Establishment of BMD reference plots and determination of peak BMD at multiple skeletal regions in mainland Chinese women and the diagnosis of osteoporosis

Osteoporosis is a major public health problem, particularly in women. Bone mineral density (BMD) reference plot is a basic, and the peak BMD (PBMD) an important, parameter in the diagnosis of osteoporosis. In order to establish reference plots of BMD at multiple skeletal sites in Chinese women and improve the diagnostic accuracy for osteoporosis, we measured BMDs at several skeletal regions in 3,378 Chinese women, aged 5–96 years, using a dual-energy X-ray absorptiometry fan-beam bone densitometer. After determining that the cubic regression model best fit all skeletal regions, we utilized the curve-fitting to establish BMD reference plots and utilized the curve-fitting equation to calculate the highest BMDs at all skeletal regions using three different methods of calculation—actual PBMD (method A), PBMD of each 5-year age group (method B), and a cross-section of age (method C). When the three methods were compared, we found significant differences among them at the majority of skeletal regions studied. When we utilized these three methods to determine the prevalence of osteoporosis in 2,120 women aged 40 years and older, except for the Wards triangle, we observed significant differences among them at all skeletal regions. In the present study, we established new BMD reference plots at multiple skeletal regions for women of mainland China. Our findings also indicate that curve-fitting equations can be employed to calculate actual PBMDs specific to individual regions, and that the use of different methods to calculate PBMD may have a significant impact on both PBMD and the diagnosis of osteoporosis. Therefore, we suggest that a standardized method be established to calculate site-specific PBMDs based on the peak values of best-fit reference curves in appropriate age groups.     

女性不同骨骼部位骨密度峰值和参考图的建立方法

目的建立女性不同骨骼部位骨密度(BMD)参考图和确定峰值BMD(PBMD). 方法 用DXA QDR 4500A型扇形束骨密度仪测量3378例5～96岁女性腰椎前后位(AP)和仰卧侧位、髋部和前臂的BMD,用8种回归模型拟合BMD随年龄的变化,找出最佳拟合模型方程建立参考图和确定PBMD.结果三次回归模型拟合程度最佳,即方程的决定系数(R2)最大.我们应用拟合曲线建立了BMD参考图,拟合曲线方程计算各骨骼部位最高的BMD(A方法)和BMD最高的5岁年龄组(B方法)及年龄横断面(C方法)计算PBMD,发现在大多数骨骼部位,三种方法计算的PBMD的差异有显著性.结论此研究建立了女性不同骨骼部位BMD参考图.应用拟合曲线方程计算PBMD(A方法)可获得符合骨骼部位特异性的真正的PBMD,不同方法计算PBMD将对PBMD和诊断骨质疏松产生严重影响.     

中国长沙地区女性多骨骼部位骨密度参考值横断面调查

目的 横断面调查中国长沙地区女性多骨骼部位骨密度（BMD）随年龄的变化，建立诊断骨质疏松症（OP）参考数据库。方法 用DXA QDR－4500A型扇形束骨密度仪测定2702例5－96岁女性腰椎前后位（AP）和仰卧侧位、髋部及前臂38个不同区域的BMD。结果 按每5岁年龄分组分析的结果显示，38个不同骨骼区域的峰值BMD分别出现在20－24岁至40－44岁之间，其中髋部（股骨颈除外）最早（20－24岁），前臂（超远端除外）最晚（40－44岁）。结论 不同骨骼区域峰值BMD出现的年龄各异。     

The vitamin D analogue 2MD increases bone turnover but not BMD in postmenopausal women with osteopenia: Results of a 1‐year phase 2 double‐blind,placebo‐controlled,randomized clinical trial

Most osteoporosis drugs act by inhibiting bone resorption. A need exists for osteoporosis therapies that stimulate new bone formation. 2‐Methylene‐19‐nor‐(20S)‐1α,25‐dihydroxyvitamin D₃ (2MD) is a vitamin D analogue that potently stimulates bone formation activity in vitro and in the ovariectomized rat model. In this randomized, double‐blind, placebo‐controlled study of osteopenic women, the effect of daily oral treatment with 2MD on bone mineral density (BMD), serum markers of bone turnover, and safety were assessed over 1 year. Volunteers were randomly assigned to three treatment groups: placebo (n = 50), 220 ng of 2MD (n = 54), and 440 ng of 2MD (n = 53). In general, 2MD was well tolerated. Although 2MD caused a marked increase in markers of bone formation, it did not significantly increase BMD. Since 2MD also shows marked activity on bone resorption (as revealed by dose‐dependent increases in serum C‐telopeptide cross‐links of type I collagen in this study), 2MD likely stimulated both bone formation and bone resorption, thereby increasing bone remodeling. © 2011 American Society for Bone and Mineral Research.