Department of Biostatistics, Boston University School of Public Health, 801 Massachusetts Ave, Third Floor, Boston, MA, 02118, USA.
Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.
Osteoporos Int. 2024 Jul;35(7):1205-1212. doi: 10.1007/s00198-024-07068-7. Epub 2024 Apr 8.
A knowledge gap exists in associating later life's osteoporotic fracture and middle adulthood's BMI trajectories. We observed an association showing those transitioning from overweight to normal weight face a higher fracture risk in late adulthood, emphasizing the potential benefits of maintaining a stable BMI to reduce late-life fractures.
Numerous studies on the relationship between obesity and fractures have relied on body mass index (BMI) at a single time point, yielding inconclusive results. This study investigated the association of BMI trajectories over middle adulthood with fracture risk in late adulthood.
This prospective cohort study analyzed 1772 qualified participants from the Framingham Original Cohort Study, with 292 (16.5%) incident fractures during an average of 17.1-year follow-up. We constructed BMI trajectories of age 35-64 years based on latent class mixed modeling and explored their association with the risk of fracture after 65 years using the Cox regression.
The result showed that compared to the BMI trajectory Group 4 (normal to slightly overweight; see "Methods" for detailed description), Group 1 (overweight declined to normal weight) had a higher all-fracture risk after age 65 (hazard ratio [HR], 2.22, 95% CI, 1.13-4.39). The secondary analysis focusing on lower extremity fractures (pelvis, hip, leg, and foot) showed a similar association pattern.
This study suggested that people whose BMI slightly increased from normal weight to low-level overweight during 30 years of middle adulthood confer a significantly lower risk of fracture in later life than those whose BMI declined from overweight to normal weight. This result implies the potentially beneficial effects of avoiding weight loss to normal weight during middle adulthood for overweight persons, with reduced fracture risk in late life.
在将晚年骨质疏松性骨折与中年时期 BMI 轨迹联系起来方面，存在知识差距。我们观察到一种关联，表明从中度超重转变为正常体重的人在晚年面临更高的骨折风险，这强调了保持稳定 BMI 以降低晚年骨折风险的潜在益处。
许多关于肥胖与骨折之间关系的研究依赖于单一时间点的体重指数 (BMI)，得出的结果不一致。本研究调查了中年时期 BMI 轨迹与晚年骨折风险之间的关联。
这项前瞻性队列研究分析了弗雷明汉原队列研究中的 1772 名合格参与者，在平均 17.1 年的随访期间发生了 292 例（16.5%）骨折事件。我们根据潜在类别混合建模构建了 35-64 岁的 BMI 轨迹，并使用 Cox 回归探索了它们与 65 岁后骨折风险的关系。
结果表明，与 BMI 轨迹组 4（正常至轻度超重；详细描述见“方法”）相比，组 1（超重降至正常体重）在 65 岁后发生所有骨折的风险更高（风险比 [HR]，2.22，95%CI，1.13-4.39）。针对下肢骨折（骨盆、臀部、腿部和脚部）的二次分析显示出类似的关联模式。
本研究表明，在中年 30 年期间 BMI 从正常体重略微增加到低水平超重的人，晚年骨折风险明显低于 BMI 从超重降至正常体重的人。这一结果表明，对于超重者来说，避免从中度超重减重至正常体重可能具有潜在的益处，可以降低晚年骨折风险。
