多种因素与定量CT测量老年髋部骨折患者骨密度的关系

A Factor Analysis of the Bone Mineral Density Detected by Quantitative CT in Elderly Cases with Hip Fracture

目的研究身高、体重、身体质量指数(BMI)及年龄、性别与定量CT (quantitative computed tomography,QCT)所测老年人髋部骨密度的关系。方法对93例因髋部骨折收治入院的患者行双能X线(DXA,dual-energy x-ray absorptiometry)及定量CT (QCT)扫描测量健侧髋部骨密度(BMD,bone mineral density)。年龄70~96岁,平均年龄(82.4±7.8)岁,其中男性21例,女性72例;股骨粗隆间骨折31例,股骨颈骨折62例。测量全髋、股骨颈、粗隆、粗隆间骨密度。采用Pearson相关分析QCT与DXA测量参数的相关性及多种因素与髋部骨密度的相关性,采用两独立样本t检验分析两种骨折以及两种性别之间参数的差异。结果 QCT所测量髋部各部位骨密度与传统DXA测量具有良好的相关性,身高、体重、BMI与QCT测量髋部骨密度均呈正相关,相关系数r分别为:0.357、0.366、0.259 (P均<0.05),决定系数r^2分别为0.134、0.134、0.063 (P均<0.05)。年龄与骨密度呈负相关,r=-0.324,决定系数r^2=0.105。进一步分析两种髋部骨折发现,股骨粗隆间骨折患者年龄偏大(P<0.05),且老年女性骨密度较男性低(P<0.05)。结论体重、身高、BMI、年龄及性别均为老年髋部骨密度的影响因素。尤其应重视体格瘦小的老年女性的骨质疏松的预防和诊断。

Objective To investigate the correlation between the bone mineral density(BMD) of hip detected by quantitative computed tomography(QCT) and various factors,including height,body weight,body mass index(BMI),age,sex,in the elderly with hip fracture.Methods Dual-energy X-ray absorptiometry(DXA) and quantitative computed tomography(QCT) were performed on 93 elderly(21 males and 72 females) with hip fractures to measure the BMI of the unaffected hip;the cases aged from 70 to 96 years old with the average of(82.4±7.8) years;out of the 93 elderly,there were 31 cases with intertrochanteric fractures and 62 cases with femoral neck fracture;the parameter of BMD including the region of total hip,femoral neck,greater trochanter and the intertrochanteric region were measured;Pearson correlation analysis was applied in analyzing the correlation between QCT and DXA parameters and in analyzing the correlation between the hip BMD and the various factors while independent sample T-test in analyzing the differences between the 2 fractures and between genders.Results The BMD measured by QCT was well correlated with the BMD measured by DXA;the factors including height,body weight and BMI were in positive correlation with the hip BMD measured by QCT,the correlation coefficient r were 0.357,0.336,0.259 respectively(P<0.05) and the coefficient of determination r2 were 0.134,0.134 and 0.063 respectively(P<0.05);age was in negative correlation with BMD(r=-0.324,r^2=0.105);further analysis indicated that cases with intertrochanteric fractures were older(P<0.05) and the BMD of the female was lower than that of the male(P<0.05).Conclusions Body weight,height,BMI,age and gender are the influencing factors of hip BMD in the elderly;more attention should be paid to the prevention and diagnosis of osteoporosis in the thin and small elderly women.