Estimation of Kidney Function in Patients With Multiple Myeloma: Implications for Lenalidomide 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.

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.

We evaluated the performance of the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Cockcroft-Gault (CG) equations against creatinine clearance (CrCl) to estimate glomerular filtration rate (GFR) in 51 patients with Type 2 diabetes. The CrCl value was obtained from the average of two consecutive 24-h urine samples. Results were adjusted for body surface area using the Dubois formula. Serum creatinine was measured using the kinetic Jaffe method and was calibrated to standardized levels. Bland-Altman analysis and kappa statistic were used to examine agreement between measured and estimated GFR. Estimates of GFR from the CrCl, MDRD, CKD-EPI and CG equations were similar (overall P = 0.298), and MDRD (r = 0.58; 95% CI: 0.36-0.74), CKD-EPI (r = 0.55; 95% CI: 0.33-0.72) and CG (r = 0.61; 95% CI: 0.39-0.75) showed modest correlation with CrCl (all P < 0.001). Bias was -0.3 for MDRD, 1.7 for CKD-EPI and -5.4 for CG. All three equations showed fair-to-moderate agreement with CrCl (kappa: 0.38-0.51). The c-statistic for all three equations ranged between 0.75 and 0.77 with no significant difference (P = 0.639 for c-statistic comparison). The MDRD equation seems to have a modest advantage over CKD-EPI and CG in estimating GFR and detecting impaired renal function in sub-Saharan African patients with Type 2 diabetes. The overall relatively modest correlation with CrCl, however, suggests the need for context-specific estimators of GFR or context adaptation of existing estimators.

Renal function is often estimated using one of several glomerular filtration rate (GFR) estimating equations. However, there is no consensus which estimating equation performs best in patients with advanced renal failure. We compared the performance of five different estimated GFR (eGFR) equations [Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease (CKD) Epidemiology collaboration (CKD-EPI) and Mayo Clinic and Lund-Malmö] with measured GFR (plasma iohexol clearance) in 2098 referred CKD patients with mGFR <30 mL/min/1.73 m(2). There were 398 patients with an mGFR ≤ 10 mL/min/1.73 m(2), 1974 with a measured GFR (mGFR) 11-20 mL/min/1.73 m(2) and 749 patients with mGFR 21-30 mL/min/1.73 m(2). Across the entire range, the median bias of eGFR was lowest for the Lund-Malmö equation (0.7 mL/min/1.73 m(2)), followed by the CKD-EPI (1.2 mL/min/1.73 m(2)), the MDRD (1.6 mL/min/1.73 m(2)), Mayo Clinic equation (1.7 mL/min/1.73 m(2)) and Cockcroft-Gault equation (4.6 mL/min/1.73 m(2)). The best accuracy within 30% of mGFR was also for Lund-Malmö (76%), while it was similar for CKD-EPI, MDRD and Mayo (65-67%). The Cockcroft-Gault had the worst accuracy of only ∼54%.The median bias was stable across mGFR categories, while the accuracy within 30% of mGFR became worse with decreasing mGFR. All equations performed best among patients with hereditary kidney diseases and tubulointerstitial disease. Accuracy was generally worse for patients >65 years of age and for those with diabetic nephropathy. In patients with advanced renal failure, the GFR-estimating equations show reasonably good performance on the population level. On the individual patient level, they are inaccurate, especially in elderly patients and those with diabetic nephropathy.

BackgroundAlthough the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation has been recommended for accurate estimates of glomerular filtration rate (eGFR), there is little information regarding differences in GFR estimates obtained using the Cockcroft-Gault (CG) or Modification of Diet in Renal Disease (MDRD) equations in East Asian cancer patients. We investigated discrepancies in GFR and toxicities in patients treated with cisplatin-based chemotherapy using three equations equations.MethodsA total of 229 patients were retrospectively recruited. We calculated eGFR using the three equations and separated patients into three categories based on GFR < 10 (group A), 10–50 (group B), and > 50 (group C) mL/min/1.73m2. We analyzed chemotherapy toxicities.ResultsThe mean eGFR calculated using the CG was the lowest of the values derived using the three equations. Estimates using the MDRD and CKD-EPI equations resulted in reclassifying 32 (71.1%) and 33 (73.3%) of 45 patients, originally placed in group B using the CG into group C. However, only 1 (7.7%) of 13 patients placed in group B using the MDRD were reclassified into group C using the CKD-EPI. Twenty-eight of 45 patients classified into group B using the CG equation were treated with reduced doses of cisplatin. However, these patients did not show significant differences in toxicities compared with other patients taking full doses of cisplatin.ConclusionThe CG equations underestimated GFR compared to the MDRD and CKD-EPI equations. Therefore, when GFR is estimated using CG equations, East Asian cancer patients may receive insufficient doses of chemotherapeutic agents, including cisplatin.

