MDRD Equation Research Articles

Association of Dyslipidemia with Renal Risk Factors eGFR, Proteinuria, Anemia, C-reactive Protein

Background: Dyslipidemia, characterized by abnormal lipid profiles, is a significant risk factor for cardiovascular disease and has been increasingly implicated in the progression of chronic kidney disease (CKD). Dyslipidemia contributes to endothelial dysfunction, oxidative stress, and inflammation, potentially exacerbating renal impairment. However, the association between dyslipidemia and key renal risk factors—estimated glomerular filtration rate (eGFR), proteinuria, anemia, and C-reactive protein (CRP)—in renal transplant recipients remains inadequately explored. Objective: To assess the association between dyslipidemia and renal risk factors, including eGFR, proteinuria, anemia, and CRP, in renal transplant recipients. Methodology: A cross-sectional observational study was conducted at Sir Salimullah Medical College & Mitford Hospital, the CKD and Urology Hospital (CKD&U), and the Kidney Foundation Hospital and Research Institute, Bangladesh, over 13 months (May 2019–June 2020). A total of 105 renal transplant recipients were included through purposive sampling. Demographic, clinical, and laboratory data were collected, including fasting lipid profiles, serum creatinine, fasting blood glucose, urinary albumin-to-creatinine ratio (ACR), CRP, and eGFR (calculated using the MDRD equation). Statistical analysis was performed using SPSS v16, applying Chi-square tests to evaluate associations between dyslipidemia and renal risk factors. Results: Among renal transplant recipients, 61.9% had elevated triglycerides, 53.3% had high LDL, 33.3% had elevated total cholesterol, and 61.0% had low HDL. The mean triglyceride level was 214.38 ± 128.33 mg/dL, and the mean LDL was 100.41 ± 36.31 mg/dL. Dyslipidemia was significantly associated with reduced eGFR (p=0.04), indicating a decline in renal graft function. Lower ApoA1 levels were significantly linked to elevated CRP (p=0.01) and reduced eGFR (p=0.043), while higher ApoB levels were also associated with reduced eGFR (p=0.038). Hypertriglyceridemia was significantly correlated with anemia (p=0.05). However, no significant associations were observed between lipid markers and proteinuria, hypertension, or diabetes. Conclusion: Dyslipidemia, particularly elevated triglycerides and low HDL levels, is significantly associated with reduced renal function and systemic inflammation in renal transplant recipients. Specific lipid markers, such as ApoA1 and ApoB, may play a critical role in predicting renal dysfunction and inflammatory status. Early detection and management of dyslipidemia may be crucial in preserving renal function and improving long-term transplant outcomes.

Quality of life and kidney function in CKD patients: a longitudinal study.

In chronic kidney disease (CKD), a declining glomerular filtration rate (GFR) leads to physiological and psychosocial burdens that impair quality of life (QoL). However, this relationship has been mainly investigated in cross-sectional studies and a limited number of longitudinal studies that reported contrasting results. This longitudinal study included 582 patients with Stages 2-5 CKD. QoL was assessed using the Kidney Disease Quality of Life (KDQOL™) instrument at baseline and annually for 3 years. GFR was estimated using the MDRD equation, the equation recommended by guidelines that were contemporary to the study cohort. We analysed the relationship between repeated measures of QoL and GFR using unadjusted and adjusted mixed linear models (MLMs). The cohort had a mean age of 61±12 years, with 60% males and 33% diabetics. Baseline eGFR was 36±13ml/min/1.73 m². Physical and mental component summary scores of QoL were 43.5 and 45.1, respectively. In MLM analyses adjusted for potential confounders, a 10ml/min/1.73 m² decrease in eGFR was significantly associated with reductions in physical (β=-0.60, P=.016) and mental (β=-0.52, P=.045) component summary scores over the follow-up period. The physical functioning and role limitation physical health subcomponents of QoL were primarily responsible for these associations. This longitudinal study shows that declining kidney function is associated with deteriorating QoL in CKD patients independently of other factors. These findings support the current KDIGO recommendation that regular monitoring of QoL should be incorporated into clinical practice to improve patient outcomes.

Importance of Glomerular Filtration Rate Determination and its Role in Drug-Dose Adjustments with Special Reference to Oncology

