Chronic Kidney Disease

Aggressive blood pressure reduction and renin–angiotensin system blockade in chronic kidney disease: time for re-evaluation?

Should Estimated Glomerular Filtration Rate Be Adjusted for Race?

To determine the concordance between the Modification of Diet in Renal Disease (MDRD) and Cockcroft-Gault equations for glomerular filtration rate (GFR) estimation, the impact of using each equation on antimicrobial dosing, the difference in estimated GFR in patients with acute kidney disease (AKD) versus chronic kidney disease (CKD), and the correlation between the MDRD, Cockcroft-Gault equation, and expert medical opinion for estimating GFR in patients with AKD. Retrospective cohort study. A 689-bed academic medical center. A total of 372 adults hospitalized with either AKD or CKD between January 1, 2007, and May 31, 2007, and who received at least one antimicrobial drug; patients with stage 1 or 2 CKD or those receiving dialysis were excluded. Data were collected from electronic medical records on patient characteristics, laboratory values, antimicrobial drugs requiring dosage adjustment due to renal dysfunction, and estimated GFRs provided by the laboratory (MDRD estimation). In addition, estimated GFRs were calculated using the Cockcroft-Gault equation. For patients with AKD, a third GFR was estimated by a nephrologist. For all patients, the MDRD GFR was significantly higher than the Cockcroft-Gault GFR (p<0.001). Level of concordance for the need for dosage adjustment based on the two equations was moderate (kappa coefficient 0.57, 95% confidence interval 0.5-0.63); 99.1% of patients with discordant dose recommendations would receive a higher dose if the MDRD GFR was used. In the AKD versus CKD groups, mean MDRD GFR was significantly higher than the Cockcroft-Gault GFR in both groups (p<0.0001), but the difference was significantly greater in the CKD group (p<0.0001). In patients with AKD, the GFR estimated by expert opinion was greater than that estimated by the Cockcroft-Gault equation (p=0.04), but was similar to the MDRD equation (p=0.07). The estimated GFR obtained with the MDRD equation was consistently higher than that from the Cockcroft-Gault equation in patients with AKD or CKD. In patients with AKD, the MDRD GFR more closely correlated with expert opinion than the Cockcroft-Gault, suggesting that the MDRD method may be applicable to this patient population. Moderate concordance between the two equations for the need for antimicrobial dosage adjustment due to renal dysfunction was found, but the specific dosage change was different for approximately 40% of patients, with 99% receiving higher doses when the MDRD GFR is used. These dosing differences may be significant, depending on drug safety profile, type of infection, and causative pathogen.

Background: The glomerular filtration rate (GFR) is considered the gold standard for assessing renal function. According to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines, GFR estimation is often carried out using predictive equations that incorporate serum creatinine levels, along with demographic factors such as age, gender, race, and body size. However, these equations exhibit varying levels of accuracy across different populations, necessitating the evaluation of their performance and clinical relevance in diverse patient groups.Objectives: This study aimed to evaluate the performance of three commonly used GFR estimation equations, the Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, along with their race-modified versions, by comparing them with measured 24-hour creatinine clearance (CrCl) in adult patients with chronic kidney disease (CKD).Methods: A cross-sectional descriptive study was conducted at Jos University Teaching Hospital (JUTH) between November 2019 and July 2020, involving 111 consecutively recruited CKD patients. Data collection included medical history, physical examination, laboratory investigations, calculation of CrCl, estimated glomerular filtration rate (eGFR) using different equations, and albumin-creatinine ratio (ACR). Statistical analysis was performed using SPSS version 20 (IBM Inc., Armonk, New York), with p-values <0.05 considered statistically significant.Results: The mean age of participants was 51.1±15.5 years. Diabetes mellitus was the most common cause of CKD, affecting 38% of the cohort. Among participants, 31% and 22% were classified as having stage 5 and stage 4 CKD, respectively. The median CrCl was 26 (9-56) mL/min. The median eGFR values across the equations were as follows: CG, 26 (11-60) mL/min/1.73m²; MDRD, 26 (11-60) mL/min/1.73m²; MDRD1, 22 (9-50) mL/min/1.73m²; CKD-EPI, 26 (10-62) mL/min/1.73m²; and CKD-EPI1, 22 (9-53) mL/min/1.73m². Strong positive correlations were observed between measured CrCl and the estimated GFR from each equation: CG (r=0.948, p=0.001), MDRD (r=0.940, p=0.001), MDRD1 (r=0.939, p=0.001), CKD-EPI (r=0.943, p=0.001), and CKD-EPI1 (r=0.942, p=0.001). Furthermore, significant correlations were found between the different GFR equations themselves, with the highest correlation observed between MDRD and CKD-EPI (r=0.999, p=0.001). The median ACR was 395.5 (45.3-2887.0) mg/g, and albuminuria was present in 82% of participants. All three GFR equations closely approximated the measured CrCl of 26 mL/min/1.73m². The equations performed optimally in patients with GFR values below 45 mL/min, with the CG equation exhibiting the least bias and the highest precision. Regression analysis revealed a significant association between albuminuria and all GFR equations and a notable association between age and CrCl, CG, and CKD-EPI estimates.Conclusion: The CG, MDRD, and CKD-EPI equations demonstrated comparable accuracy to measured 24-hour CrCl in estimating GFR in Nigerian patients with CKD. These findings support the clinical use of these predictive equations for renal function assessment in CKD, though local validation in diverse populations is recommended for optimal clinical application.

