The Implication of Dropping Race from the MDRD Equation to Estimate GFR in an African American-Only Cohort

The widely used Modification of Diet in Renal Disease (MDRD) formula adapts a 1.212 multiplier for individuals who are identified as African Americans (AAs) or Blacks, which leads to a higher GFR estimation. As it stands, AAs have a lower prevalence of chronic kidney disease (CKD) but higher incidence of end-stage renal disease (ESRD) compared with Whites. Many hypotheses have been postulated to explain this paradox, but the imprecision of the GFR estimation with race-adaptation could be contributory. We performed a single-center, longitudinal, retrospective study on a cohort of outpatient AA patients using the MDRD and MDRDrace removed and CKD-EPI and CKD-EPIrace removed and their progression to CKD G5 (eGFR <15 ml/min/1.73 m2). 327 patients were analyzed. Median follow-up was 88.1 months (interquartile range, 34.4–129.1). When race was removed from MDRD, 39.9% of patients in CKD G1/2 were reclassified to CKD G3a, 72.6% of patients in CKD G3a would be reclassified to CKD G3b, and 54.1% and 36.4% of patients would be reclassified from CKD 3b to CKD G4 and CKD G4 to CKD G5, respectively p < 0.0001 . Comparing the CKD-EPI formula against the MDRD in our cohort, we found that 8.2%, 18.8%, and 11.4% of patients were reclassified from CKD G1/2 to CKD G3a, CKD G3a to G3b, and CKD G3b to CKD G4 respectively. Overall median time to progression to CKD G5 was 137.4 (131.9–142.8) months in patients who were not reclassified and 133.6 (127.6–139.6) months for patients who were reclassified by MDRDrace removed p < 0.288 . Concerns of inequitable access to healthcare have elicited calls to review race-corrected eGFR equations. A substantial number of individuals would have their CKD stage reclassified should have the MDRDrace removed equation be adopted en masse on an AA-only population. The discrepancy is highest at the 45–59 and >60 ml/min/1.72 min2 ranges. This will have tremendous impact on our center’s approach to pharmacological dosing, referral system, best practices, and outcome surveillance. Comprehensive review of the current “race-corrected” eGFR will require a multifaceted approach and adjunctive use of noncreatinine-based approach.

CORRELATION OF THYROID HORMONES IN PATIENTS WITH CHRONIC KIDNEY DISEASE: AN OBSERVATIONAL STUDY

Introduction: Chronic kidney disease (CKD) is an international public health problem affecting about 5–10% of the population. It is the ninth leading cause of death. A trend towards increased incidence and prevalence is being reported worldwide with epidemic proportions in many countries. CKD is associated with variety of endocrine disturbances among which thyroid dysfunction is most common. This is probably due to reduce circulating hormone levels, altered binding of hormone to carrier protein or due to reduced peripheral metabolism of hormone. Materials and Methods: The study included 100 patients diagnosed with CKD. Both male and female patients aged between 30-70 years were selected for the study. Estimated Glomerular Filtration Rate (eGFR) was calculated using Modification of Diet in Renal Disease (MDRD) formula. Total T3, Total T4, TSH levels were measured by CLIA methodology. Results: Statistically significant alteration in TSH (p<0.01) values were seen with eGFR suggesting that alteration in the eGFR may lead to thyroid hormone resistance. Keywords: Chronic Kidney Disease(CKD), Estimated Glomerular Filtration Rate (eGFR), Modification of Diet in Renal Disease (MDRD)

The predictive value of creatinine clearance for mortality in patients undergoing revascularization

