The values of estimated glomerular filtration rate calculated with creatinine and cystatin C based equations in healthy adults

The glomerular filtration rate (GFR) is widely accepted as the best overall index of kidney function. GFR can be measured as the clearance of exogenous or endogenous filtration markers or clinically estimated from serum concentrations of creatinine or cystatin C. Recently, it has been recommended that an estimated GFR (eGFR) should be reported in addition to the value of filtration markers. In this study, we determined the values of eGFR, based on creatinine and cystatin C equations, in 125 healthy volunteers aged 20-75 years. Creatinine was measured by a kinetic alkaline picrate method on an ARCHITECT ci8200 analyzer (Abbott Diagnostics, Wiesbaden, Germany). Cystatin C was determined by a latex particle-enhanced immunonephelometric assay (BNII, Dade Behring, Marburg, Germany). The eGFR values were calculated for creatinine using the Modification of Diet in Renal Disease (MDRD) study equation and Rule's quadratic equation and for cystatin C according to the equation published by Hoek et al. The reference intervals for eGFRs with MDRD, Rule's quadratic and Hoek's equations were calculated nonparametrically and were determined to be 63.5-124.6 mL/min/1.73 m2, 78.3-139.2 mL/min/1.73 m2 and 72.2-115.6 mL/min/1.73 m2, respectively. According to the US National Kidney Foundation, chronic kidney disease (CKD) can be defined as a GFR < 60 mL/min/1.73 m2. Our results showed that healthy adults had eGFR values > 63.5 mL/min/1.73 m2. However, it is important to note that these normal values overlap with values in stages 1 and 2 of CKD, thus an eGFR greater than 60 mL/min/1.73 m2 does not exclude kidney disease.     

肾脏MR表观扩散系数与估算肾小球滤过率的关系

目的探讨肾脏扩散加权成像(diffusion weighted imaging,DWI)所测量表观扩散系数(apparent diffusion coefficient,ADC)值与估算肾小球滤过率(estimated glomerular filtration rate,eGFR)之间的关系。材料与方法 2013年1月至2015年5月,武汉大学人民医院627例受试者在3.0 T磁共振扫描仪上行肾脏扩散加权成像。根据eGFR的不同将受试者分为3组,即eGFR30 m L/min/1.73m~2组、30 mL/min/1.73m~2≤e GFR60 m L/min/1.73m~2组以及eGFR≥60 m L/min/1.73m~2组。测量肾门水平肾皮髓质交界区的ADC值。比较3组间ADC值的差异并分析ADC值与eGFR的相关性。结果 3组肾脏的平均ADC值分别为(1.72±0.10)×10~(-3) mm~2/s、(1.88±0.16)×10~(-3) mm~2/s、(1.90±0.16)×10~(-3) mm~2/s。3组肾脏ADC值间差异具有统计学意义(F=81.24,P0.001)。肾脏ADC值与eGFR之间有显著相关性(r=0.613,P0.05)。结论 ADC值的测量能在一定程度上反映患者肾脏滤过功能,DWI对肾功能的评价具有重要价值。     

Applicability of estimated glomerular filtration rate in stratifying chronic kidney disease

OBJECTIVE: The aim of this audit was to evaluate the degree of glomerular filtration rate (GFR) among inpatients and outpatients in a District General Hospital, with special attention given to laboratory testing and impact on health delivery. BACKGROUND: UK Chronic Kidney Disease guidelines recommend that investigation of renal function should be accompanied by an estimation of GFR (eGFR) in order to identify and manage patients with chronic kidney disease (CKD). The estimated GFR forms the basis for classification of CKD and appropriate action plans for patient management and follow-up. METHOD: A retrospective audit of 8160 results from a predominantly British Caucasian population was carried out; extracting creatinine results from two isolated months in years 2001 and 2004. The estimated GFR (eGFR) was calculated using the MDRD formula. The data were classified according to demography, serum creatinine and eGFR. Patients from the 2001 database were classified according to eGFR and those with a value of <60 mL/min/1.73 m(2) were followed up in 2004. RESULTS: The difference in eGFR between the men and women was significantly different with medians (confidence intervals) of 80.1 (41-109) and 64.4 (30-84.6) (p<0.0001), respectively. There was an inverse association between age and eGFR in both genders (p<0.0001), with a decrease in eGFR of around 7 % for each decade increase in age. 1926 patients (24 %) of results studied had eGFR <60 mL/min, of whom 64 % were females and 36 % males. Follow-up of patients with eGFR<60 mL/min from 2001 showed that 4 % progressed to stages 4 and 5 CKD. CONCLUSION: eGFR is inversely associated with increasing age and female gender. MDRD derived eGFR fails to completely compensate for age and gender variations and thus different action limits may be required. Small but significant numbers of patients progressed to stages 4 and 5 CKD. Additional clarity in describing "progressive fall in eGFR" in the guidelines would improve identification of the population most at risk.     