Background and Aims Glomerular filtration rate (GFR) is the most important and accurate parameter of kidney function in the course of chronic kidney disease (CKD). Renal or plasma inulin, diethylenetriaminepentaacetate (DTPA), ethylenediaminetetraacetate (EDTA), radiocontrast agents (iohexol, iothalamate) and some other substances clearances are the reference methods for determining GFR. However, these methods cannot be applied routinely because of the inconvenience. Several available methods have been developed to estimate GFR in a simpler manner and at low costs. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation is widely used to evaluate the GFR in practice. However, this equation is not accurate for the full age spectrum. In 2016, the new equation, full age spectrum equation, based on the serum creatinine (FAScr), was developed and can be applicable to all ages. However, data on the benefits of using the FAScr-method in different populations are contradictory. In particular, it is unclear whether the FAScr provides any advantages over the CKD-EPI method in adults. In this regards, we attempted to compare data obtained FAScr method with results some non-reference and reference methods in adult Russian population. Method We examined 120 Caucasian patients (M:F - 52:68; age 18-76 year) with CKD 1 - 5 stages. Patients with nephrotic syndrome and congestive heart failure were excluded. GFR (reference method) measured by plasma clearance of 99mTc-DTPA (CDTPA). CDTPA determined by one- compartment model 2-4 h method using a Chantler-Barratt linear correction. Estimation GFRs (eGFR) were established by Cockcroft-Gault creatinine clearance (CG), CKD-EPI (creatinine), FAScr and Modification of Diet in Renal Disease (MDRD) methods. Also, renal creatinine clearance (Ccr; UV/P method) was measured. Only GFRs values corrected on 1.73 m2 body surface area had been use. Results The values of GFR (Mean(SEM)) are: CDTPA 67.0(2.46); FAS 69.7(2.50); CKD-EPI 64.3(2.54); MDRD 60.9(2.62); CG 77.6(3.31); Ccr 85.2(3.40), мл/мин/1.73 m2. MDRD was significantly lower (paired Student t-test with correction on multiply comparison by Benjamini-Hochberg method) than CDTPA (P=0.0024), CG (P=0.0001) or Ccr (P&amp;lt;0.0001) were significantly higher. The bias (CDTPA minus non reference GFR) were: FAS -2.67(1.71); CKD-EPI 2.72(1.58); MDRD 6.12(1.78); CG -10.57(2.51); Ccr -18.22(2.26), ml/min. All biases are significantly differ between themselves (P from 0.00064 to &amp;lt;0.000001). The percentage of P30 of the FAS 81.6(3.5) was not significant differ from P30 of CKD-EPI (78.3(3.8); P=0.524) or MDRD (71.7(4.1); P=0.071). However, P30 of CG (67.5(4.3),%; P=0.01) or Ccr (54.2(5.42),%; P&amp;lt;0,001) were significant lower, than P30 of FAS. There were significant comparable direct correlations between CDTPA and FAS (r=0.764), CKD-EPI (r=0.801), MDRD (r=0.756), CG (r=0.656), Ccr (r=0.749); P&amp;lt;0.00001 in all cases. Conclusion In adult Russian population FAScr-method of GFR estimation had not any advantage over CKD-EPIcr-method.

Should Estimated Glomerular Filtration Rate Be Adjusted for Race?