Background Renal function plays a significant role in the prognosis and management of patients with multi-vessel coronary artery disease (CAD) referred for revascularization. Current data lack precise risk stratification using estimated glomerular filtration rate (eGFR) and creatinine clearance. Methods This prospective study includes a three-year follow-up of 1112 consecutive patients with multi-vessel CAD enrolled in the 22 hospitals in Israel that perform coronary angiography. Results The Mayo formula yielded the highest mean eGFR (90 ± 26 mL/min per 1.73m2) and chronic kidney disease-epidemiology collaboration (CKD-EPI) the lowest (76 ± 24 mL/min per 1.73m2). Consequently, the Mayo formula classified more patients (56%) as having normal renal function. There was a significant and strong correlation between the values obtained from all five formulas using Cockcroft-Gault as the reference formula: Mayo: r = 0.80, p < 0.001; CKD-EPI: r = 0.87, p < 0.001; modification of diet in renal disease (MDRD): r = 0.84, p < 0.001; inulin clearance-based: r = 0.99, p < 0.001). Multivariable analysis demonstrated that decreased renal function is an independent predictor of 3-year mortality in all five formulas, with risk increasing by 15–25% for each 10-unit decrease in eGFR. Despite the similarities between the formulas, the ability to predict mortality was highest in the Mayo formula and lowest in MDRD. Conclusions Our data suggest that while the Mayo formula is not currently recommended by any nephrology guidelines, it may be an alternative formula to predict mortality among patients with multivessel CAD, including to the widely used MDRD formula.

PREVALENCE OF NEPHROPATHY AND ITS PARAMETERS IN PATIENTS WITH DIABETES MELLITUS- A PROSPECTIVE STUDY IN A CENTRAL INDIAN POPULATION

Background: Hyperglycemia is an important risk factor for the development of diabetic nephropathy. In the initial stages ie micro albuminuria the DKD is clinically detectable and can even be reversed. Hence early screening of diabetic patients is important. Hence the aim of this study was to evaluate the prevalence of nephropathy in a cross section of diabetic patients. Objectives: The Aim of our study was to evaluate the prevalence of nephropathy in recently detected diabetic patients by evaluating microalbuminuria, serum creatinine and creatinine clearance. Methods: A total of 120 patients above 18 years were included in the study and were divided into three groups according to age and were further divided into three groups as per the duration of diseases Patients were again divided into two groups according to the gender. The GFR was calculated as per the MDRD formula and the patients were divided further as per the stage of CKD. Serum Creatinine levels were calculated and the variables associated with CKD were adjusted by Logistic Regression. Results: Our results suggests that 41.25% of subjects were in mild to severe nephropathy out of which 16.25 % were within the three years of diagnosis, thus suggesting the role of early and routine investigation in diabetic patients. Conclusion: Hence the role of life style is clearly emphasized by our results. Although when the variables were adjusted with the logistic regression the occupation was not that significant. Keywords: Albuminuria, Diabetes mellitus (DM), Diabetic Kidney Disease (DKD), Diabetic nephropathy (DN), Serum Creatinine.

PREVALENCE OF NEPHROPATHY AND ITS PARAMETERS IN PATIENTS WITH DIABETES MELLITUS- A PROSPECTIVE STUDY IN A CENTRAL INDIAN POPULATION

Background: Hyperglycemia is an important risk factor for the development of diabetic nephropathy. In the initial stages ie micro albuminuria the DKD is clinically detectable and can even be reversed. Hence early screening of diabetic patients is important. Hence the aim of this study was to evaluate the prevalence of nephropathy in a cross section of diabetic patients. Objectives: The Aim of our study was to evaluate the prevalence of nephropathy in recently detected diabetic patients by evaluating microalbuminuria, serum creatinine and creatinine clearance. Methods: A total of 120 patients above 18 years were included in the study and were divided into three groups according to age and were further divided into three groups as per the duration of diseases Patients were again divided into two groups according to the gender. The GFR was calculated as per the MDRD formula and the patients were divided further as per the stage of CKD. Serum Creatinine levels were calculated and the variables associated with CKD were adjusted by Logistic Regression. Results: Our results suggests that 41.25% of subjects were in mild to severe nephropathy out of which 16.25 % were within the three years of diagnosis, thus suggesting the role of early and routine investigation in diabetic patients. Conclusion: Hence the role of life style is clearly emphasized by our results. Although when the variables were adjusted with the logistic regression the occupation was not that significant. Keywords: Albuminuria, Diabetes mellitus (DM), Diabetic Kidney Disease (DKD), Diabetic nephropathy (DN), Serum Creatinine.