A new tool for predicting the probability of chronic kidney disease from a specific value of estimated GFR

Abstract

Objective. To demonstrate how patients’ probability of having chronic kidney disease (CKD) stage 3–5 (measured GFR <60 mL/min/1.73 m²) can be predicted from a specific value of estimated glomerular filtration rate (eGFR). Material and methods. The probability of CKD stage 3–5 was predicted from a logistic regression model (n = 850) using three different eGFR prediction equations: Lund-Malmö, MDRD and CKD-EPI. Population weighting was used to illustrate how this probability varies in three different populations: original sample (55% true prevalence of CKD stage 3–5), a screening (6.7% prevalence) and a CKD population (84% prevalence). Results. All three eGFR-equations had high classification ability (area under the receiver-operating-characteristic curve = 97%). The probability of CKD stage 3–5 increased with decreasing eGFR, varied substantially among the populations studied and to some extent between the eGFR-equations. Using the Lund-Malmö equation as illustration, the probability of CKD stage 3–5 is > 90% only when eGFR is <38 mL/min/1.73 m² in a screening population, whereas it is > 90% already when eGFR is <51 mL/min/1.73 m² in a CKD population. Conversely, the probability of CKD stage 3–5 is <10% if eGFR > 59 mL/min/1.73 m² in a screening population, whereas it is <10% only when eGFR is > 88 mL/min/1.73 m² in a CKD population. Conclusion. Instead of reporting diagnostic accuracy as sensitivity, specificity, and predictive values, actual eGFR supplemented with the probability that it represents a true GFR <60 mL/min/1.73 m² may be more valuable for physicians. Clinical (pre-test) probability in the population must be considered when predicting this probability.     

糖尿病患者肾小球滤过率评估方法的临床应用研究

目的探讨适用于2型糖尿病患者肾脏功能评估的肾小球滤过率(GFR)估算公式,比较简化肾脏病膳食改善试验(MDRD)、推荐的肾脏病膳食改善试验(rMDRD)、慢性肾脏病流行病学协作组(CKD-EPI)和半胱氨酸蛋白酶抑制剂C(Cys C)相关GFR 4个GFR估算公式的实际应用。方法收集178例2型糖尿病患者的相关资料,检测血清肌酐(SCr)及Cys C浓度,同时行同位素99m锝-二乙三胺五乙酸(99mTc-DTPA)肾动态显像,得出同位素GFR(iGFR),并以此作为GFR的参考标准。依据美国糖尿病协会(ADA)标准将178例患者分成3个亚组[GFR 15～59、60～89、≥90 mL/(min·1.73 m2)],对各公式的GFR估算值(eGFR)与iGFR进行配对t检验、相关分析、Bland-Altman分析、受试者工作特征(ROC)曲线及15%、30%、50%符合率比较。结果 MDRD公式应用于GFR<60 mL/(min·1.73 m2)的患者,其eGFR与iGFR相关性较好,符合率较高,偏差无统计学意义;应用于GFR≥60 mL/(min·1.73 m2)的患者,其eGFR与iGFR差异有统计学意义(P<0.001)。rMDRD公式计算eGFR在准确性、诊断效能等方面与MDRD公式无明显差异。CKD-EPI公式应用于GFR≥90 mL/(min·1.73 m2)的患者,其eGFR与iGFR的符合率高于MDRD和rMDRD;应用于GFR 60～89 mL/(min·1.73 m2)的患者时,其符合率低于Cys C GFR公式。Cys C GFR公式得出的eGFR与iGFR的相关性、偏差、一致性及符合率均明显优于MDRD和rMDRD公式,尤其应用于GFR≥90 mL/(min·1.73 m2)的患者时,其eGFR与iGFR偏差无统计学意义,明显优于其他3个公式。结论 4个GFR估算公式均能准确估算GFR<60 mL/(min·1.73 m2)的2型糖尿病患者的肾功能水平。在GFR≥90 mL/(min·1.73 m2)时,Cys C GFR公式明显优于传统以SCr为基础的GFR估算公式。     

