质含量通过双能X线吸收法（DXA）测定，全身水含量通过2H稀释法测定，细胞外液通过溴化物稀释法测定，体脂通过水下称重法（UWW；双组分模型）、DXA和四组分（4C）模型测定。与对照组（21.3（标准差1.9）kg/m²）相比，舞者的体重指数（BMI 18.9（标准差1.0）kg/m²）显著更低，体脂百分比显著更低（17.4（标准差3.9）对24.4（标准差5.1）），但去脂体重相当。平均TBMD（1.147（标准差0.069）g/cm²）与参考人群相比显著更高（6%）。这些高值可能归因于腿部和骨盆的高骨密度，这是舞者身体的承重部位。未发现年龄、开始芭蕾舞课程的时间、舞蹈年限、钙摄入量与骨密度（全身和特定部位）之间存在关联。然而，TBMD与BMI呈正相关，与初潮年龄呈负相关。腿部骨密度与BMI显著相关，与初潮年龄呈负相关。腿部骨密度与每日训练时长（小时）显著相关。根据所使用的方法，体脂百分比范围从16.4（通过DXA）到4C模型的18.3。这些差异与TBMD显著相关。除DXA和4C模型外，不同方法测得的体脂百分比差异不显著。本研究表明，尽管存在对骨密度有负面影响的因素，如低体重和初潮延迟，但女性芭蕾舞演员的骨密度相对较高。这些高值可能是由高水平的负重体育活动导致的。
