中国与美国多种族女性髋部骨量和丢失率的比较

Differences in age-related bone mass and bone loss rate of hip between Chinese women and women of different races in the USA

目的比较中国本土女性和美国不同种族女性与年龄相关的骨量及丢失率的差异。方法我们采用DXA骨密度仪测量3614例中国女性髋部各区域的骨密度（BMD）、体积骨密度（vBMD）、骨矿含量（BMC）和骨面积（BA），并与美国第三次国家健康和营养调查（NHANES Ⅲ）报告中的白人、黑人和美国墨西哥女性的资料比较。结果中国女性髋部各区域的BMD和BMC随年龄变化的拟合曲线均显著低于美国各种族女性（P=0．001—0．000）；黑人女性则始终处在最高水平（P=0．000）。在股骨颈，由BMD转换为vBMD表达时，中国女性与黑人的差异由22％缩小到18％，中国女性与白人的差异由7．4％缩小到0．8％，但白人和美国墨西哥人女性的差异由3．2％扩大到9．6％，白人与黑人女性的差异由13％扩大到17％。自人女性股骨颈和总体髋部的骨面积显著大于中国女性、美国墨西哥人和黑人女性（P=0．005～0．000）。到80岁时，各骨骼区域的累计骨丢失率，中国女性、美国墨西哥人、白人和黑人女性分别为-38．9％±1．8％，-34．4％±3．1％，-27．8％±5．9％和-28．4％±4．8％。结论中国本土女性髋部骨量显著低于美国非亚裔种族女性，而累计骨丢失率又显著大于美国非亚裔女性。在股骨颈，中国女性的vBMD与白人女性相似。

Objective To explore the differences in age-related bonemass and bone loss rate of the hip between native Chinese women and women of different races in the USA. Methods We measured bone mineral density （BMD）, volumetric BMD （vBMD）, bone mineral content （BMC） and bone area （BA） with DXA bone densitometer in different regions of hip in 3 614 Chinese women, aged 20 years and older. The best regression models were chosen to fit the changes of these parameters with increasing age, and the values of the fitting curves were determined by the Cartesian coordinate numeration system. Subsequently, we compared these fitting curves with the full-matched data of blacks, whites and Mexican-Americans women reported by the third National Health and Nutrition Examination Survey （ NHANES Ⅲ ）. Results We found that the fitting curves of BMD and BMC of Chinese women were significantly lower than those of women of races in America （ P = 0.001 - 0.000） ; and those of blacks women were highest among the four races（ P = 0.000）. However, when the expression of difference was transformed from BMD to vBMD at femoral neck, the difference between Chinese women and blacks women reduced from 22% to 18%, between Chinese women and whites women from 7.4% to 0.8%, but the difference enlarged from 3.2% to 9.6% between whites and Mexican-Americans, from 13% to 17% between whites and blacks women. The BAs of femoral neck and total femur of whites women were significantly larger than those of Chinese women, Mexican-Amerlcan and blacks women（P = 0.005 ～ 0.000）. By the age of 80 years, the accumulated bone loss rate （ABLR） in various regions of hip for Chinese women, Mexican-Americans, whites and blacks women were - 38.9% ± 1.8%, - 34.4% ±3.1%, - 27.8% ± 5.9% and - 28.4% ±4.8%, respectively. Conclusion The bone mass of native Chinese women in hip is significantly lower, and bone loss rate larger than those of non-Asian women in the USA. But at femoral neck, the vBMD of Chinese women is similar to that of white women.