Urinalysis in chronic kidney disease

Chronic kidney disease (CKD) is defined by glomerular filtration rate (GFR) below 60 mL/min/1.73 m2 and/or renal abnormalities including proteinuria and/or hematuria beyond 3 months. Urinalysis is an important screening test to find out CKD subjects earlier. In health check examination, proteinuria was detected in 2.3% of male population over 18 years old. The prevalence of lower estimated GFR below 50 mL/min/1.73 m2 increased to 8.9% of subjects with 1+ proteinuria and 31.8% of subjects with 2+ or more proteinuria as compared with 2.0% of subjects with negative proteinuria (p < 0.0001). To detect CKD stage IV or V, the sensitivity and the specificity of proteinuria were 0.68 and 0.978, respectively, and the positive likelihood was 30.9 (95% CI, 8.3-114.9, p < 0.0001).     

Applicability of estimated glomerular filtration rate in stratifying chronic kidney disease

Objective. The aim of this audit was to evaluate the degree of glomerular filtration rate (GFR) among inpatients and outpatients in a District General Hospital, with special attention given to laboratory testing and impact on health delivery. Background. UK Chronic Kidney Disease guidelines recommend that investigation of renal function should be accompanied by an estimation of GFR (eGFR) in order to identify and manage patients with chronic kidney disease (CKD). The estimated GFR forms the basis for classification of CKD and appropriate action plans for patient management and follow‐up. Method. A retrospective audit of 8160 results from a predominantly British Caucasian population was carried out; extracting creatinine results from two isolated months in years 2001 and 2004. The estimated GFR (eGFR) was calculated using the MDRD formula. The data were classified according to demography, serum creatinine and eGFR. Patients from the 2001 database were classified according to eGFR and those with a value of <60?mL/min/1.73m² were followed up in 2004. Results. The difference in eGFR between the men and women was significantly different with medians (confidence intervals) of 80.1 (41–109) and 64.4 (30–84.6) (p<0.0001), respectively. There was an inverse association between age and eGFR in both genders (p<0.0001), with a decrease in eGFR of around 7?% for each decade increase in age. 1926 patients (24?%) of results studied had eGFR <60?mL/min, of whom 64?% were females and 36?% males. Follow‐up of patients with eGFR<60?mL/min from 2001 showed that 4?% progressed to stages 4 and 5 CKD. Conclusion. eGFR is inversely associated with increasing age and female gender. MDRD derived eGFR fails to completely compensate for age and gender variations and thus different action limits may be required. Small but significant numbers of patients progressed to stages 4 and 5 CKD. Additional clarity in describing “progressive fall in eGFR” in the guidelines would improve identification of the population most at risk.     

简化肾脏病膳食改良试验公式在血清肌酐值正常的老年男性群体中的应用

目的：探讨血清肌酐（SCr）正常的老年男性人群SCr值与经肾脏病膳食改良试验（MDRD）公式估算的肾小球滤过率（GFR）的关系。方法：应用简化MDRD公式估算818名门诊体检、SCr正常的老年男性的GFR,将其按估算GFR值[GFR〈60mL/（min·1.73m^2）、60～89mL/（min·1.73m^2）、≥90mL/（min·1.73m^2）]进行分组,比较各组间年龄、体重、体重指数（BMI）、腰臀比（WHR）等,结果发现年龄、伴随疾病在不同GFR估算值组中的差异有统计学意义;再将体检者按年龄、伴随疾病分组,并应用线性回归及ROC曲线分析SCr值与GFR估算值的关系。结果：应用简化MDRD公式估算GFR发现,818名体检者中有53人（6.5%）GFR呈中度下降,均值为（57±2）mL/（min·1.73m^2）,他们平均年龄较大,为（79±6）岁,SCr值较高,为（112±6）μmol/L。按年龄分组中,SCr水平在60～69岁组与70岁以上组比较,差异有统计学意义（P〈0.05）;按伴随疾病及年龄分组,≥70岁的人群伴高血压合并2型糖尿病的患病率达39.2%,而60～69岁的人群则为15.0%。在无高血压、糖尿病高危因素的人群中,SCr值为109.5μmol/L时,经ROC曲线计算,诊断GFR异常的灵敏度为100%,误诊率为3.1%;合并高危因素人群（年龄≥70岁同时合并2型糖尿病、高血压）,SCr值为108.5μmol/L时,诊断GFR异常的灵敏度为100%,误诊率为3.2%。结论：年龄≥70岁合并慢性肾脏疾病（CKD）高危因素（如高血压、2型糖尿病）的老年男性人群,当SCr值为正常高值时（108.5μmol/L）,采用MDRD公式估算的GFR可能有异常,本研究方法可用于早期筛查CKD患者。     