Background: This paper aims to evaluate the concordance between the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula and alternative equations and to assess their predictive power for all-cause mortality in unselected patients discharged alive from a cardiology ward. Methods: We retrospectively included patients admitted to our Cardiology Division independently of their diagnosis. The total population was classified according to Kidney Disease: Improving Global Outcomes (KDIGO) categories, as follows: G1 (estimated glomerular filtration rate (eGFR) ≥90 mL/min/1.73 m2); G2 (eGFR 89–60 mL/min/1.73 m2); G3a (eGFR 59–45 mL/min/1.73 m2); G3b (eGFR 44–30 mL/min/1.73 m2); G4 (eGFR 29–15 mL/min/1.73 m2); G5 (eGFR <15 mL/min/1.73 m2). Cockcroft-Gault (CG), CG adjusted for body surface area (CG-BSA), Modification of Diet in Renal Disease (MDRD), Berlin Initiative Study (BIS-1), and Full Age Spectrum (FAS) equations were also assessed. Results: A total of 806 patients were included. Good agreement was found between the CKD-EPI formula and CG-BSA, MDRD, BIS-1, and FAS equations. In subjects younger than 65 years or aged ≥85 years, CKD-EPI and MDRD showed the highest agreement (Cohen’s kappa (K) 0.881 and 0.588, respectively) while CG showed the lowest. After a median follow-up of 407 days, overall mortality was 8.2%. The risk of death was higher in lower eGFR classes (G3b HR4.35; 95%CI 1.05–17.80; G4 HR7.13; 95%CI 1.63–31.23; G5 HR25.91; 95%CI 6.63–101.21). The discriminant capability of death prediction tested with ROC curves showed the best results for BIS-1 and FAS equations. Conclusion: In our cohort, the concordance between CKD-EPI and other equations decreased with age, with the MDRD formula showing the best agreement in both younger and older patients. Overall, mortality rates increased with the renal function decreasing. In patients aged ≥75 years, the best discriminant capability for death prediction was found for BIS-1 and FAS equations.

To evaluate diagnostic performance of glomerular filtration rate (GFR) estimated by modification of diet in renal disease (MDRD), chronic kidney disease epidemiology collaboration (CKD-EPI), full age spectrum (FAS), and revised Lund-Malmö (r-LM) equations in adults with diabetes. Individuals were included in this cross-sectional study if they had at least 1 measurement of technetium-99m diethylenetriamine-pentaacetic acid (99mTc-DTPA) GFR (mGFR) and serum creatinine (1487 patients with 2703 measures). GFR calculated by estimation equations was compared with mGFR. Diagnostic performance was assessed using concordance correlation coefficient (CCC), bias, precision, accuracy, reduced major axis regression (RMAR), and Bland-Altman plot. Analysis was repeated in subgroups based on sex, diabetes type, Hemoglobin A1C, and GFR level. Of all patients, 1189 (86%) had type 2 diabetes. Mean mGFR, MDRD, CKD-EPI, FAS, and revised Lund-Malmö eGFR were 66, 72, 74, 71, and 67 mL/min/1.73m2, respectively. Overall, the r-LM had the highest CCC (0.83), lowest bias (-1.4 mL/min/1.73 m2), highest precision (16.2 mL/min/1.73 m2), and highest accuracy (P10 = 39%). The RMAR (slope, intercept) in r-LM, FAS, MDRD, and CKD-EPI was 1.18, -13.35; 0.97, -2.9; 1, -6.4, and 1.04, -11.3, respectively. The Bland-Altman plot showed that r-LM had the lowest mean difference and the narrowest 95% limit of agreement (-1.0, 54.1 mL/min/1.73 m2), while mean difference was more than 5-fold higher in FAS, MDRD, and CKD-EPI (-5.2, -6.3, and -8.2, respectively). In adults with diabetes the revised Lund-Malmö performs better than MDRD, CKD-EPI, and FAS in calculating point estimates of GFR.

The influence of pharmaceutically induced weight changes on estimates of renal function: A patient-level pooled analysis of seven randomised controlled trials of glucose lowering medication

Comparison of the CKD Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) Study Equations: Risk Factors for and Complications of CKD and Mortality in the Kidney Early Evaluation Program (KEEP)

