慢性肾脏病患者尿蛋白肌酐比与24小时尿蛋白定量的相关性研究

A study on the relationship between urinary protein-creatinine ratio and 24-hour urinary protein quantity in patients with chronic kidney disease

目的探讨晨尿、随机尿的尿蛋白肌酐比值(protein/creatinine ratio,PCR)与24 h尿总蛋白定量(24-hour urine total protein quantity,24 hUTP)之间的相关性及其预测方程。方法选取在武汉市第一医院肾内科就诊的慢性肾脏病(CKD)患者211例,对患者晨尿PCR、随机尿PCR与24 hUTP进行差异性及相关性分析。采用ROC曲线分析晨尿PCR、随机尿PCR预测24 hUTP的最佳临界点。采用多元线性回归方法建立晨尿PCR、随机尿PCR预测24 hUTP的方程。结果晨尿PCR、随机尿PCR与24 hUTP之间无明显差异(P=0.81);晨尿PCR与24 hUTP间存在显著正相关(r=0.90,P<0.01),随机尿PCR与24 hUTP间存在显著正相关(r=0.95,P均<0.01),随机尿PCR与24 hUTP间的相关性高于晨尿。从性别、年龄、24 h尿量、病因、eGFR、Alb、总胆固醇水平方面对纳入患者进行分组,不同分组的晨尿PCR、随机尿PCR与24 hUTP间均存在显著正相关,且不同分组的随机尿PCR与24 hUTP的相关性均高于晨尿PCR。ROC曲线分析结果显示,以0.5 g、1.0 g、3.5 g作为24 hUTP的界点时,晨尿PCR预测24 hUTP的最佳临界值分别为0.70 g/g(敏感性84.4%,特异性86.0%)、1.09 g/g(敏感性95.8%,特异性91.3)、3.81 g/g(敏感性66.7%,特异性89.9%);随机尿PCR预测24 hUTP的最佳临界值分别为0.56 g/g(敏感性93.5%,特异性75.4%)、1.11 g/g(敏感性98.3%,特异性92.4%)、3.43 g/g(敏感性87.9%,特异性89.9%)。晨尿PCR、随机尿PCR预测24 hUTP的方程分别为:①24 hUTP(g)=0.793+0.793×晨尿PCR+0.124×总胆固醇-0.177×Alb(决定系数R^2=0.87);②24 hUTP(g)=0.369+0.856×随机尿PCR+0.132×总胆固醇-0.092×Alb(决定系数R^2=0.92),随机尿的预测方程比晨尿更准确。结论晨尿PCR、随机尿PCR与24 hUTP均有良好的相关性,其相关性不受性别、年龄、24 h尿量、病因、eGFR、Alb、总胆固醇水平的影响,且随机尿PCR与24 hUTP间的相关性高于晨尿PCR。应用预测方程,可有效的评估CKD患者的预后及诊疗效果,建议使用随机尿PCR预测方程代替24 hUTP检测。

Objective To explore the correlation between urinary protein-creatine ratio(PCR)and 24-hour urinary total protein quantity(24 hUTP)in morning urine and random urine and its predictive equation.Methods A total of 211 patients with chronic kidney disease(CKD)visited to treat in Wuhan First Hospital were selected.The difference and correlation between PCR and 24 hUTP in morning urine and random urine were analyzed.ROC curve was used to analyze the PCR in morning urine and random urine to predict the optimal critical point of 24 h UTP.The equation for predicting 24 hUTP by PCR in morning urine and random urine was established by multiple linear regression method.Results There was no significant difference between PCR and 24 hUTP in morning urine and random urine(P=0.81),but there was a significant positive correlation between morning urine and random urine PCR and 24 hUTP(r=0.90,P<0.01),and there was also a significant positive correlation between PCR and 24 h UTP in random urine(r=0.95,mean P<0.01),which was higher than that in morning urine.The patients were divided into gender,age,24 h urine volume,etiology,eGFR,Alb,and total cholesterol level groups.A significant positive correlation between PCR and 24 h UTP in morning urine and random urine existed in various groups,with the higher correlation between PCR and 24 h UTP in random urine than that in morning urine.ROC curve analysis showed that,with 0.5 g/24 h,1.0 g/24 h and 3.5 g/24 h used as the critical point of 24 h UTP,the optimal critical point values of 24 h UTP predicted with PCR in morning urine were 0.70 g/g(sensitivity 84.4%,specificity 86.0%),1.09 g/g(sensitivity 95.8%,specificity 91.3%)and 3.81 g/g(sensitivity 66.7%,specificity 89.9%),respectively;those predicted with PCR in random urine,0.56 g/g(sensitivity 93.5%,specificity 75.4%).1.11 g/g(sensitivity 98.3%,specificity 92.4)and 3.43 g/g(sensitivity 87.9%,specificity 89.9%),respectively.The prediction equations of 24 h UTP obtained from PCR in morning urine and random urine were as follows:①24 hUTP(g)=0.793+0.793×PCR in morning urine+0.124×total cholesterol-0.177×serum albumin(determination coefficient R2=0.87);②24 hUTP(g)=0.369+0.856×PCR in random urine+0.132×total cholesterol-0.092×serum albumin(determination coefficient R^2=0.92).The prediction equation for random urine was more accurate that for morning urine.Conclusions There is a good correlation between PCR and 24 hUTP in morning urine and random urine.The correlation is not affected by gender,age,24 h urine volume,etiology,glomerular filtration rate,serum albumin and total cholesterol level.The correlation for random urine is higher than that for morning urine.The prediction equations can be used to evaluate the prognosis and diagnosis and treatment in patients with chronic renal disease.It is recommended that the prediction equation with PCR in random urine be an alternative method for detection of 24 h UTP.