Correlation Between Quantitative CT Measurement Of Bone Mineral Density In Patients With Chronic Kidney Disease

Objective To observe whether the Quantitative computed tomography(QCT)and dual-energy X-ray absorptiometry(DXA)in patients with chronic kidney disease(CKD)are consistent,and to explore the value of QCT in the diagnosis of osteoporosis in patients with CKD.To explore t the relationship between bone mineral density and clinical data and serological markers in patients with CKD,and to explore the risk factors of bone mineral density reduction in patients with CKD.Methods A total of 102 patients with CKD admitted to the Department of Nephrology,Qingdao Municipal Hospital from January 2018 to December 2018 were enrolled.The bone mineral density of the lumbar spine,total hip and femoral neck were measured by QCT and DXA.The basic clinical data such as gender,age,height,weight,history of diabetes were collected,and serological indicators such as serum creatinine(Scr),blood urea nitrogen(BUN),serum albumin(ALB),alkaline phosphatase(AKP),and total calcium(Ca),serum phosphorus(P),low density lipoprotein(LDL),blood uric acid,Intact parathyroid hormone(iPTH)were collected.Body mass index(BMI),estimated glomerular filtration rate(eGFR),and corrected calcium were calculated according to the formula.According to the bone mineral density measured by the two methods,the consistency of QCT and DXA osteoporosis diagnosis and the sensitivity and specificity of QCT diagnosis of osteoporosis were analyzed.The difference of bone mineral density measured by QCT under different stages and genders was statistically analyzed.And the correlation between bone mineral density and serological indicators,and risk factors for bone mineral density reduction in patients with CKD were analyzed.Results 1.The average age of 102 patients with CKD was 59.99±13.21 years old,including 55 males(aged 32-83 years old,average 59.51 years old)and 47 females(age34-84 years old,average 58.38 years old).There were 28,24,24,and 26 patients with CKD 1 to 2,3,4,and 5,respectively.2.After paired chi-square test,c~2=5.00,P=0.172,Kappa value was 0.893 in lumbar vertebrae,c~2=1.143,P=0.767,Kappa value was 0.822 in total hip,c~2=4.800,P=0.091,Kappa value was 0.860 in femoral neck were calculated respectively.QCT and DXA have diagnostic consistency.3.In the lumbar vertebrae,total hip,femoral neck,the area under the ROC curve of QCT diagnosis of bone density reduction was 0.975,0.947,0.981,respectively.The sensitivity was 90.70%,90.48%,91.53%,and the specificity was 98.31%,92.31%,97.67%,respectively.4.The mean bone mineral density of patients with CKD stage 4 and CKD stage 5 was lower than that of the control group.There was no significant difference in bone mineral density between the CKD stage 1 and stage 2 and the CKD stage 3 group.5.All CKD patients were divided into two groups by gender.In 55 males,the bone mineral density of lumbar vertebrae,total hip and femoral neck measured by QCT were 11.01±27.98,-0.43±1.29,and-0.45±1.30,respectively.In 47 women,the bone mineral density of lumbar vertebrae,total hip and femoral neck measured by QCT were 97.16±26.24,-1.18±1.41,-1.01±1.39.There were significant differences in bone mineral density between male and female in three different parts(P<0.05).6.All CKD patients were divided into two groups according to whether or not diabetes.The bone mineral density values of lumbar vertebrae,total hip and femoral neck of 48 patients with diabetes mellitus by QCT are106.96±25.67,-0.76±1.36,-0.73±1.28,respectively.The bone mineral density values of lumbar vertebrae,total hip and femoral neck of 54 patients without diabetes mellitus by QCT are 102.01±30.34,-0.79±1.43,-0.68±1.48.There were no significant differences in bone mineral density between the two groups(P>0.05).7.In all patients with CKD,bone mineral density was associated with age,BMI,eGFR,BUN,creatinine,AKP,iPTH,and had no significant correlation with albumin,Ca,P,corrected calcium,low density lipoprotein,uric acid.8.Multiple logistic regression analysis revealed,age and female are independent risk factors for bone mineral density reduction.BMI is a protective factor in lumbar and total hip bone density analysis.Conclusion In patients with CKD,the bone mineral density measured by QCT and DXA are consistent in the diagnosis of osteoporosis and low bone mass,and the sensitivity and specificity are good.QCT has a certain value for detecting bone mineral density in patients with CKD.Age and female are independent risk factors for bone mineral density in patients with chronic kidney disease,,and BMI is a protective factor of bone mineral density.