Estimated glomerular filtration rate (eGFRCystC) from serum cystatin C shows strong agreement with iohexol clearance in patients with low GFR

OBJECTIVE: Estimation of glomerular filtration rate (eGFR) is essential in the diagnosis and monitoring of patients with kidney disease and for correct dosage of drugs eliminated from the circulation by the kidneys. Cystatin C has been shown in several studies to be superior to creatinine in estimating eGFR. However, there are few studies on the performance of cystatin C estimated eGFR (eGFRCystC) in patients with advanced kidney disease and low GFR. MATERIAL AND METHODS: We measured serum cystatin C, together with serum creatinine, during iohexol clearance in patients with iohexol clearance below 30 mL/min/1.73 m2. The cystatin C values were used to calculate eGFRCystC using the formula eGFR (mL/min/1.73 m2) = 79.901*(cystatin C value in mg/L)-1.4389. RESULTS: There was good correlation between eGFRCystC and iohexol clearance (r = 0.88) in patients with iohexol clearance <30 mL/min/1.73 m2 and none of the patients had a difference between eGFRCystC and iohexol clearance exceeding 50 %. The Modification of Diet in Renal Disease (MDRD) equation and corrected MDRD eGFR showed a positive bias and weaker correlations with iohexol eGFR (MDRD = 5.32+1.22*iohexol clearance; corrected MDRD = 4.76+1.10*iohexol clearance; r = 0.59). For MDRD eGFR, 42 of 94 (44.7%) samples showed more than 50% difference to iohexol clearance. CONCLUSIONS: eGFRCystC is an efficient, practical and cost-effective alternative to iohexol clearance in patients with reduced GFR.     

Chronic kidney disease as a risk factor for vestibular dysfunction

Objectives: The aim of this study was to determine whether chronic kidney disease (CKD) is associated with vestibular dysfunction in a general population.

Methods: Of the total participants, 7,799 of participants were included in this study. The data collected from the participants during the health examination included an estimated glomerular filtration rate (eGFR) and balancing test results. Mild CKD was defined as an eGFR of 60–90 mL/min/1.73 m2 or an eGFR ≥ 90 mL/min/1.73 m2 with dipstick proteinuria (≥ 1+). Moderate CKD was defined as an eGFR of 45–59 mL/min/1.73 m2. Severe CKD was defined as an eGFR of 30–44 mL/min/1.73 m2. Very severe CKD was defined as an eGFR < 30 mL/min/1.73 m2.

Results: The number of participants with vestibular dysfunction was 268. Univariate and multivariate linear regression analyses showed that eGFR levels were inversely associated with the presence of vestibular dysfunction. Multivariate analysis revealed that those with moderate, severe, and very severe CKD had a 1.830-, 4.496-, and 6.055-fold increased risk of vestibular dysfunction, respectively, compared to the participants without CKD.

Conclusion: CKD was found to be associated with vestibular dysfunction in the general population. Therefore, the participants with CKD may be closely monitored for vestibular dysfunction.     

Accuracy diagrams: a novel way to illustrate uncertainty of estimated GFR

Most studies that validate GFR equations present accuracy results stratified by measured GFR (mGFR; diagnostic correctness) or by estimated GFR (eGFR; diagnostic predictiveness) only, without a clear distinction in interpretation. The accuracy of a GFR equation is normally reported in percent (e.g. P₃₀), but is often misinterpreted when stratified by eGFR. The aim of the study was to develop new accuracy measures and diagrams that allow straightforward interpretations and illustrations of the uncertainty in eGFR in clinical practice. We applied quantile regression to the distribution of estimation errors for two creatinine-based GFR equations, LM-REV and CKD-EPI, in a clinical cohort (n?=?3495) referred for GFR measurement (plasma clearance of iohexol). Measures of bias and precision and accuracy intervals (AIs) were expressed in mL/min/1.73?m². Diagrams with AIs were chosen as a novel way to present the error margin in eGFR at a pre-specified certainty level. It was shown that creatinine-based equations are still quite inaccurate in that large estimation errors could not be ruled out with satisfactory certainty. As an example, the 75% AI for the most accurate equation, LM-REV, was approximately?±10?mL/min/1.73?m² at eGFR?=?45?mL/min/1.73?m², whereas it ranged between ?13 and +20?mL/min/1.73?m² at eGFR?=?90?mL/min/1.73?m². Accuracy intervals presented in diagrams can be used to illustrate the uncertainty of eGFR. Future validation studies should assess the variability in the predictiveness of eGFR across populations and clinical settings using tools and performance measures that are easy to interpret.     

