Dowthwaite Jodi N, DiStefano James G, Ploutz-Snyder Robert J, Kanaley Jill A, Scerpella Tamara A
Department of Orthopedic Surgery, State University of New York Upstate Medical University, 550 Harrison St., Suite 128, Syracuse, NY 13202, USA.
Bone. 2006 Oct;39(4):895-900. doi: 10.1016/j.bone.2006.04.007. Epub 2006 Jun 6.
This study tests the hypotheses that (1) Tanner I and Tanner II girls comprise distinct maturational cohorts, exhibiting BMD differences that are not explained by age and body size alone; and (2) within these distinct maturational cohorts, BMD is higher in gymnasts than non-gymnasts, independent of age and body size. Premenarcheal artistic gymnasts (n=28) and non-gymnasts (n=28) were evaluated. Fan-beam DXA measured areal BMD (aBMD) at the forearm, femoral neck, and lumbar spine; fat free mass (FFM) was derived from whole-body scans. Height, weight, physical activity and calcium intake were assessed. Group means were compared using ANOVA; ANCOVA was used to adjust for age, height and FFM. For all 3 sites and both maturity levels, gymnasts had higher aBMD than non-gymnasts, independent of age and body size (7.2-20.8%, p<0.04). After adjustment for age, height and FFM, Tanner II gymnasts demonstrated lower aBMD than Tanner I gymnasts at the femoral neck (7.6%, p<0.05); no other maturity group comparisons yielded statistically significant differences independent of age and body size. In conclusion, for both Tanner groups, the osteogenic role of impact activity is evident at all three sites. Trends in Tanner group differences in aBMD were specific to gymnast and non-gymnast activity groups and therefore were not generalizable to all subjects. Overall, aBMD correlations and ANCOVA results differ by activity group, maturity level and site. These results highlight the need to consider both maturity and activity status in studies assessing bone accrual.
（1）坦纳I期和坦纳II期女孩构成不同的成熟队列，表现出的骨密度差异不能仅用年龄和体型来解释；（2）在这些不同的成熟队列中，体操运动员的骨密度高于非体操运动员，且与年龄和体型无关。对月经初潮前的艺术体操运动员（n = 28）和非体操运动员（n = 28）进行了评估。采用扇形束双能X线吸收法测量前臂、股骨颈和腰椎的面积骨密度（aBMD）；无脂肪量（FFM）由全身扫描得出。评估了身高、体重、身体活动和钙摄入量。使用方差分析比较组均值；协方差分析用于调整年龄、身高和FFM。对于所有3个部位以及两个成熟水平，体操运动员的aBMD均高于非体操运动员，且与年龄和体型无关（7.2 - 20.8%，p < 0.04）。在调整年龄、身高和FFM后，坦纳II期体操运动员在股骨颈处的aBMD低于坦纳I期体操运动员（7.6%，p < 0.05）；在与年龄和体型无关的情况下，其他成熟组比较均未产生统计学上的显著差异。总之，对于两个坦纳组，冲击活动的成骨作用在所有三个部位都很明显。坦纳组aBMD差异的趋势特定于体操运动员和非体操运动员活动组，因此不能推广到所有受试者。总体而言，aBMD相关性和协方差分析结果因活动组、成熟水平和部位而异。这些结果凸显了在评估骨量积累的研究中需要同时考虑成熟度和活动状态。