CHARLOTTE, N.C. — The two predominant equations used to stage chronic kidney disease give significantly different results in elderly people, suggest data compiled on 1,535 hospitalized patients with an average age of 79 years. Thiruvinvamalai S. Dharmarajan, MD, of Montefiore Medical Center in New York City and his colleagues analyzed data from hospitalized older adults with chronic kidney disease using the Modification of Diet in Renal Disease (MDRD) equation and the Cockcroft-Gault (C-G) equation to determine each patient's stage of disease. Nearly half the patients had come to the hospital from nursing homes. The G-C approximates glomerular filtration rate by calculating creatinine clearance from age, sex, body weight, and serum creatinine. In contrast, the MDRD calculates glomerular filtration rate using age, sex, race, and serum creatinine. Neither equation has been well validated in patients older than 70 years, Dr. Dharmarajan noted. The researchers found that the equations placed many patients in different disease stages. For example, the C-G indicated that 10% of the patients had stage I disease, whereas the MDRD put that number at 23%. The proportions of patients in stages II through V were 25%, 44%, 16%, and 5%, respectively, using the G-C versus 38%, 28%, 6%, and 5%, respectively, using the MDRD. The study findings were presented in a poster at the Annual Symposium. The two equations also yielded different results in a subset of 562 patients whom primary care physicians had diagnosed as having “renal insufficiency.” In this subgroup, the C-G placed 19%, 52%, and 29% in stages II, III, and IV of disease, respectively, whereas the MDRD put 9%, 39%, and 52% in those respective categories. In this group, as in the overall population, the discrepancy between the two measures increased dramatically with age. About half the patients with decline in kidney function may be poorly staged, monitored, and evaluated depending on which formula is used, the researchers wrote. “Perhaps this is an indication for further modification of existing formulae or the need for new methodology,” the researchers said. A new formula based on the MDRD has been developed by the Chronic Kidney Disease Epidemiology Collaboration, but it has yet to be validated in older patients, they added. The team declared no conflict of interest related to this study.

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

World Health Organization (WHO) predicts Indonesia's population with Type 2 Diabetes Mellitus (T2DM) will rise from 8.4 million in 2000 to 21.3 million in 2030. The primary cause of disability and death in people with Diabetes Mellitus (DM) is nephropathy. The early stages of diabetic nephropathy are characterized by glomerular hyperfiltration and an increase in the estimated-Glomerular Filtration Rate (eGFR). Other markers of diabetic nephropathy in addition to eGFR are increased creatinine, albuminuria, and proteinuria. The currently developed formulas for eGFR assessment are the Cockcroft-Gault (CG) formula, the Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI). This study aimed to determine the relationship between eGFR using the CKD-EPI formula for serum creatinine and CG in T2DM patients. Fifty-three DM patients participated in a cross-sectional study of the population of patients diagnosed with T2DM by clinicians at Hasanuddin University Hospital between March and June 2022. Version 25 of the Statistical Package for Social Science (SPSS) software was used to analyze the data. Statistical tests for the Normality of data distribution used the Kolmogorov-Smirnov test to determine the normality of data, the ANOVA test was used for comparison, and the Spearman test was used as a correlation test. The relationship between CKD-EPI and CG was highly correlated (r=0.868, p&lt;0.001). Urine albumin levels and eGFR CKD EPI (r= -0.283, p=0.042) and CG (r= -0.282, p=0.043) showed a significant connection. There was a very strong relationship between CKD-EPI and CG.

BackgroundNo studies have examined the practicality of the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiological Collaboration (CKD-EPI) and Berlin Initiative Study 1 (BIS1) equations for the estimated glomerular filtration rate (eGFR) in a large sample of centenarians. We aim to investigate the differences among the equations and suggest the most suitable equation for centenarians and near-centenarians.MethodsA total of 966 centenarians and 787 near-centenarians were enrolled, and the eGFR was calculated using the three equations mentioned above. Agreement among the equations was investigated with the κ statistic and Bland–Altman plots. Sources of discrepancy were investigated using a partial correlation analysis.ResultsThe three equations for assessing eGFR are not considered interchangeable in centenarians and near-centenarians. Δ(MDRD, CKD-EPI) and Δ(MDRD, BIS1) increased with age, but Δ(CKD-EPI, BIS1) was relatively stable with age. Δ(MDRD, CKD-EPI) and Δ(MDRD, BIS1) were considerable in subjects with Scr levels less than 0.7 mg/dL and decreased with the Scr level. A considerable difference between CKD-EPI and BIS1 was observed for participants with Scr levels ranging from 0.5 to 1.5 mg/dL. This difference increased with Scr levels ranging from 0.5 to 0.7 mg/dL, was relatively stable for Scr levels ranging from 0.7 to 0.9 mg/dL, and decreased with Scr levels ranging from 0.9 to 1.5 mg/dL. The differences in the three comparisons were all greater in women than in men (p < 0.05).ConclusionsWe tend to suggest the MDRD equation to calculate the glomerular filtration rate (GFR) in elderly individuals >95 years old who have no risk factors for cardiovascular disease; the BIS1 equation to calculate the eGFR for elderly individuals younger than 94 years old who have risk factors for cardiovascular disease; the CKD-EPI equation to calculate the eGFR of elderly individuals with Scr levels greater than 1.5 mg/dL; and the BIS1 equation to calculate the eGFR of older women with Scr levels less than 0.7 mg/dL.