How reliable is estimation of glomerular filtration rate at diagnosis of type 2 diabetes?

OBJECTIVE: The Cockcroft-Gault (CG) and Modification of Diet in Renal Disease (MDRD) equations previously have been recommended to estimate glomerular filtration rate (GFR). We compared both estimates with true GFR, measured by the isotopic (51)Cr-EDTA method, in newly diagnosed, treatment-na?ve subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 292 mainly normoalbuminuric (241 of 292) subjects were recruited. Subjects were classified as having mild renal impairment (group 1, GFR <90 ml/min per 1.73 m(2)) or normal renal function (group 2, GFR >/=90 ml/min per 1.73 m(2)). Estimated GFR (eGFR) was calculated by the CG and MDRD equations. Blood samples drawn at 44, 120, 180, and 240 min after administration of 1 MBq of (51)Cr-EDTA were used to measure isotopic GFR (iGFR). RESULTS: For subjects in group 1, mean (+/-SD) iGFR was 83.8 +/- 4.3 ml/min per 1.73 m(2). eGFR was 78.0 +/- 16.5 or 73.7 +/- 12.0 ml/min per 1.73 m(2) using CG and MDRD equations, respectively. Ninety-five percent CIs for method bias were -11.1 to -0.6 using CG and -14.4 to -7.0 using MDRD. Ninety-five percent limits of agreement (mean bias +/- 2 SD) were -37.2 to 25.6 and -33.1 to 11.7, respectively. In group 2, iGFR was 119.4 +/- 20.3 ml/min per 1.73 m(2). eGFR was 104.4 +/- 26.3 or 92.3 +/- 18.7 ml/min per 1.73 m(2) using CG and MDRD equations, respectively. Ninety-five percent CIs for method bias were -17.4 to -12.5 using CG and -29.1 to -25.1 using MDRD. Ninety-five percent limits of agreement were -54.4 to 24.4 and -59.5 to 5.3, respectively. CONCLUSIONS: In newly diagnosed type 2 diabetic patients, particularly those with a GFR >/=90 ml/min per 1.73 m(2), both CG and MDRD equations significantly underestimate iGFR. This highlights a limitation in the use of eGFR in the majority of diabetic subjects outside the setting of chronic kidney disease.     

苦味酸法和酶法检测肌酐对肾小球滤过率预测公式效能的影响

目的 探讨应用苦味酸法和酶法检测肌酐对GFR评估方程适用性的影响.方法 选取2007-2009年华北(北京)、东北(大连)、华东(上海)、华中(长沙)4个区域三级甲等综合医院CKD患者176例.以双血浆法99m Tc-二乙三胺五乙酸(99mTc-DTPA)血浆清除率作为176例CKD患者的rGFR.使用4个不同厂家的酶法或苦味酸法肌酐试剂配套不同厂家自动生化分析仪分别测定患者血肌酐,同时应用体表面积( BSA)标化的Cockcroft-Gault方程(CG/BSA方程)、简化MDRD方程、校正至同位素稀释质谱法的简化MDRD方程(MDRD-IDMS方程)、CKD流行病学合作研究方程(CKD-EPI方程)及2个国内简化MDRD改良方程(课题组方程1、2)分别计算eGFR,比较不同估算结果与rGFR的相关性、偏差、精密度以及30％准确性.结果 176例CKD患者的rGFR为[40.70(19.41～84.35)] ml·min-1·(1.73 m2)-1.应用苦味酸法测定肌酐时,各方程评估的eGFR与rGFR的ICC在0.879～0.923之间;应用酶法测定肌酐时,各方程评估的eGFR与rGFR的ICC在0.925 ～0.946之间,相关性优于应用苦味酸法测定肌酐.Bland-Altman图显示,各方程评估的eGFR在高值区偏差较大,但用酶法时偏离程度均小于应用苦味酸法.在rGFR≥60 ml·min-1·(1.73 m2)-1时,各方程应用酶法测定肌酐时的30％准确性在68.3％～90.0％之间,应用苦味酸法30％准确性在41％～75％之间,除课题组方程1外,其他方程应用酶法测定肌酐时的准确性均显著高于苦味酸法.而rGFR＜60ml· min-1·(1.73 m2)-1时,应用酶法、苦味酸法测定肌酐的30％准确性分别在39.7％～49.1％、40.5％～52.6％之间.对于同一方程,应用酶法测定肌酐的两套不同检测系统间,其30％准确性差异无统计学意义,而应用苦味酸法的两套不同检测系统间,其30％准确性差异有统计学意义.结论 同一评估方程使用苦味酸法和酶法两种不同的肌酐检测方法时,结果存在显著性差异.采用酶法测定肌酐时,方程评估的eGFR结果在相关性、偏离程度、准确性方面均优于苦味酸法.     

Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation pronouncedly underestimates glomerular filtration rate in type 2 diabetes

OBJECTIVE To evaluate the performance of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation to estimate glomerular filtration rate (GFR) in type 2 diabetic patients with GFR >60 mL/min/1.73 m(2). RESEARCH DESIGN AND METHODS This was a cross-sectional study including 105 type 2 diabetic patients. GFR was measured by (51)Cr-EDTA method and estimated by the MDRD and CKD-EPI equations. Serum creatinine was measured by the traceable Jaffe method. Bland-Altman plots were used. Bias, accuracy (P30), and precision were evaluated. RESULTS The mean age of patients was 57 ± 8 years; 53 (50%) were men and 90 (86%) were white. Forty-six (44%) patients had microalbuminuria, and 14 (13%) had macroalbuminuria. (51)Cr-EDTA GFR was 103 ± 23, CKD-EPI GFR was 83 ± 15, and MDRD-GFR was 78 ± 17 mL/min/1.73 m2 (P < 0.001). Accuracy (95% CI) was 67% (58-74) for CKD-EPI and 64% (56-75) for MDRD. Precision was 21 and 22, respectively. CONCLUSIONS The CKD-EPI and MDRD equations pronouncedly underestimated GFR in type 2 diabetic patients.     

Discontinuation of Angiotensin Converting Enzyme Inhibitors and Angiotensin Receptor Blockers in Chronic Kidney Disease

ObjectiveTo assess the patterns of angiotensin converting enzyme inhibitors and angiotensin receptor blockers (ACE-I/ARB) discontinuation in the setting of chronic kidney disease (CKD) progression in real-world clinical practice.Patients and MethodsWe identified incident ACE-I/ARB users with a baseline estimated glomerular filtration rate (eGFR) ≥15 mL/min/1.73 m² and without end-stage renal disease in the Geisinger Health System between January 1, 2004, and December 31, 2015. We investigated the associations of CKD stage, hospitalizations with and without acute kidney injury (AKI), serum potassium, bicarbonate level, thiazide, and loop diuretic use with ACE-I/ARB discontinuation.ResultsAmong the 53,912 ACE-I/ARB users, the mean age was 59.9 years, and 50.6% were female. More than half of users discontinued ACE-I/ARB within 5 years of therapy initiation. The risk of ACE-I/ARB discontinuation increased with more advanced CKD stage. For example, patients who initiated ACE-I/ARB with CKD stage G4 (eGFR: 15-29 mL/min/1.73 m²) were 2.09-fold (95% CI, 1.87-2.34) more likely to discontinue therapy than those with eGFR ≥ 90 mL/min/1.73 m². Potassium level greater than 5.3 mEq/L, systolic blood pressure ≤ 90 mm Hg, bicarbonate level < 22 mmol/L, and intervening hospitalization—particularly AKI-related–were also strong risk factors for ACE-I/ARB discontinuation. Thiazide diuretic use was associated with lower risk, whereas loop diuretic use was associated with higher risk of discontinuation.ConclusionIn a real-world cohort, discontinuation of ACE-I/ARB was common, particularly in patients with lower eGFR. Hyperkalemia, hypotension, low bicarbonate level, and hospitalization (AKI-related, in particular) were associated with a higher risk of ACE-I/ARB discontinuation. Additional studies are needed to evaluate the risk–benefit balance of discontinuing ACE-I/ARB in the setting of CKD progression.     

