应用MDRD公式与简化MDRD公式估测心力衰竭患者的肾小球滤过率水平

目的 探讨心力衰竭(HF)患者肾小球滤过率水平(GFR)和心功能分级的关系.方法 647例HF患者,分为急性左心衰患者和慢性心力衰竭(CHF)患者,后者按NYHA心功能分级分为Ⅰ、Ⅱ、Ⅲ、Ⅳ级,5组患者分别为18、31、200、253、145例;选取无心力衰竭的患者54例作为对照组.所有入选者抽血检查肝肾功能等项目,并根据肾脏病膳食改良试验(MDRD)公式及简化MDRD公式分别计算肾小球滤过率(eGFR).结果 2个公式所得出的eGFR水平在对照组、心功能Ⅱ级组、心功能Ⅰ级组、心功能Ⅲ级组、心功能Ⅳ级组、急性左心衰组中均逐渐降低.结论 肾小球滤过率水平与心力衰竭程度呈负相关,心力衰竭程度越重,肾小球滤过率水平越低.     

慢性心力衰竭不同分级的肾小球率过滤及同型半胱氨酸水平的观察分析

目的 通过观察分析慢性心力衰竭(CHF)不同分级的患者肾小球滤过率(GFR)水平及同型半胱氨酸(Hcy)水平,进一步探讨GFR及Hcy在心力衰竭患者中的临床意义.方法 收集CHF患者与对照组的病例资料,按照NYHA心功能分级分为Ⅰ、Ⅱ、Ⅲ、Ⅳ级,4组病例数分别为15、103、123、80例.选取无心力衰竭且年龄性别相当的患者30例作为对照组.记录血肌酐(SCr)和血尿素氮(BUN)、Hcy等指标.应用MDRD方程和简化MDRD方程来估算每个患者的肾小球滤过率(GFR).采用SPSS 15.0软件包进行统计学分析.结果 MDRD方程和简化MDRD方程计算出的GFR水平在对照组、心功能Ⅰ、Ⅱ、Ⅲ、Ⅳ级组中逐渐降低;MDRD方程和简化MDRD方程中的心功能Ⅰ、Ⅱ、Ⅲ、Ⅳ级组GFR水平,分别与对照组比较差异均有统计学意义(P＜0.05).对照组、心功能Ⅰ、Ⅱ、Ⅲ、Ⅳ级组中Hcy水平逐渐升高;心功能Ⅲ、Ⅳ级组Hcy水平,分别与对照组比较差异均有统计学意义(P＜0.05).结论 进一步验证了肾功能不全已经成为CHF患者死亡的一种独立的预测因素,GFR水平及Hcy水平检测可用来判定慢性心力衰竭患者的早期肾功能减退程度.     

肾功能受损对血清脑钠肽水平的影响

目的观察脑钠肽（brain natriuretic peptide,BNP）在慢性心力衰竭（chronic heart failure,CHF）不同分级时浓度的变化,以及与肾小球滤过率之间的关系。方法各种病因导致慢性心力衰竭患者500例,按NYHA心功能分级标准分为心功能Ⅰ级组、心功能Ⅱ级组、心功能Ⅲ级组和心功能Ⅳ级组,并且根据肾小球滤过率估测值（estimated glomerular filtration rate,eGFR）分为肾功能正常组和肾功能受损组,采用酶免疫法（ELISA）测定各组BNP浓度。结果CHF患者血浆BNP浓度随心功能级别变化,BNP水平增高,组间差异均显著（P〈O．01）;并且在同一心功能分级中,脑钠肽浓度随肾功能受损也出现了加重情况。结论血浆BNP水平是判断是否发生心力衰竭及其严重程度的可靠指标,当慢性心功能不全合并有肾功能受损时,体内的BNP水平会随着肾脏清除率的下降而升高。     

慢性心力衰竭患者肌钙蛋白Ⅰ水平与心功能分级的关系

目的：探讨慢性心力衰竭（CHF）患者血浆肌钙蛋白Ⅰ（cTnⅠ）水平与心功能分级的关系及其临床意义.方法：对428例CHF住院患者,按纽约心脏病学会（NYHA）的心功能分级,分为心功能Ⅰ级92例,Ⅱ级102例,Ⅲ级105例,Ⅳ级129例.用化学免疫荧光法测定血浆cTnⅠ,将心功能与cTnⅠ水平作相关性分析.结果：血浆cTnⅠ在不同心功能分级之间呈显著升高（P＜0.01）,心功能Ⅳ级组＞心功能Ⅲ级组＞心功能Ⅱ和Ⅰ级组,差异有显著性意义（P＜0.01）,但心功能Ⅱ级组与心功能Ⅰ级组血浆cTnⅠ水平无明显差异.心功能分级与cTnⅠ呈正相关（r值为0.7,P＜0.01）;多元回归分析显示,cTnⅠ和心衰的严重程度存在独立相关性.结论：CHF患者cTnⅠ与心衰程度相关,与病因无关.推测其可作为判定CHF严重程度的参考指标.     

