Pettersson U, Nordström P, Alfredson H, Henriksson-Larsén K, Lorentzon R
Department of Surgical and Perioperative Science, Sports Medicine Unit, Umeå University, S-901 87 Umeå, Sweden.
Calcif Tissue Int. 2000 Sep;67(3):207-14. doi: 10.1007/s002230001131.
The purpose of this cross-sectional study was to investigate the influence of two different types of weight-bearing activity, muscle strength, and body composition on bone mineral density (BMD), bone mineral content (BMC), and bone area in three different groups of late adolescent girls. The first group consisted of 10 females participating in competitive rope-skipping (age 17.8 +/- 0.8 years) training for 6.7 +/- 3.1 hours/week; the second group consisted of 15 soccer players (age 17.4 +/- 0.8 years) training for 6.1 +/- 2.0 hours/week; and the third group consisted of 25 controls (age 17.6 +/- 0.8 years) with physical activity of 0.9 +/- 1.1 hours/week. The groups were matched for age, height, and weight. BMD (g/cm(2)), BMC (g), and bone area (cm(2)) of the total body, lumbar spine, hip, total femur, distal femur, diaphyses of femur and tibia, proximal tibia, and humerus were measured using dual-energy X-ray absorptiometry (DXA). Bone density was also assessed in the radial forearm site of the dominant limb in the rope skippers and in 10 matched controls. The rope skippers had 22% higher BMD at the ultradistal site (P < 0.01). Both high-activity groups had significantly higher BMD (P < 0.05) at most loaded sites compared with the control group. When adjusting for differences in lean mass and starting age of sport-specific training between the activity groups, the rope-skipping group had a higher BMD of the total body, lumbar spine, and right humerus compared with the soccer group. They also had a significantly higher bone area of the total body, total femur, and the proximal femur than both other groups, and a significantly higher bone area of the tibia diaphysis, compared with the soccer group. In a multivariate analysis among all subjects (n = 50), all BMD sites, except the femur diaphysis, distal femur, and proximal tibia, were significantly related to type of physical activity (beta = 0.25-0.43, P < 0.05). The bone area values at different sites were strongly related to muscle strength and parameters related to body size [height, weight, lean mass, fat mass, and body mass index (BMI)]. In conclusion, it appears that in late adolescent women, weight-bearing activities are an important determinant for bone density, and high impact activities such as jumping also seem to be associated with a modification of the bone geometry (hence, the bone width) at the loaded sites.
这项横断面研究的目的是调查两种不同类型的负重活动、肌肉力量和身体成分对三组不同的青春期晚期女孩的骨矿物质密度（BMD）、骨矿物质含量（BMC）和骨面积的影响。第一组由10名参加竞技跳绳的女性组成（年龄17.8±0.8岁），每周训练6.7±3.1小时；第二组由15名足球运动员组成（年龄17.4±0.8岁），每周训练6.1±2.0小时；第三组由25名对照组女性组成（年龄17.6±0.8岁），每周体育活动时间为0.9±1.1小时。三组在年龄、身高和体重方面进行了匹配。使用双能X线吸收法（DXA）测量全身、腰椎、髋部、全股骨、股骨远端、股骨和胫骨骨干、胫骨近端和肱骨的BMD（g/cm²）、BMC（g）和骨面积（cm²）。还对跳绳者优势肢体的桡骨前臂部位以及10名匹配的对照组进行了骨密度评估。跳绳者在超远端部位的BMD高22%（P<0.01）。与对照组相比，两个高活动组在大多数负重部位的BMD均显著更高（P<0.05）。在调整活动组之间瘦体重和特定运动训练起始年龄的差异后，与足球组相比，跳绳组全身、腰椎和右肱骨的BMD更高。与其他两组相比，她们全身、全股骨和股骨近端的骨面积也显著更高，与足球组相比，胫骨骨干的骨面积也显著更高。在对所有受试者（n=50）进行的多变量分析中，除股骨干、股骨远端和胫骨近端外，所有BMD部位均与体育活动类型显著相关（β=0.25 - 0.43，P<0.05）。不同部位的骨面积值与肌肉力量以及与身体大小相关的参数[身高、体重、瘦体重、脂肪量和体重指数（BMI）]密切相关。总之，在青春期晚期女性中，负重活动似乎是骨密度的重要决定因素，而诸如跳跃等高冲击力活动似乎也与负重部位的骨几何形状（即骨宽度）的改变有关。
