Schousboe John T, Binkley Neil, Leslie William D
Park Nicollet Clinic and HealthPartners Institute, Minneapolis, MN, USA; Division of Health Policy and Management, University of Minnesota, Minneapolis, MN, USA.
University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
J Clin Densitom. 2025 Apr-Jun;28(2):101577. doi: 10.1016/j.jocd.2025.101577. Epub 2025 Feb 18.
Bone mineral density (BMD) measurement is less precise amongst those with body mass index (BMI) > 30 kg/m. We hypothesized that the association of BMD with incident hip and major osteoporotic fractures (MOF; hip, clinical vertebral, forearm, or humerus) becomes weaker with increasing BMI.
Our study population was 75,391 individuals age ≥ 50 years who had a bone density test in the province of Manitoba 1998 to 2018. BMD of the total hip was assessed on GE Lunar densitometers. Incident MOF and hip fractures were ascertained using linked health claims data over a mean (SD) follow-up of 8.6 (5.3) years. The associations of total hip BMD with incident major osteoporotic and hip fractures were estimated with Cox proportional hazards models including an interaction term between BMI category and BMD to test if the association of BMD with incident fractures varies by BMI.
The multivariable adjusted associations of total hip BMD with incident MOF did not vary by BMI (hazard ratio [HR] 1.56, 95 % C.I. 1.30, 1.85 for BMI ≥ 40 kg/m; HR 1.36, 95 % C.I. 1.17, 1.58 for BMI <18.5 kg/m; p-value for interaction 0.14). However, the association of total hip BMD with incident hip fracture was stronger for those with BMI ≥ 35 kg/m (HR 2.16, 95 % C.I. 1.71, 2.74) compared to those with BMI <18.5 kg/m (HR 1.48, 95 % C.I. 1.19, 1.84, p-value 0.001 for interaction).
The associations of total hip BMD with incident major osteoporotic and hip fracture are as strong for those with very high BMI as for those with normal BMI. However, total hip BMD may have a weaker association with incident hip fracture among underweight individuals. Further studies to confirm and explain this finding are warranted.
在体重指数（BMI）>30kg/m²的人群中，骨密度（BMD）测量的精确性较低。我们假设，随着BMI的增加，BMD与髋部骨折及主要骨质疏松性骨折（MOF；髋部、临床椎体、前臂或肱骨骨折）的关联会变弱。
我们的研究人群为1998年至2018年在曼尼托巴省进行骨密度检测的75391名年龄≥50岁的个体。使用GE Lunar骨密度仪评估全髋部的BMD。通过关联健康索赔数据确定MOF和髋部骨折的发生情况，平均（标准差）随访时间为8.6（5.3）年。采用Cox比例风险模型估计全髋部BMD与主要骨质疏松性骨折及髋部骨折发生的关联，模型中包含BMI类别与BMD的交互项，以检验BMD与骨折发生的关联是否因BMI而异。
全髋部BMD与MOF发生的多变量校正关联在不同BMI水平间无差异（BMI≥40kg/m²时，风险比[HR]为1.56，95%置信区间[CI]为1.30至1.85；BMI<18.5kg/m²时，HR为1.36，95%CI为1.17至1.58；交互作用p值为0.14）。然而，与BMI<18.5kg/m²的人群相比，BMI≥35kg/m²的人群中，全髋部BMD与髋部骨折发生的关联更强（HR为2.16，95%CI为1.71至2.74）（交互作用p值为0.001）。
对于BMI非常高的人群，全髋部BMD与主要骨质疏松性骨折及髋部骨折发生的关联与BMI正常的人群一样强。然而，体重过轻的个体中，全髋部BMD与髋部骨折发生的关联可能较弱。有必要进行进一步研究以证实并解释这一发现。