血尿酸水平和肾功能变化对心衰患者的临床意义

目的：研究慢性心力衰竭（CHF）患者的肾功能和血尿酸（UA）水平与心功能分级（NYHA分级）的关系。方法：测定心功能Ⅱ级41例，Ⅲ级39例，Ⅳ级25例心衰患者及32例非心衰患者的血清尿素氮（BUN）、肌酐（Cr）、UA水平，并与左室射血分数（LVEF）等进行相关性分析。结果：心功能Ⅰ、Ⅱ、Ⅲ、Ⅳ级各组心衰患者之间的BUN、Cr、UA相比有明显差别，BUN、Cr、UA则随着心功能分级递增而递增，与LVEF呈负相关。结论：BUN、Cr、UA水平在严重心衰患者中更高，可独立预测心衰的预后。     

贫血、铁缺乏与心力衰竭严重程度之间的相关性

目的 探讨贫血、铁缺乏与心力衰竭严重程度之间的相关性.方法 入选2011年1月至12月本院收治的126例慢性心力衰竭（CHF）患者,根据美国纽约心脏病学会（NYHA）对心功能进行Ⅱ ～ Ⅳ级的分级分组,观察各组患者中贫血、铁缺乏的发生率以及血红蛋白、左室射血分数（LVEF）、心排血量（CO）、肾小球滤过率（eGFR）等指标.结果 Ⅱ、Ⅲ、Ⅳ级CHF患者,贫血发生率分别为17.50％、25.58％、55.81％,组间差异有统计学意义（P＜0.05）;铁缺乏发生率分别为27.50％、39.53％、60.47％,组间差异有统计学意义（P＜0.05）;血红蛋白水平、LVEF以及CO、eGFR指标均随着心力衰竭程度的加重而明显下降,差异均有统计学意义（P＜0.05）.结论 贫血、铁缺乏发生率随着心力衰竭程度的加重而出现明显的上升,血红蛋白浓度、肾小球滤过率、LVEF、CO与心力衰竭的严重程度有关.     

肾功能受损对血清脑钠肽水平的影响

目的 观察脑钠肽(brain natriuretic peptide,BNP)在慢性心力衰竭(chronic heart failure,CHF)不同分级时浓度的变化,以及与肾小球滤过率之间的关系.方法 各种病因导致慢性心力衰竭患者3O0例,按NYHA心功能分级标准分为心功能Ⅰ级组、心功能Ⅱ级组、心功能Ⅲ级组和心功能Ⅳ级组,并且根据肾小球滤过率估测值(estimated glom er u lar filtration rate,eGFR)分为肾功能正常组和肾功能受损组,采用酶免疫法 (ELISA)测定各组BNP浓度.结果 CHF患者血浆BNP浓度随心功能级别变化,BNP水平增高,组间差异均显著( P＜O.01);并且在同一心功能分级中,脑钠肽浓度随肾功能受损也出现了加重情况. 结论 血浆BNP水平是判断是否发生心力衰竭及其严重程度的可靠指标,当慢性心功能不全合并有肾功能受损时,体内的BNP水平会随着肾脏清除率的下降而升高.     

尿酸与心力衰竭患者心功能关系探讨

目的探讨尿酸与心力衰竭患者心功能分级的关系。方法通过对117例心力衰竭患者人院时检测血尿酸水平，根据患者心功能分级将其分为4组，并进行比较。结果心功能Ⅰ级与Ⅱ级差异无显著性（P〉0．05），Ⅱ级与Ⅲ级组、Ⅲ级与Ⅳ级组比较差异有显著性（P〈0．05）。结论随着心力衰竭的程度加重，尿酸水平也逐渐增高。     

