Department of Exercise Sciences, University of Toronto, 55 Harbord St., Toronto, Ontario, M5S 2W6, Canada.
Metabolism. 2013 Oct;62(10):1401-5. doi: 10.1016/j.metabol.2013.05.004. Epub 2013 Jun 13.
Recent data suggest that women with type 2 diabetes mellitus (T2DM) might be more susceptible to fractures due to an impaired adaptive response to mechanical load, despite reportedly higher bone mineral density (BMD). The purpose of this study was to use an engineering beam analysis to calculate and compare the load stresses on the femurs of healthy women and women with T2DM and compare these levels to conventional measures of femoral neck BMD.
MATERIALS/METHODS: We studied 3658 women who participated in the Canadian Multicentre Osteoporosis Study (CaMos), and who had available Hip Structure Analysis (HSA) data from baseline dual energy x-ray absorptiometry (DXA) scans. Women were categorized into two groups based on the presence or absence of self-reported T2DM. We computed stress in megapascals (MPa) at the infero-medial margin of the femoral neck in a one-legged stance using an engineering beam analysis incorporating dimensions and geometry from DXA scans using the HSA method. We used linear regression (SAS 9.3) to determine the association between T2DM status and stress. We also determined the association between T2DM status and femoral neck BMD.
Stresses were 4.5% higher in T2DM women than in non-diabetics (11.03±0.18 vs. 10.56±0.04 MPa; p=0.0093). Femoral neck BMD was 4.2% greater in women with T2DM than in non-diabetics (0.74±0.002 vs. 0.71±0.01 g/cm(2); p=0.0008).
Despite higher femoral neck BMD, higher stress indicates weaker skeletal geometry for a given load, and suggests an impaired skeletal adaptive response to load may be present in women with T2DM.
最近的数据表明，2 型糖尿病（T2DM）女性可能更容易骨折，这是由于机械负荷的适应性反应受损，尽管她们的骨密度（BMD）较高。本研究的目的是使用工程梁分析来计算和比较健康女性和 T2DM 女性股骨的负荷应力，并将这些水平与股骨颈 BMD 的常规测量值进行比较。
材料/方法：我们研究了 3658 名参加加拿大多中心骨质疏松症研究（CaMos）的女性，她们在基线双能 X 射线吸收法（DXA）扫描时均有髋部结构分析（HSA）数据。根据是否存在自我报告的 T2DM，将女性分为两组。我们使用工程梁分析，结合 DXA 扫描的尺寸和几何形状，在单腿站立时计算股骨颈下内侧边缘的压力（MPa），使用 HSA 方法。我们使用线性回归（SAS 9.3）来确定 T2DM 状态与压力之间的关联。我们还确定了 T2DM 状态与股骨颈 BMD 之间的关联。
T2DM 女性的压力比非糖尿病女性高 4.5%（11.03±0.18 与 10.56±0.04 MPa；p=0.0093）。T2DM 女性的股骨颈 BMD 比非糖尿病女性高 4.2%（0.74±0.002 与 0.71±0.01 g/cm2；p=0.0008）。
尽管股骨颈 BMD 较高，但较高的压力表明在给定负荷下骨骼几何形状较弱，这表明 T2DM 女性的骨骼对负荷的适应性反应受损。
