MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.
Department of Nephrology, Transplantology and Internal Medicine, Medical University of Gdańsk, Gdańsk, Poland.
Osteoporos Int. 2021 Apr;32(4):689-698. doi: 10.1007/s00198-020-05603-w. Epub 2020 Sep 19.
Low body mass index (BMI) is an established risk factor for fractures in postmenopausal women but the interaction of obesity with bone microarchitecture is not fully understood. In this study, obesity was associated with more favourable bone microarchitecture parameters but not after parameters were normalised for body weight.
To examine bone microarchitecture in relation to fat mass and examine both areal bone mineral density (aBMD) and microarchitecture in relation to BMI categories in the UK arm of the Global Longitudinal Study of Osteoporosis in Women.
Four hundred and ninety-one women completed questionnaires detailing medical history; underwent anthropometric assessment; high-resolution peripheral quantitative computed tomography (HRpQCT) scans of the radius and tibia and DXA scans of whole body, proximal femur and lumbar spine. Fat mass index (FMI) residuals (independent of lean mass index) were derived. Linear regression was used to examine HRpQCT and DXA aBMD parameters according to BMI category (unadjusted) and HRpQCT parameters in relation to FMI residuals (with and without adjustment for anthropometric, demographic and lifestyle covariates).
Mean (SD) age was 70.9 (5.4) years; 35.0% were overweight, 14.5% class 1 obese and 7.7% class 2/3 obese. There were significant increasing trends according to BMI category in aBMD of whole body, hip, femoral neck and lumbar spine (p ≤ 0.001); cortical area (p < 0.001), thickness (p < 0.001) and volumetric density (p < 0.03), and trabecular number (p < 0.001), volumetric density (p < 0.04) and separation (p < 0.001 for decreasing trend) at the radius and tibia. When normalised for body weight, all HRpQCT and DXA aBMD parameters decreased as BMI increased (p < 0.001). FMI residuals were associated with bone size and trabecular architecture at the radius and tibia, and tibial cortical microarchitecture.
Significant trends in HRpQCT parameters suggested favourable bone microarchitecture at the radius and tibia with increasing BMI but these were not proportionate to increased weight.
研究脂肪量与骨微结构的关系，并探讨英国妇女骨质疏松全球纵向研究（GLOW）中骨密度（BMD）和骨微结构与 BMI 分类的关系。
491 名女性完成了详细的病史问卷；进行了人体测量评估；进行了桡骨和胫骨的高分辨率外周定量 CT（HRpQCT）扫描和全身、股骨近端和腰椎的 DXA 扫描。得出脂肪量指数（FMI）残差（与瘦体重指数无关）。使用线性回归分析按 BMI 分类（未调整）和 HRpQCT 参数与 FMI 残差（与人体测量、人口统计学和生活方式协变量调整或不调整）的关系来检查 HRpQCT 和 DXA 骨密度参数。
平均（标准差）年龄为 70.9（5.4）岁；35.0%超重，14.5%为 1 级肥胖，7.7%为 2/3 级肥胖。按 BMI 分类，全身、髋部、股骨颈和腰椎的 BMD 呈显著递增趋势（p≤0.001）；皮质面积（p<0.001）、厚度（p<0.001）和体积密度（p<0.03），桡骨和胫骨的骨小梁数量（p<0.001）、体积密度（p<0.04）和分离（p<0.001 呈递减趋势）。体重标准化后，所有 HRpQCT 和 DXA 骨密度参数均随 BMI 增加而降低（p<0.001）。FMI 残差与桡骨和胫骨的骨大小和小梁结构以及胫骨皮质微结构有关。
HRpQCT 参数呈显著递增趋势，提示桡骨和胫骨的骨微结构随着 BMI 的增加而改善，但与体重的增加不成比例。
