Abstract: Background　 The commonly accepted diagnostic criteria for osteoporosis are based on the results of dual energy X-ray absorptiometry（DXA）．Most of the measurement sites are waist and hip，and the T score is used to diagnose osteoporosis.However，there are few studies on the difference of T score between different sites and its clinical significance.Objective　To study the consistency of T score of dual-energy X-ray absorptiometry（DXA） in different sites of the body over 50 years and to analyze the difference of T score in different sites and its clinical significance.Methods　 The data of 6 945 individuals who underwent routine physical examination and DXA examination at the Physical Examination Center of the First Affiliated Hospital of Anhui Medical University were collected and calculated.The individuals were devided into groups by age，the data of bone mineral density（BMD） in the population was used as a reference value.On this basis，the T scores of L1~4，L2~4，femoral neck and total hip of male and female patients over 50 years were calculated.Results　The peak BMD of male was in the 20~age group，while that of female was in the 30~age group.There were no significant differences in L1~4 and L2~4 T scores among male over 50 years（P>0.05），the T scores of femoral neck and total hip in each age group were lower than that of L1~4 and L2~4，and the T score of total hip was higher than that of femoral neck（P<0.05）．There were no significant differences in L1~4 and L2~4 T scores among different age groups（P>0.05）；T score of femoral neck in 60~age group was lower than that in 50~age group，T score of femoral neck in 70~age group was lower than that in 60~age group and 50~age group，T score of total hip in 70~age group was lower than that in 50~age group，T score of femoral neck and total hip in 80~age group was lower than that in 70~age group，60~age group and 50~age group（P<0.05）．The T score of L1~4 was lower than that of L2~4 among female over 50 years（P<0.05）．In 50~age group and 60~age group，the T score of L1~4 and L2~4 was lower than that of femoral neck and total hip，but T-value of femoral neck in 70~age group and the T score of L1~4 and L2~4 in 80~age group，was higher than that of femoral neck and total hip（P<0.05）．The T score of femoral neck in 50~age group，60 ~ age group and 70~age group was lower than that of total hip（P< 0.05），except for 80~age group.In terms of L1~4 and L2~4 T scores among different age groups，60~，70~ age group was lower than 50~ age group，80~age group was lower than 60~age group and 50~ age group，the difference was statistically significant（P<0.05）．In terms of femoral neck and total hip T scores among different age groups，60~ age group was lower than 50~ age group，70~age group was lower than 60~age group and 50~age group，80~ age group was lower than 70~ age group，60~ age group and 50~age group，the difference was statistically significant（P<0.05）．Conclusion　Among men over 50 years，T scores of different sites are different，and hip is more significant in the diagnosis of osteoporosis；among womenover 50 years，T scores of different sites are different，the diagnosis of osteoporosis should be made by DXR in lumbar spine and hip in people below 70 years，and hip is a more suitable site in people over 70 years.Considering the difference of T value in different parts of different ages, we should select the appropriate location for evaluation.

Key words: Osteoporosis, Bone density, Dual-energy X-ray absorptiometry, T score, Over 50 years

摘要： 背景　目前公认的骨质疏松症诊断标准是基于双能X线吸收检测法（DXA）的测量结果，测量部位多为腰部和髋部，并以T值的高低进行骨质疏松症的诊断，但不同部位T值差异及其临床意义的相关研究较少。目的　研究50岁以上人群不同部位DXA所测T值的一致性，分析不同部位T值的差异及临床意义。方法　收集2010—2017年在安徽医科大学第一附属医院体检中心接受常规体检且进行DXA骨密度（BMD）检查的6 945例受检者的数据。按年龄进行分组，以人群中峰值BMD作为参考值，在此基础上计算50岁以上男、女受检者的L1~4、L2~4、股骨颈、全髋T值。结果　男性各部位峰值BMD出现在20~年龄组，女性各部位峰值BMD出现在30~年龄组。50岁以上男性，各年龄组内L1~4、L2~4 T值比较，差异无统计学意义（P>0.05）；各年龄组内股骨颈、全髋T值低于L1~4、L2~4 T值，全髋T值高于股骨颈T值（P<0.05）；各年龄组间L1~4、L2~4 T值比较，差异无统计学意义（P>0.05）；60~年龄组股骨颈T值低于50~年龄组，70~年龄组股骨颈T值低于60~、50~年龄组，70~年龄组全髋T值低于50~年龄组，80~年龄组股骨颈、全髋部位T值低于70~、60~、50~年龄组（P<0.05）。50岁以上女性，各年龄组内L1~4 T值均低于L2~4 T值（P<0.05）；50~年龄组和60~年龄组内L1~4、L2~4 T值低于股骨颈、全髋部位T值，70~年龄组内股骨颈T值和80~年龄组内股骨颈、全髋部位T值低于L1~4、L2~4 T值（P<0.05）；除80~年龄组，50~、60~、70~年龄组内股骨颈T值低于全髋部位T值（P<0.05）。不同年龄组间L1~4、L2~4 T值比较，60~年龄组低于50~年龄组，70~年龄组低于50~年龄组，80~年龄组低于60~、50~年龄组（P<0.05）；不同年龄组间股骨颈及全髋部位T值比较，60~年龄组低于50~年龄组，70~年龄组低于60~、50~年龄组，80~年龄组低于70~、60~、50~年龄组（P<0.05）。结论　50岁以上男性中，不同部位T值有差异，腰椎部位易受多种因素影响，故髋部T值在骨质疏松症诊断中意义更大；50岁以上女性中，不同部位T值有差异，在70岁前应综合腰椎及髋部T值进行判断，70岁以后因腰椎T值的检测结果易受多种因素影响，髋部T值在骨质疏松症诊断中意义更大。应考虑不同年龄不同部位T值的差异，选择合适的检测部位进行评估。

关键词: 骨质疏松, 骨密度, 双能X线吸收检测仪, T值, 50岁以上