血清同型半胱氨酸水平在扩张型心肌病心力衰竭中的临床意义

目的：探讨血清同型半胱氨酸（HCY）水平在扩张型心肌病心力衰竭（心衰）患者中的临床意义.方法：选取2008年1月至2012年5月诊断为扩张型心肌病（DCM）心衰患者86例,按照NYHA心功能分级分为DCM Ⅰ～Ⅱ级组46例和DCMⅢ～Ⅳ级组40例,观察血清HCY水平与DCM患者心功能分级、左房内径、左室舒张末期内径、左室射血分数、B型利钠肽（BNP）、心源性死亡情况.结果：DCMⅠ～Ⅱ级组治疗前HCY和左房内径、左室舒张末内径及左室射血分数与DCMⅢ～Ⅳ级组比较,差异均有统计学意义（P＜0.01）,HCY水平变化同反应心功能的各超声心动图参数指标变化趋势相一致.治疗后两组血清HCY和血BNP水平同本组治疗前比较差异均有统计学意义（P＜0.01）;两组治疗后血清HCY和血BNP水平比较差异均有统计学意义（P＜0.01）.两组随访时间及相应的血清HCY检测结果比较差异均有统计学意义（P＜0.01）.结论：血清HCY可作为DCM心衰严重程度的有效评价指标.     

慢性心力衰竭患者血清IL-1β、TNF-α水平及临床意义

目的 探讨慢性心力衰竭患者血清白细胞介素-1β（IL-1β）、肿瘤坏死因子-α（TNF-α）含量及其临床意义。方法慢性心衰组包括62例慢性心力衰竭患者，按心功能分级（NYHA）分为3组：Ⅱ级组20人，Ⅲ级组20人，Ⅳ级组22人，另设15例健康人作对照。血清TNF-α、IL-1β含量测定采用酶联免疫吸附法（ELISA）。结果 慢性心力衰竭患者血清IL-1β、TNF-α显著高于健康对照组，慢性心力衰竭患者心功能分级组间血清IL-1β、TNF-α水平差异有统计学意义，心功能Ⅳ级组显著高于心功能Ⅱ级组、Ⅲ级组。结论 慢性心力衰竭患者血清IL-1β、TNF-α水平的变化参与慢性心力衰竭致病机制，它们之间可能还有相互作用及影响，共同参与慢性心力衰竭的发病机制。     

不同胱抑素方程对我国慢性肾脏病患者的适用性评估

目的评价在血清胱抑素C(Cys-C)含量基础上开发的肾小球滤过率(GFR)评估方程在我国慢性肾脏病(CKD)患者的适用性。方法选择2008年1月至2009年11月我院肾内科就诊的412例CKD患者,将简化MDRD方程、Cys-C方程1～5计算的GFR值与99mTc-DCPA测定的GFR(sGFR)进行比较。结果各方程计算的GFR与sGFR总体上均呈显著性相关(P<0.001),Cys-C方程4和Cys-C方程5估算的GFR与sGFR的一致性最佳,Cys-C方程4、5的准确性和精确度均高于其他方程。在CKD1～5期,Cys-C方程4、5的准确性高于其它方程(P<0.001)。所有方程中仅Cys-C方程5的偏差一致性限度在事先规定的专业界值60ml·min-1·1.73m-2之内。结论Cys-C方程4、5的准确性、精确度均优于以往的GFR评估方程,并在不同CKD分期病人中有较好的适用性。但该方程的一致性限度仍存在不足,有必要进行进一步的检验和方程,为临床提供更加准确和适用的肾功能评估方法。     

Assessing kidney function in Asia

An equation for accurate estimation of the glomerular filtration rate (GFR) is vital for staging and directing the treatment of chronic kidney disease (CKD), which is a source of considerable morbidity and mortality around the world. The Modification of Diet for Renal Disease (MDRD) equation, which includes a racial coefficient, is commonly used. The MDRD equation has been validated in Caucasian populations, but modifying the racial coefficient for Asian countries has resulted in substantially different values that may not be due to race alone. Moreover, it is sometimes difficult to define race, particularly in multi-ethnic populations and among offspring of inter-ethnic marriages. Furthermore, the precision of the MDRD equation is poorer at the early stages of CKD. New markers, such as cystatin C, and new equations may be needed to accurately assess wider ranges of GFR in multi-ethnic countries. We review the development of GFR-estimating equations from an Asian perspective.     

Impact of creatinine production on the agreement between glomerular filtration rate estimates using cystatin C-derived,and 4- and 6-variable Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations

Abstract

Background. It has recently been reported that patient selection has a strong impact on the agreement between glomerular filtration rate (GFR) estimates from serum cystatin C and creatinine. The aim of our study was to evaluate the effect of creatinine production rate (CPR) on this subject. Material and methods. GFR was estimated from serum cystatin C and from creatinine using the 4- and 6-variable Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in 50 healthy subjects, 43 patients with renal failure, 794 kidney and 104 liver transplant recipients, 61 patients with heart failure, 59 patients with biliary obstruction, and 113 critically ill patients.