There was a good correlation between Glomerular Filtration Rate (GFR) values estimated by any of the 3 methods. Crcl correlated better with Cockcroft-Gault (CG eGFR) than Modification of Diet in Renal Disease (MDRD eGFR) and there was also a very good correlation between CG eGFR and MDRD eGFR. Based on this result we feel that in advanced CKD all 3 methods give similar GFR estimates but in earlier stages of Chronic Kidney Disease (CKD) Creatinine clearance (Crcl) gives higher estimate of GFR. Thus use of Crcl may wrongly classify patients into less severe stages of CKD which might lead to delay in initiation of proper treatment. MATERIALS AND METHODS: CKD patients were selected on the basis of serum creatinine levels. S.C > 2.5 mg/dl values were considered to be having CKD. 75 Samples were tested. Both males & females patients are taken in this study. Serum Creatinine & Urinary Creatinine by Jaffe's method, Blood Urea by Urease method, Urinary Protein by Pyrogallol red method, estimation of GFR by three methods. Creatinine Clearance &eGFR by using Cockcroft- Gault& MDRD equations. RESULT: A total of 75 patients attending the nephrology department (P.E.S Medical College, Kuppam)for treatment and monitoring for chronic kidney disease where included in the present study. Serum creatinine, serum urea and creatinine clearance were measured in all these patients as per methods described under materials and methods. Estimated GFR (eGFR) using CG (Cock croft) and MDRD (Modification of Diet in renal disease) formulae were calculated. Majority of the cases were complications due to long standing diabetes mellitus or hypertension. CONCLUSION: Creatinine Clearance over estimates GFR in early stages of CKD. Use of Crcl to assess GFR may not be proper to classify CKD into different stages. Any of the 3 methods (Crcl, CG eGFR and MDRD eGFR) can be used as markers of GFR in advanced stages of CKD. MDRD eGFR is a better indicator of eGFR for staging CKD in early stages of CKD. All patients included in the present study had gross proteinuria even in early stages of CKD. There was no correlation between protein: creatinine ratio and CKD stages. We recommend a larger study reporting eGFR using MDRD equation along with serum creatinine for evaluation of renal function and confirm our findings. Estimated Glomerular Filtration Rate (eGFR), Glomerular Filtration Rate (GFR), Cockcroft-Gault (CG eGFR), Modification of Diet in Renal Disease (MDRD eGFR), Creatinine clearance (Crcl), Chronic Kidney Disease (CKD).

Drug therapy in kidney disease

Comparison of CKD Awareness in a Screening Population Using the Modification of Diet in Renal Disease (MDRD) Study and CKD Epidemiology Collaboration (CKD-EPI) Equations

Nutrition and chronic kidney disease

Prediction equations of glomerular filtration rate (GFR) may facilitate early detection, evaluation and management of chronic kidney disease (CKD). However, the reliability of these equations was not extensively studied in our CKD population. Hence, the present study was aimed to determine the performance of modification of diet in renal disease (MDRD) and Cock-croft Gault formulas in predicting GFR in CKD patients and their relationship with the measured GFR. A total of 104 subjects (71 male and 33 female, aged 26-68 years) with different stages of CKD were recruited for this study; we excluded 51 patients due to improper collection of 24-h urine. The GFR was measured using 24-h creatinine clearance and predicted by the Cockcroft Gault, the 4-variable MDRD and the 6-variable MDRD equations. Prediction equations correlated well with the measured GFR. However, the predicted GFR using the 4-variable MDRD equation revealed a highly significant positive correlation with the GFR measured by creatinine clearance (r = 0.86, P < 0.001), followed by the 6-variable MDRD and Cockcroft-Gault equations with r = 0.85 and 0.77, P < 0.001, respectively. In conclusion, the present study predicts that the 4-variable MDRD is the best available equation for predicting GFR in our CKD population.

