Kumar B Vinodh, Mohan Thuthi
Senior Resident, Department of Biochemistry, Esic Medical College Hospital and Pgimsr, Chennai, Tamil Nadu, India.
Assistant Professor and Specialist Grade, Department of Biochemistry, Esic Medical College Hospital and Pgimsr, Chennai, Tamil Nadu, India.
J Clin Diagn Res. 2017 May;11(5):BC09-BC12. doi: 10.7860/JCDR/2017/25124.9889. Epub 2017 May 1.
The assessment of Glomerular Filtration Rate (GFR) is essential for clinical practice in assessing kidney function, drug dosing, detecting and estimating the prognosis of Chronic Kidney Disease (CKD). The most common practical method for assessing GFR is performed with a 24 hour/timed urine collection for creatinine clearance evaluation. The estimation of eGFR by creatinine based formulae is known to be a rapid and reliable means of approximation of creatinine clearance.
To compare eGFR using three commonly used Formulae {Modification of Diet in Renal Disease Study Equation (MDRD 2006), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI 2009) and Cockcroft-Gault Formula} with 24 hour creatinine clearance and to identify which amongst the 3 formulae for eGFR closely correlates with 24 hour creatinine clearance in a secondary care hospital.
We retrospectively collected laboratory data requested for 24 hour creatinine clearance in the period from January 2014 to August 2016. Totally 91 laboratory request for 24 hour creatinine clearance data were obtained. The paired-t-test was used for comparison since all parameters used in the study were numerical, all patients came from same population and all had paired results.
The eGFR by MDRD formulae had a statistically insignificant p-value (p > 0.05) i.e., good approximation in the II, III, IV and V stages of CKD on comparison with 24 hour creatinine clearance. The eGFR by CKD-EPI formulae had a statistically insignificant p-value (p > 0.05) in the II, IV and V stages of CKD. The eGFR by Cockcroft-Gault Formulae had a statistically insignificant p-value (p > 0.05) in the I, II and V stages of CKD.
The Creatinine based GFR estimation provides a more accurate assessment of 24 hour creatinine clearance and kidney function than measuring serum creatinine alone but have certain limitations in few clinical circumstances. No single equation will be optimal for all populations. But the result of this study showed MDRD 2006 formulae to be more accurate than CKD-EPI 2009 and Cockcroft-Gault formulae in estimating GFR, detection of CKD, drug dosing and estimating prognosis.
肾小球滤过率（GFR）的评估对于临床实践中评估肾功能、药物剂量、检测和评估慢性肾脏病（CKD）的预后至关重要。评估GFR最常用的实际方法是通过收集24小时/定时尿液来评估肌酐清除率。基于肌酐的公式估算eGFR是一种快速且可靠的估算肌酐清除率的方法。
比较使用三种常用公式（肾脏病膳食改良研究方程（MDRD 2006）、慢性肾脏病流行病学协作组公式（CKD-EPI 2009）和Cockcroft-Gault公式）估算的eGFR与24小时肌酐清除率，并确定在一家二级护理医院中，这三种eGFR公式中哪一种与24小时肌酐清除率密切相关。
我们回顾性收集了2014年1月至2016年8月期间要求进行24小时肌酐清除率检测的实验室数据。共获得91份24小时肌酐清除率数据的实验室申请。由于研究中使用的所有参数均为数值型，所有患者来自同一人群且所有结果均为配对结果，因此使用配对t检验进行比较。
与24小时肌酐清除率相比，MDRD公式估算的eGFR在CKD的II、III、IV和V期的p值无统计学意义（p>0.05），即近似度良好。CKD-EPI公式估算的eGFR在CKD的II、IV和V期的p值无统计学意义（p>0.05）。Cockcroft-Gault公式估算的eGFR在CKD的I、II和V期的p值无统计学意义（p>0.05）。
基于肌酐的GFR估算比单独测量血清肌酐能更准确地评估24小时肌酐清除率和肾功能，但在少数临床情况下存在一定局限性。没有一个单一的方程对所有人群都是最优的。但本研究结果表明，在估算GFR、检测CKD、药物剂量和评估预后方面，MDRD 2006公式比CKD-EPI 2009和Cockcroft-Gault公式更准确。