Jämförelse av CKD-EPI och MDRD ekvationsformler för estimerad glomerulär filtrationshastighet.

Introduction: In the profession as radiology nurse contrast media is used daily in radiologic examinations. In order to determine the volume of contrast media that patients should be administered and to prevent contrast-induced nephropathy equation formulas are applied to calculate the kidney function glomerular filtration rate. Two formulas were compared the CKD-EPI and MDRD. The aim was to compare which of the two most commonly used equation formulas is the most optimal for calculating estimated GFR. Methods: This study was conducted as a literature study, where 11 articles were quality assessed and compiled. Results: The CKD-EPI formula generally showed better performance for estimating GFR in accuracy, precision and bias than the MDRD formula. However, both equation formulas present inadequacies and are not universal as they are not applicable to all individuals. Conclusions: At the moment the CKD-EPI formula appears to be the most applicable, although more research is required in order to develop equation formulas which cater to all types of patients.

Comparison of Jaffe and enzymatic methods for creatinine estimation and their effect in GFR calculation in a tertiary care hospital

Introduction and Aim: Serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) gives the idea of overall functional status of kidney. Measurement of SCr by different method and discordant result between them can misclassify different stages of chronic kidney disease (CKD). Many of the tertiary care health centre, SCr measured by Jaffe method is still the method of choice because of its cost effectiveness even if it is more susceptible for interference. Our aim was to measure SCr level by both Jaffe’s & enzymatic method and analysing the discordance rate of eGFR and their effect in staging of kidney disease in CKD patients. Materials and Methods: In this observational study 330 serum sample were analysed for creatinine by Jaffe’s and enzymatic methods in a fully automated analyser using commercially available kits. Modification of Diet in Renal Disease (MDRD) formula was used for estimating GFR. Results: In 330 subjects eGFR values calculated on incorporating SCr were found as 58.84 ± 68.34 (median (IQR) = 26.67(15.09-90.84) and 44.49 ± 41.18 (Median (IQR) = 26.86 (14.69-67.69)) ml/min/1.73 m2 respectively by Jaffe’s and enzymatic method. Concordance correlation coefficient between two methods for SCr was statistically significant. Bland-Altman plot showed with increasing value of SCr, the difference between the SCr values given by these two methods increased. Jaffe’s creatinine has lower value in comparison to enzymatic Cr. There was a significant difference between eGFR obtained from SCr estimated by Jaffe’s and enzymatic method. Conclusion: All laboratory should use uniform method for creatinine estimation. Enzymatic method for creatinine estimation should not be compromised over cost of test, so that less variability in creatinine result can lead to more accurate staging of the disease.

A novel nomogram to predict the reliability of estimated glomerular filtration rate formula in oncology patients

Background: Formulae of estimated glomerular filtration rate (eGFR) based on serum creatinine (Scr) are routinely used in oncology patients, however, they are inaccurate in some populations. Our aim was to assess the agreement of eGFR formulae and thereby build a nomogram to predict the reliability of estimates. Methods: Measured GFR (mGFR) using isotope from 445 oncology patients were compared with eGFR from six formulae (Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD), modified MDRD formulae for Chinese (C-MDRD), Chronic Kidney Disease Epidemiology (CKD-EPI) Collaboration, Wright and full age spectrum (FAS)). Bias, precision and accuracy of eGFR formulae were examined. We also evaluated statistics of agreement: the total deviation index (TDI), the concordance correlation coefficient (CCC) and the coverage probability (CP). Multivariate logistic regression was applied to identify characteristics associated with inaccurate eGFR and construct a predictive nomogram. Results: All eGFR formulae tended to overestimate the eGFR. The percentage of patients with eGFR within 30% the mGFR ranged from 38.0% to 62.8%. Cockcroft-Gault and MDRD showed low bias and high precision. The MDRD formula exhibited lowest TDI, meaning that 90% of estimations ranged from -36 to 36% of mGFR. Multivariate logistic regression showed that inaccuracy of MDRD was found in elderly patients or in patients with eGFR greater than 120 ml/min. A nomogram was constructed to help oncologists to predict the risk of inaccuracy of eGFR. The calibration curve showed good agreement. Conclusions: Our results suggest that the error of eGFR by any formulae was common and wide in Chinese oncology patients. Our nomogram may assist oncologists in decision-making when mGFR is needed.