A new serum cystatin C-based equation for assessing glomerular filtration rate in liver transplantation

BACKGROUND: Cystatin C (CysC) has been identified to be an alternative marker of glomerular filtration rate (GFR), but no CysC-based equation has been developed for patients receiving liver transplantation. METHODS: Serum CysC and (99m)Tc-DTPA clearance (true GFR) were measured simultaneously on post-transplant days 1, 4 and 7. A new equation was constructed based on an observation group of 30 patients and its predictive ability was compared with three other CysC-based equations (Hoek, Filler and Larsson) based on a validation group of 30 patients. RESULTS: The new equation for calculating GFR was defined as 19.12+96.21x(1/CysC) and the derived GFR was estimated at 97.4+/-30.2 mL/min/1.73 m(2) and was close to the true GFR (96.8+/-32.8 mL/min/1.73 m(2)). Estimates of GFR by Hoek, Filler and Larsson formulas (61.4+/-25.4, 73.8+/-31.9 and 61.3+/-29.6mL/min/1.73 m(2), respectively) differed significantly from the true GFR. Correlation between the true GFR and all formulas showed no significant difference. Bias was neglectable for the new equation (mean difference: 0.6 mL/min/1.73 m(2)) but remarkable for the other three equations (mean difference: -22.9 to -35.4 mL/min/1.73 m(2)). Accuracy within 10%, 30% and 50% of the true GFR for the new equation (30.0%, 76.7% and 93.3%) was significantly higher than those of the other three equations (p<0.001 for all). CONCLUSIONS: A new serum CysC-based equation was established in this study and it was shown to be accurate in estimating GFR after liver transplantation, compared to the formulas of Hoek, Filler and Larsson.     

不同eGFR公式与ACR联合应用在肾功能损伤高危人群中的临床价值

目的探讨不同估算肾小球滤过率(eGFR)公式与尿白蛋白/肌酐比值(ACR)联合应用对高危人群肾功能损伤或早期肾功能降低的检出价值。方法收集850例慢性肾病(CKD)患者的临床资料,包括性别、年龄、身高、体质量、血清肌酐(SCr)、血清胱抑素C(Cys C)、ACR、血清尿素、血清尿酸(UA)、基于99m锝-二乙烯三胺五乙酸(99mTC-DTPA)肾动态显像法的测量肾小球滤过率(mGFR)及基础病史等。分别采用3种基于SCr的eGFR公式(CKD-EPI 2009SCr公式、简化MDRD方程和改良MDRD方程)、6种基于Cys C的eGFR公式(CKD-EPI 2012Cys C公式、Grubb公式、Arnal-Dade公式、Rule公式、Macisaac公式、Tan公式)和1种基于Cys C、SCr联合检测的eGFR公式(CKD-EPI 2012SCr-Cys C公式)计算eGFR。采用Spearman相关分析评估不同eGFR结果之间及与mGFR之间的相关性。采用Bland-Altman一致性分析评价eGFR与mGFR的一致性。结果男、女性CKD患者基于SCr的eGFR水平均高于mGFR(P<0.01),基于Cys C的eGFR水平均低于mGFR(P<0.01)。基于SCr的eGFR结果之间、基于Cys C的eGFR结果之间以及各eGFR结果与mGFR之间均呈正相关(P<0.01)。基于SCr的3种eGFR公式计算出的eGFR与mGFR的平均偏差为-4.2~-20.8 mL/(min·1.73 m2),高估了患者的肾小球滤过率(GFR);基于Cys C的6种eGFR公式计算出的eGFR与mGFR的平均偏差为3.7~16.9 mL/(min·1.73 m2),低估了患者的GFR;基于SCr与Cys C联合检测的eGFR公式计算出的eGFR与mGFR的平均偏差为9.6 mL/(min·1.73 m2),低估了患者的GFR。对于eGFRCKD-EPI 2009SCr漏检的G2期患者,eGFRMacisaac和ACR可分别检出79.2%和55.8%的患者,二者联合应用可检出87.7%的患者;对于eGFRCKD-EPI 2009SCr漏检的G3期~G5期患者,eGFRMacisaac和ACR可分别检出43.3%和61.1%的患者,二者联合使用可检出73.3%的患者。在G2期患者中,eGFRCKD-EPI 2009SCr、eGFRMacisaac和ACR联合应用可将检出率提高至94.4%;在G3期~G5期患者中,可提高至91.7%。结论eGFRCKD-EPI 2009Scr、eGFRMacisaac和ACR联合应用可以显著提高高危人群中肾功能损伤及早期肾功能下降者的检出率。     

Serum hepatocyte growth factor levels in patients with chronic renal disease--effect of GFR and pathogenesis.

