Clinical and Investigative Orthopedics Surgery Unit, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, 10 Center Drive, Bldg. 10-CRC, Room 4-2339, MSC1498, Bethesda, MD, 20892, USA.
Harvard-MIT Division of Health Sciences and Technology, Harvard Medical School, Boston, USA.
Arch Osteoporos. 2023 Sep 16;18(1):119. doi: 10.1007/s11657-023-01327-6.
Hip fractures have steadily declined in the USA. We found that bone health, as measured by bone mineral density, has significantly improved over the past 30 years. Our findings contradict previous studies and offer one explanation for the decline in hip fractures.
Despite the widespread undertreatment of osteoporosis, hip fractures have been declining in the USA. The reasons for this decline are unclear; however, one possible explanation could be that the bone health has improved over time.
To determine the trends in bone density in the USA, we analyzed the bone mineral density scans of 7216 subjects across three generations in the Framingham Heart Study. We compared the mean femoral bone mineral density (BMD) between cohorts then constructed a linear regression model controlling for age, sex, BMI, and smoking rates.
We observed that the mean BMD of each successive Framingham cohort increased (p < 0.001). After controlling for age, subjects born later had higher BMD. The results from the linear-regression model developed on the original cohort indicated that the BMD of the women from the offspring and third generation were higher than what would be predicted. Younger generations demonstrated higher activity scores (p < 0.001), and lower smoking rates (p = 0.045).
These data suggest that bone health, measured by bone mineral density scans, is improving in later generations, in part due to decreased smoking rates and higher rates of activity.
美国的髋部骨折数量一直在稳步下降。我们发现，过去 30 年来，骨健康（通过骨密度测量）有了显著改善。我们的发现与之前的研究结果相矛盾，为髋部骨折数量下降提供了一种解释。
尽管骨质疏松症的治疗普遍不足，但美国的髋部骨折数量一直在下降。其下降的原因尚不清楚；然而，一个可能的解释是，随着时间的推移，骨骼健康状况有所改善。
为了确定美国骨密度的趋势，我们分析了弗雷明汉心脏研究中三代共 7216 名受试者的骨矿物质密度扫描结果。我们比较了各代人群的平均股骨骨密度（BMD），然后构建了一个线性回归模型，控制年龄、性别、BMI 和吸烟率。
我们观察到，每个连续的弗雷明汉队列的平均 BMD 都有所增加（p<0.001）。在控制年龄因素后，出生较晚的受试者具有更高的 BMD。原始队列的线性回归模型结果表明，后代和第三代女性的 BMD 高于预期。年轻一代的活动评分更高（p<0.001），吸烟率更低（p=0.045）。
这些数据表明，通过骨密度扫描测量的骨骼健康状况在后代中得到了改善，这在一定程度上是由于吸烟率降低和活动量增加所致。