In Reply to ‘Estimated GFR for Drug Dosing: A Bedside Formula’, ‘Drug Dose Adjustments in Patients With Renal Impairment’, ‘Use of the MDRD Study Equation for Drug Dosing’, and ‘Estimated GFR vs Creatinine Clearance for Drug Dosing’

The Cockcroft-Gault (CG), the Modification of Diet in Renal Disease (MDRD) and the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) formulae are often used to estimate glomerular filtration rate (GFR). The objective was to determine the best method for estimating GFR in older adults. A cross-sectional study was conducted at the geriatric wards of two hospitals in The Netherlands. Patients aged 70 years or above with an estimated (e)GFR below 60 ml min⁻¹ 1.73 m⁻² were included. The CG, CG calculated with ideal bodyweight (IBW), MDRD and CKD-EPI formulae were compared with a criterion standard, sinistrin clearance. Renal function was classified into five stages according to the National Kidney Foundation Disease Outcomes Quality Initiative chronic kidney disease classification, as follows (in ml min⁻¹ 1.73 m)⁻²: stage 1, eGFR ≥ 90; stage 2, eGFR of 60-89; stage 3, eGFR of 30-59; stage 4, eGFR of 15-29; and stage 5, eGFR < 15. Sixteen patients, 50% male, with a mean age of 82 years (range 71-87 years) and mean body mass index 26 kg m⁻² (range 18-36 kg m⁻²), were included. On average, all formulae slightly overestimated GFR, as follows (in ml min⁻¹ 1.73 m⁻²: CG +0.05 [95% confidence interval (CI) -28 to +28]; CG with IBW +0.03 (95% CI -20 to +20); MDRD +9 (95% CI -16 to +34); and CKD-EPI +5 (95% CI -20 to +29). They classified kidney disease correctly in 68.8% (CG), 75% (CG with IBW), 43.8% (MDRD) and 68.8% (CKD-EPI) of the participants, respectively. The CG, CG with IBW, MDRD and CKD-EPI formulae estimate the mean GFR of a population rather well. In individual cases, all formulae may misclassify kidney disease by one stage.

INTRODUCTION The disease complex comprised of atherosclerosis, chronic kidney disease (CKD) and other associated chronic vascular diseases is the leading cause of mortality worldwide. Microalbuminuria is a marker for vascular damage in the heart, kidney and brain. This paper presents selected findings of the clinical-epidemiological Isle of Youth Study (ISYS) of markers for kidney and vascular damage from chronic vascular diseases and their common risk factors in total population, focusing on Phase 2 reassessment (in 2010) of Phase 1 (2004 to 2006) results. OBJECTIVES (1) Update the prevalence of risk factors in the study population aged ≥20 years (adult population). (2) Confirm presence of microalbuminuria in at-risk adults diagnosed as presumptive positives in Phase I. (3) Evaluate association between microalbuminuria and selected risk factors. METHODS Of 3779 adults positive for microalbuminuria in ISYS Phase 1, 73.1% were reevaluated. The risk-factor questionnaire was re-administered and blood pressure, weight and height were measured. Blood was tested for creatinine, glycemia, cholesterol and triglycerides. Glomerular filtration rate was calculated using the Modification of Diet in Renal Disease (MDRD) formula. Albuminuria was measured in urine using Micral-Test (Germany) and albumin/creatinine ratio (ACR) by nephelometry. This paper uses ACR as the reference for analyzing risk factor associations. Double-entry tables were developed to analyze association among microalbuminuria, risk factors and co-morbidities. RESULTS Most prevalent risks were hypertension, consumption of nonsteroidal anti-inflammatory drugs (NSAIDs), excess weight and hypertriglyceridemia. Microalbuminuria was confirmed in 18% of cases, using the same test. Elevated prevalence of microalbuminuria was positively associated with advancing age, male sex, underweight, smoking, NSAID use, dyslipidemia, hypertension, diabetes, heart disease and stroke. CONCLUSIONS The at-risk cohort studied presented low levels of confirmation for positive microalbuminuria. Positive microalbuminuria stratified individuals at greatest risk, except for obesity.

Estimating glomerular filtration rate in Asian subjects: where do we stand?

Application of GFR-estimating equations in Chinese patients with chronic kidney disease

1416 ARE WE EVALUATING PROPERLY THE RENAL FUNCTION WITH THE MODIFICATION OF DIET IN RENAL DISEASE (MDRD) IN PATIENTS WITH ORTHOTOPIC ILEAL NEOBLADDER?