Results. In the 295 patients with impaired CPR (< 900 mg/24 h/1.73 m²), discordances of more than 40% between GFR_MDRD4 and GFR_cystatinC were observed in 38% of cases, between GFR_MDRD6 and GFR_cystatinC in 22%, and between GFR_CKD-EPI and GFR_cystatinC in 27% (in all cases due to GFR overestimation from creatinine). In the 929 patients with maintained CPR (> 900 mg/24 h/1.73 m²), greater discordances than 40% between GFR_MDRD4 and GFR_cystatinC were observed in 8% of cases, between GFR_MDRD6 and GFR_cystatinC in 9%, and between GFR_CKD-EPI and GFR_cystatinC in 7% (in the major part of cases due to GFR overestimation from cystatin C). Conclusion. The main source of differences of more than 40% between GFR estimates from serum creatinine and cystatin C is a GFR overestimation in patients with low CPR and GFR underestimation in patients with high CPR by the creatinine-derived equations.     

Relative performance of two equations for estimation of glomerular filtration rate in a Chinese population having chronic kidney disease

Background  The new Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was developed to address the systematic underestimation of glomerular filtration rate (GFR) by the Modification of Diet in Renal Disease (MDRD) Study equation in patients with relatively well-preserved kidney function. Performance of the new equation in the Chinese population is unknown. The goal of the present study was to compare performance of these two equations in Chinese patients with chronic kidney disease (CKD).

Methods  We enrolled 450 Chinese patients (239 women and 211 men) with CKD in the present study. The renal dynamic imaging method was used to measure the referenced standard GFR (rGFR) for comparison with estimations using the two equations. Their overall performance was assessed with the Bland-Altman method and receiver-operating characteristics (ROC) analysis. Performance of the two equations in lower and higher estimated GFR (eGFR) subgroups was further investigated.

Results  Both eGFRs correlated well with rGFR (r=0.88, 0.81, P <0.05). In overall performance, the CKD-EPI equation showed less bias, higher precision and improved accuracy, and was better for detecting CKD. In the higher-eGFR subgroup, the CKD-EPI equation corrected the underestimation of GFR by the abbreviated MDRD equation.

Conclusions  The CKD-EPI equation outperformed the abbreviated MDRD equation not only in overall performance but also in the subgroups studied. For the present, the CKD-EPI equation appears to be the first-choice prediction equation for estimating GFR.

     

肾小球滤过测算公式在慢性肾脏病中的应用评估

目的以肾小球滤过率(GFR)为标准,评价Jelliffe公式、Cockcroft-Gault公式、简化MDRD(modified diet inrenal disease study)公式以及吴锡信公式在评估肾功能损伤中的价值。方法选择180例做GFR测定的非透析患者,以Jelliffe公式、简化MDRD公式及吴锡信公式推算GFR,以Cockcroft-Gault公式推算肌酐清除率,通过方差分析比较各推算值与GFR的差异及相关关系。结果Cockcroft-Gault公式及吴锡信公式推算值均与肾小球滤过率值有显著性差异(P=0.00)。Jelliffe公式、简化MDRD公式推算值仅在GFR<60 ml.min-1.(1.73 m2)-1时与肾小球滤过率无显著性差异,但与GFR相关性不好。结论Cockcroft-Gault公式及吴锡信公式不适用于评价中国人肾功能受损的情况。Jelliffe公式、简化MDRD公式仅在GFR<60 ml.min-1.(1.73 m2)-1时可用于粗略评价中国人肾小球滤过功能受损情况。     

Impact of creatinine production on the agreement between glomerular filtration rate estimates using cystatin C-derived,and 4- and 6-variable Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations

Background.

It has recently been reported that patient selection has a strong impact on the agreement between glomerular filtration rate (GFR) estimates from serum cystatin C and creatinine. The aim of our study was to evaluate the effect of creatinine production rate (CPR) on this subject.

Material and methods.

GFR was estimated from serum cystatin C and from creatinine using the 4- and 6-variable Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in 50 healthy subjects, 43 patients with renal failure, 794 kidney and 104 liver transplant recipients, 61 patients with heart failure, 59 patients with biliary obstruction, and 113 critically ill patients.

Results.

In the 295 patients with impaired CPR (< 900 mg/24 h/1.73 m²), discordances of more than 40% between GFR_MDRD4 and GFR_cystatinC were observed in 38% of cases, between GFR_MDRD6 and GFR_cystatinC in 22%, and between GFR_CKD-EPI and GFR_cystatinC in 27% (in all cases due to GFR overestimation from creatinine). In the 929 patients with maintained CPR (> 900 mg/24 h/1.73 m²), greater discordances than 40% between GFR_MDRD4 and GFR_cystatinC were observed in 8% of cases, between GFR_MDRD6 and GFR_cystatinC in 9%, and between GFR_CKD-EPI and GFR_cystatinC in 7% (in the major part of cases due to GFR overestimation from cystatin C).