Hepatocyte growth factor (HGF) is a growth-promoting peptide that appears to act in a renotropic and nephroprotective manner during acute renal damage. Recent studies suggest that HGF is also of importance in chronic renal diseases. The serum HGF level is correlated with serum creatinine, and it has been suggested that glomerular and tubular diseases affect serum HGF differently. In the present study. levels of serum HGF were determined and correlated to glomerular filtration rate (GFR) in 118 patients with various chronic renal diseases. GFR was determined by 99mTc-DTPA clearance, and the GFR values were evenly distributed in the interval 5-155 mL/min/1.73 m2. Serum HGF levels increased slightly with decreasing GFR: the Pearson correlation coefficient being 0.49 (p<0.0001). In 21 additional patients with end-stage renal disease treated with continuous ambulatory peritoneal dialysis, there was a more marked increase in the serum levels of HGF. The effect of glomerular and tubular diseases on serum HGF was examined by comparing the HGF levels in two groups of patients with similar GFR values: 57 patients with mainly glomerular disorders (diabetic nephropathy with micro- or macroalbuminuria or glomerulonephritis) and 14 patients with mainly tubular disorders (polycystic kidney disease). There was no significant difference between the HGF levels of the two groups (p=0.30). In conclusion: Serum HGF levels are correlated with GFR (for GFR > or = 5 mL/min/1.73 m2) in patients with chronic renal diseases, and glomerular and tubular disorders seem to affect the HGF level similarly.     

慢性肾脏病流行病合作工作组方程和肌酐全年龄段方程用于成人慢性肾脏病

目的 比较慢性肾脏病流行病合作组方程(CKD-EPI)和肌酐全年龄段方程(FAS)评估慢性肾脏病(CKD)患者肾小球滤过率(GFR)的价值.方法 回顾性分析393例CKD,以99Tcm-DTPA肾动态显像法所测GFR(Tc-GFR)为金标准,采用3个CKD-EPI方程及3个FAS方程,分别为流行病学-血肌酐(EPI-S...     

住院老年患者估算的肾小球滤过率与外周动脉疾病相关性研究

目的分析老年住院患者估算的肾小球滤过率(eGFR)与外周动脉疾病(PAD)之间的相关性。方法对693例年龄≥60岁老年住院患者进行横断面研究,收集患者心血管危险因素,测定血糖、糖化血红蛋白、血脂和肌酐(Cr)等生化指标,根据Cr计算eGFR诊断CKD;依eGFR水平将患者分为四组,正常组[eGFR≥90ml.min-1.(1.73m2)-1],轻度降低组[eGFR60～89ml.min-1.(1.73m2)-1],中度降低组[eGFR30～59ml.min-1.(1.73m2)-1],重度降低组[eGFR<30ml.min-1.(1.73m2)-1];测量踝臂指数(ABI),ABI≤0.95定义为PAD。结果 (1)与非CKD患者比较,CKD患者ABI值明显降低,分别为1.06(0.16)和1.00(0.28)(P<0.001);PAD患病率明显增高,分别为41.6%和22.2%(P<0.001)。(2)eGFR正常组至重度降低组,ABI值水平逐渐降低,分别为1.08(0.15)、1.05(0.16)、1.01(0.26)和0.88(0.41)(P<0.001);PAD患病率逐渐增加,分别为16.0%、23.9%、37.4%和61.5%(P<0.001)。相关分析显示ABI值与eGFR水平呈正相关(r=0.207,P<0.001)。(3)Logistic回归分析显示,调整性别、年龄和其他传统危险因素后,CKD患者PAD风险增加,危险比(95%可信区间)[OR(95%CI)]为1.680(1.135～2.486),四组不同eGFR水平分组中,eGFR重度降低增加PAD风险,OR(95%CI)为5.455(2.078～14.324),eGFR中度降低有增加PAD风险趋势,OR(95%CI)为2.045(0.971～4.308)(P=0.06)。结论 eGFR降低的老年患者ABI值下降和发生PAD的风险增加,并且这种风险随eGFR降低程度的加重而加重。