Comparison of commonly used creatinine-based GFR estimating formulas in elderly female non-diabetic patients with chronic kidney disease

Introduction: Measuring glomerular filtration rate (GFR) with the isotopic method is a gold standard. However, it is an elaborate and expensive procedure, so in everyday practice GFR is estimated with creatinine-based formulas. Despite the number of studies, it remains unclear which GFR estimating equation is the most accurate, especially in increasing elderly population. Aim: The aim of this study was to compare the commonly used formulas to assess which one of them should be used in elderly female non-diabetic patients suffering from chronic kidney disease (CKD) Material and methods: 336 non-diabetic females aged 70 and more were qualified to the study. On the basis of serum creatinine concentration, estimated GFR (eGFR) was estimated using various formulas. Results and discussion: The eGFR and CKD stages differ significantly depending on the used formula. The modification of diet in renal disease equation (MDRD) formula showed slightly, but still significantly, better correlation with creatinine concentration in serum than the CKD epidemiology collaboration equation. The Cockcroft-Gault equation formula was significantly inferior to above mentioned equations. The receiver operating characteristic curves showed that MDRD is the most sensitive equation and the differences between formulas compared in pairs were significant. Conclusions: Due to its highest correlation with creatinine and its highest sensitivity and specificity, the MDRD formula seems to be the most accurate equation to estimate GFR in elderly non-diabetic females.

Comparison of long-term kidney functions after radical nephrectomy and simple nephrectomy

Objective To determine if there is a difference in proceeding to CKD between patients who had undergone radical nephrectomy (RN) and simple nephrectomy (SN) for different indications by comparing the short- and long-term renal function. Materials and Methods We retrospectively analyzed the records of all patients who underwent nephrectomy (either for malign or benign indications) in our clinic between January 2007 and September 2017. The patients were divided into 2 groups according the type of surgery: 1) Radical nephrectomy Group, 2) Simple Nephrectomy Group. Renal function was evaluated with Glomerular Filtration Rate (GFR) calculated using the MDRD formula. Results A total of 276 patients were included in the study. There were 202 patients in RN Group and 74 patients in SN Group. The mean age of the patients in RN Group and SN Group were age 59,2 ± 11,5 and 49,9 ± 15,1 years, respectively (p = 0.001). GFR levels of patients in RN Group versus SN Group were as follows: Preoperative period: 84.9 vs. 81 mL/min/1.73 m2; postoperative 1st day: 60.5 vs. 84.4 mL/min/1.73 m2, postoperative 1st month 58.9 vs. 76 mL/min/1.73 m2, postoperative 1st year: 59.5 vs. 74.1 mL/min/1.73 m2; at last control 60.3 and 76.1 mL/min/1.73 m2. While preoperative GFR was found to be similar in two groups (p = 0.26), postoperative GFR values were found to be significantly lower in Group RN (p < 0.001). In comparison of the decrease in GFR in two groups at last follow-up, significantly higher decrease was observed in RN Group, 29% vs. 6%, (p < 0.05). Conclusion The decrease in GFR exists more common and intensive after RN compared to SN. In long-term, compensation mechanisms that develop after sudden nephron loss like radical nephrectomy deteriorates kidney function more than gradual nephron loss as in benign etiologies which indicates simple nephrectomy.