Adams Annette L, Sidell Margo, Gilfillan Alec D, Ryan Denison S, Schilcher Jörg, Black Dennis M
Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, CA 91101, United States.
Department of Biomedical and Clinical Sciences and Department of Orthopaedics, Linköping University, Linköping, Sweden.
JBMR Plus. 2025 Apr 23;9(7):ziaf071. doi: 10.1093/jbmrpl/ziaf071. eCollection 2025 Jul.
Atypical femur fractures (AFF) resemble stress fractures. Stress fractures can result from repetitive stresses like weight-bearing exercise and femoral geometry may influence where stress fractures manifest along the bone. Atypical femur fractures risk is demonstrably greater among Asian women compared to Caucasian women, with differences in femoral geometry hypothesized to contribute to elevated risk. Using a previously established cohort of older adult women, all with bisphosphonate (BP) use sometime during the study period (2010-2017) and some with AFF, we linked self-reported information on weekly exercise to enable evaluation of whether the average weekly minutes of exercise differed by race/ethnicity and whether accounting for any differences explains the increased AFF risk seen among Asian women. Data came from the longitudinal electronic health record of Kaiser Permanente Southern California. Atypical femur fractures were identified by expert review and adjudication of femur fracture radiographs. Race/ethnicity was categorized as White, Asian, and Other. Average weekly minutes of exercise were expressed in units of 15-min blocks. Bivariable and multivariable Poisson regression models were used to estimate incidence rate ratios (IRR) and 95% CI for the associations between exercise, race/ethnicity, and AFF. Exercise levels for all three race/ethnicity categories were different from each other at < .001. After adjusting for age, cumulative duration of BP use, and recency of BP use, the IRR for AFF risk in Asian women (compared to White women) was 4.96 (CI, 3.72-6.61). Adding exercise level to this same model did not change the estimate for Asian women meaningfully (IRR 5.03, CI, 3.77-6.71). Thus, the observed race/ethnicity variation in exercise levels does not appear to contribute to the elevated risk of AFF in Asian women.
非典型股骨骨折（AFF）类似于应力性骨折。应力性骨折可能由诸如负重运动等重复性应力导致，并且股骨几何结构可能会影响应力性骨折在骨上的表现位置。与白人女性相比，亚洲女性发生非典型股骨骨折的风险明显更高，据推测股骨几何结构的差异是导致风险升高的原因。我们利用一个先前建立的老年女性队列，她们在研究期间（2010 - 2017年）都曾使用过双膦酸盐（BP），部分女性发生了AFF，我们将自我报告的每周运动信息关联起来，以评估每周平均运动分钟数是否因种族/族裔而异，以及考虑这些差异是否能解释在亚洲女性中观察到的AFF风险增加情况。数据来自南加州凯撒医疗集团的纵向电子健康记录。非典型股骨骨折通过专家对股骨骨折X光片的审查和判定来确定。种族/族裔分为白人、亚洲人和其他。每周平均运动分钟数以15分钟为单位表示。使用双变量和多变量泊松回归模型来估计运动、种族/族裔与AFF之间关联的发病率比（IRR）和95%置信区间（CI）。所有三个种族/族裔类别的运动水平在<0.001水平上彼此不同。在调整年龄、BP使用的累积持续时间和BP使用的近期情况后，亚洲女性（与白人女性相比）发生AFF风险的IRR为4.96（CI，3.72 - 6.61）。在同一模型中加入运动水平对亚洲女性的估计值没有显著改变（IRR 5.03，CI，3.77 - 6.71）。因此，观察到的运动水平在种族/族裔上的差异似乎并未导致亚洲女性AFF风险升高。