Conclusion.

The main source of differences of more than 40% between GFR estimates from serum creatinine and cystatin C is a GFR overestimation in patients with low CPR and GFR underestimation in patients with high CPR by the creatinine-derived equations.     

Association between serum uric acid and different states of glucose metabolism and glomerular filtration rate

Background Recently, it has been suggested that the serum uric acid （SUA） level decreased in diabetic patients. The aim of this study was to explore the association between SUA level and different state of glucose metabolism and glomerular filtration rate （GFR） reflected by the simplified Modification of Diet in Renal Disease （MDRD） equation and to test the hypothesis that high MDRD is one of the determinants of SUA level.Methods This cross-sectional study included 2373 subjects in Beijing who underwent a 75 g oral glucose tolerance test （OGTT） for screening of diabetes. According to the states of glucose metabolism, they were divided into normal glucose tolerance, impaired glucose regulation and diabetes.Results Multiple stepwise linear regression analysis showed that adjusted by gender, SUA was positively correlated with body mass index （BMI）, waist/hippo ratio, systolic blood pressure （SBP） and triglyceride, meanwhile negatively correlated with age, hemoglobin A1c, fasting insulin and MDRD. There was an increasing trend in SUA concentration and a decreasing trend in MDRD when the levels of fasting plasma glucose （FPG） increased from low to high up to the FPG level of 8.0 mmol/L; thereafter, the SUA concentration started to decrease with further increases in FPG levels, and the MDRD started to increase with further increases in FPG levels.Conclusion This study confirmed the previous finding that SUA decreased in diabetes and provided the supporting evidence that the increased MDRD might contribute to the fall of SUA.     

How Robust are our Methods of Detecting Impaired Glomerular Filtration Rate in the Intensive Care Unit?

Background

Serum creatinine is not a sensitive marker to assess early loss of renal function in acute kidney injury. Timed creatinine clearance and several formula used to predict glomreular filtration rate have not been validated.

Methods

In a prospective observational study in 50 adult patients admitted to the intensive care unit with apparent normal renal function, we assessed the glomerular filtration rate by the formula methods and timed creatinine clearance.

Result

The mean serum creatinine was 0.77mg/dl, SD ± 0.15 (range 0.5-1.14 mg/dl). The mean measured creatinine clearance was 87.15 ml/min/1.73m², SD ± 20.5 (range 56.9-137 ml/min/1.73m²). In 25 (50%) patients, one hour urinary creatinine clearance was <80 ml/min/1.73m² and in two (4%) patients, the creatinine clearance was <60 ml/min/1.73m². Spearman correlation coefficient and regression analysis revealed a statistically significant correlation for the Cockcroft-Gault and predictive equations when compared with measured creatinine clearance. The differences between the predictive equations and creatinine clearance, as illustrated by the ±95% confidence interval in the Bland-Altman graphs was very significant [Cockcroft- Gault = −40.3 to 17.7 ml/min/ 1.73m², Modification of Diet in Renal Disease equation = −46.2 to 30.6 ml/min/1.73m² and the simplified Modification of Diet in Renal Disease equation = −72.8 to 24.8 ml/min/1.73m²].

Conclusion

Formula methods and creatinine clearance are more sensitive than serum creatinine in detecting early phase of acute kidney injury. However, there is no agreement between these methods of glomerular filtration rate estimation.Key Words: Acute kidney failure, Glomerular filtration rate     

肾小球滤过率评价糖尿病患者肾功能的意义及方法学比较

目的 评价Cockcroft-Gault公式及简化肾脏病膳食改良试验（MDRD）公式计算的肾小球滤过率对于糖尿病患者肾功能估计的适用性。方法测定189例2型糖尿病患者血肌酐浓度,对两种公式计算的肾小球滤过率分别与^99Tc^m-DTPA（^99Tc^m标记的二乙三胺五乙酸）肾动态显像测定的肾小球滤过率（金标准）进行比较,以便评价筛选出更为适用于糖尿病患者肾功能估计的公式。结果两种公式对于GFR的计算均偏离于实际值,Cockcroft-Gault公式过低估计了实际值,而简化MDRD公式过高估计了实际值。相关分析、一致性检验及受试者工作特性曲线分析表明,简化MDRD公式与金标准的相关系数、一致率及准确性均高于Cockcroft-Gault公式。结论对于糖尿病患者肾功能的估计,简化MDRD公式优于Cockcroft-Gauh公式。