Department of Orthopedics, Xuanwu Hospital Capital Medical University, National Clinical Research Center for Geriatric Diseases, Beijing, People's Republic of China.
National Clinical Research Center for Geriatric Diseases, Beijing, People's Republic of China.
BMC Musculoskelet Disord. 2024 Aug 21;25(1):655. doi: 10.1186/s12891-024-07782-7.
Older subjects have a higher risk for vertebral compression fracture. Maintaining a higher bone mineral density (BMD) at this age can protect individuals from osteoporosis-related events. Body mass index (BMI) has been found to have a robust association with BMD. However, excessive BMI is detrimental to bone health and may cause systemic disorders. Therefore, the present study aimed to determine the association between BMI and BMD, and identify a reasonable BMI range.
A total of 961 participants were recruited from community-dwelling residents between August 2021 and May 2022. A weighted multivariate linear regression model was applied to identify the relationship between BMI and BMD. Meanwhile, subgroup stratified analysis by BMI quartile and gender was also performed. A non-linear relationship and threshold value were determined based on the smooth curve fittings and threshold effects analysis model.
A robust relationship was found between BMI and BMD, which remained significant in subgroups stratified by gender and BMI quartile. The BMI inflection point values in lumbar BMD and femoral neck BMD were 25.2 kg/m and 27.3 kg/m, respectively. For individuals with BMI < 25.2 kg/m, an increase in BMI was related to an increase in lumbar BMD. For BMI > 25.2 kg/m, an increase in BMI was associated with a decrease in lumbar BMD. For subjects with BMI < 27.3 kg/m, the femoral neck BMD rose by 0.008 kg/m for each unit rise in BMI. However, when BMI exceeded 27.3 kg/m, the femoral neck BMD increased only by 0.005 kg/m. Fracture risk assessment based on the spinal deformity index (SDI) failed to determine the optimal BMI range.
This study found an inflection point between BMI and lumbar/ femoral neck BMD in older community-dwelling subjects. An appropriate BMI but not an excessive BMI may allow older adults to have a better BMD.
老年人发生椎体压缩性骨折的风险更高。在这个年龄段保持较高的骨密度（BMD）可以保护个体免受与骨质疏松症相关的事件。体重指数（BMI）与 BMD 有很强的相关性。然而，过高的 BMI 不利于骨骼健康，并可能导致全身疾病。因此，本研究旨在确定 BMI 与 BMD 之间的关系，并确定合理的 BMI 范围。
2021 年 8 月至 2022 年 5 月，共招募了 961 名来自社区居住居民的参与者。应用加权多元线性回归模型来确定 BMI 与 BMD 之间的关系。同时，还按 BMI 四分位和性别进行了亚组分层分析。根据平滑曲线拟合和阈值效应分析模型，确定了非线性关系和阈值。
发现 BMI 与 BMD 之间存在很强的关系，这种关系在按性别和 BMI 四分位分层的亚组中仍然显著。腰椎 BMD 和股骨颈 BMD 的 BMI 拐点值分别为 25.2 kg/m 和 27.3 kg/m。对于 BMI<25.2 kg/m 的个体，BMI 的增加与腰椎 BMD 的增加有关。对于 BMI>25.2 kg/m 的个体，BMI 的增加与腰椎 BMD 的减少有关。对于 BMI<27.3 kg/m 的受试者，BMI 每增加 1 单位，股骨颈 BMD 增加 0.008 kg/m。然而，当 BMI 超过 27.3 kg/m 时，股骨颈 BMD 仅增加 0.005 kg/m。基于脊柱畸形指数（SDI）的骨折风险评估未能确定最佳 BMI 范围。
本研究在老年社区居住者中发现了 BMI 与腰椎/股骨颈 BMD 之间的拐点。适当的 BMI 而不是过高的 BMI 可能使老年人有更好的 BMD。
