Department of Mechanical Engineering, University of California-Berkeley, Berkeley, CA 94720-1740, USA.
J Bone Miner Res. 2010 May;25(5):994-1001. doi: 10.1359/jbmr.091033.
Although age-related variations in areal bone mineral density (aBMD) and the prevalence of osteoporosis have been well characterized, there is a paucity of data on femoral strength in the population. Addressing this issue, we used finite-element analysis of quantitative computed tomographic scans to assess femoral strength in an age-stratified cohort of 362 women and 317 men, aged 21 to 89 years, randomly sampled from the population of Rochester, MN, and compared femoral strength with femoral neck aBMD. Percent reductions over adulthood were much greater for femoral strength (55% in women, 39% in men) than for femoral neck aBMD (26% in women, 21% in men), an effect that was accentuated in women. Notable declines in strength started in the mid-40s for women and one decade later for men. At advanced age, most of the strength deficit for women compared with men was a result of this decade-earlier onset of strength loss for women, this factor being more important than sex-related differences in peak bone strength and annual rates of bone loss. For both sexes, the prevalence of "low femoral strength" (<3000 N) was much higher than the prevalence of osteoporosis (femoral neck aBMD T-score of -2.5 or less). We conclude that age-related declines in femoral strength are much greater than suggested by age-related declines in femoral neck aBMD. Further, far more of the elderly may be at high risk of hip fracture because of low femoral strength than previously assumed based on the traditional classification of osteoporosis.
尽管与年龄相关的骨密度（aBMD）和骨质疏松症的患病率已经得到了很好的描述，但人群中股骨强度的数据却很少。为了解决这个问题，我们使用定量计算机断层扫描的有限元分析来评估明尼苏达州罗切斯特市年龄分层队列中 362 名女性和 317 名男性的股骨强度，这些人年龄在 21 岁至 89 岁之间，是从人群中随机抽取的，并将股骨强度与股骨颈 aBMD 进行了比较。在成年后，股骨强度的降幅（女性为 55%，男性为 39%）远大于股骨颈 aBMD（女性为 26%，男性为 21%），这一效应在女性中更为明显。在女性中，强度的显著下降始于 40 多岁中期，而在男性中则推迟了十年。在老年时，与男性相比，女性的大部分力量不足是由于女性的力量损失更早开始，这一因素比峰值骨强度和骨丢失的年率的性别差异更为重要。对于两性来说，“股骨强度低”（<3000N）的患病率远高于骨质疏松症（股骨颈 aBMD T 评分低于-2.5）的患病率。我们的结论是，与年龄相关的股骨强度下降比与年龄相关的股骨颈 aBMD 下降所表明的要大得多。此外，由于股骨强度低，比以前基于传统骨质疏松症分类所假设的，更多的老年人可能面临髋部骨折的高风险。