Glomerular filtration Rate (GFR) measured in steady state is the best marker of kidney function. Glomerular filtration rate can be determined using exogenous markers like inulin, iothalamate, or iohexol (mGFR), or estimated using endogenous markers like creatinine and cystatin C (eGFR). Several equations are available, CKD-EPI equation is the recommended equation as per current guidelines. CKD-EPI creatinine equation refit (without the race variable) – 2021, and CKD-EPI creatinine - cystatin C equation refit (without the race variable)-2021 are the most recent recommendations from the National Kidney Foundation and the American Society of Nephrology. Dose modifications of many drugs are needed in kidney dysfunction. In chronic kidney disease, as the kidney function is stable, determination of GFR is more accurate and can be used to modify the drug doses. Since the kidney function is not stable in acute kidney injury, determination of GFR is more difficult and it is not accurate. This makes it difficult to use it for determining dose modifications of drugs. Therapeutic drug level monitoring, and adjusting the dose based on pharmacokinetics/pharmacodynamics knowledge of the drug could be helpful in such cases. In oncology, accurate GFR measurement is crucial for adjusting the doses of chemotherapeutic agents to avoid toxicity and ensure efficacy, as cancer patients often have compromised kidney function due to the disease or its treatment. In this manuscript, we review all these aspects to provide a comprehensive understanding of GFR measurement and its implications in drug-dose adjustments, with a particular focus on how accurate GFR assessment is essential for optimizing chemotherapy dosing in oncology patients to minimize toxicity and maximize therapeutic efficacy. Frequently, medical professionals need to depend on online calculators to get the value of eGFR, as these equations can be complicated. Scientific calculators can be used too, but that is not a common practice in nephrology clinics. The authors have shown in this paper how to use Microsoft Excel to create personal calculators, so that eGFR may be calculated by medical professionals and dialysis staff even when internet is not available due to institutional policies or otherwise. The ‘Appendix’ section given at the end of the paper shows how to create these personal calculators in Microsoft excel. Calculators for CKD-EPI equations can also be developed in excel, however the calculations are more complex, so I prefer using the programming language python to develop these calculators. In this paper, the authors have shown only the excel based calculators for CG equation and MDRD-4 (re-expressed) equation.

Prevalence and factors linked to renal involvement in prediabetes patients across Europe in the ePREDICE trial

This sub-analysis of the ePREDICE trial, investigated the prevalence and determinants of renal complications, specifically glomerular hyperfiltration, albuminuria, and reduced kidney function, in individuals with prediabetes (PD). The cohort consisted of 967 participants from diverse backgrounds across seven countries. The kidney function was evaluated using the MDRD-4 equation, and the influence of various clinical and demographic factors on renal involvement was assessed by multivariable regression models. Additionally, insulinogenic and disposition indices were examined. Overall, the prevalence of renal abnormalities in this PD cohort was 9.2% (n = 89). Key findings included the detection of hyperfiltration in 20 (2%) individuals, albuminuria in 45 (4.7%), and CKD stage G3a in 29 (3%). Hyperfiltration was inversely correlated with age and height, while albuminuria showed a significant direct association with the disposition index (DI). Age and waist circumference were significantly and directly associated with estimated glomerular filtration rate (eGFR). The ePREDICE study highlights critical factors that affect renal involvement in PD individuals, revealing complex interactions among various parameters. These findings further emphasize the necessity for the search of early kidney abnormalities in people with PD especially in those in older age groups and with a large waist circumference.

Adoption of CKD-EPI (2021) for Glomerular Filtration Rate Estimation: Implications for UK Practice

Introduction: Recommendations to move to a race-free estimating equation for glomerular filtration rate (GFR) have gained increasing prominence since 2021. We wished to determine the impact of any future adoption upon the chronic kidney disease (CKD) patient population of a large teaching hospital, with a population breakdown largely similar to that of England as a whole. Methods: We compared four estimating equations (Modification of Diet in Renal Disease [MDRD], CKD-EPI [2009], CKD-EPI [2021], and European Kidney Function Consortium [EKFC]) using the Bland-Altman method. Bias and precision were calculated (in both figures and percentages) for all patients with CKD and specific subgroups determined by age, ethnic group, CKD stage, and sex. CKD stage was assessed using all four equations. Results: All equations studied had a positive bias in South Asian patients and a negative bias in black patients compared to CKD-EPI (2021). Similarly, there was a positive bias in white patients across all equations studied. Comparing CKD-EPI (2009) and EKFC, this positive bias increased as patients aged; the opposite was seen with MDRD. Between 10% and 28% of patients in our dataset changed their CKD staging depending upon the estimating equation used. Discussion: Our work confirms previous findings that the MDRD equation overestimates estimated GFR (eGFR) in South Asians and underestimates eGFR in blacks. The alternative equations also demonstrated similar bias. This may, in part, explain the health inequalities seen in ethnic minority patients in the UK. Applying our findings to the UK CKD population as a whole would result in anywhere from 260,000 to 730,000 patients having their CKD stage reclassified, which in turn will impact secondary care services.

Estimates of eskd risk and timely kidney replacement therapy education

BackgroundKidney replacement therapy (KRT) needs preparation and its timing is difficult to predict. Nephrologists’ predictions of kidney failure risk tend to be more pessimistic than the Kidney Failure Risk Equation (KFRE) predictions. We aimed to explore how physicians’ risk estimate related to referral to KRT education, vs. the objective calculated KFRE.MethodsProspective observational study of data collected in chronic kidney disease (CKD) clinics of the Veterans Affairs Medical Center San Diego and the University of California, San Diego. The study included 257 participants who were aged 18 years or older, English speaking, prevalent CKD clinic patients, with estimated glomerular filtration rate (eGFR) < 60 mL/min per 1.73 m2 (MDRD equation). The exposure consisted of end stage kidney disease (ESKD) risk predictions. Nephrologists’ kidney failure risk estimations were assessed: “On a scale of 0–100%, without using any estimating equations, give your best estimate of the risk that this patient will need dialysis or a kidney transplant in 2 years.” KFRE was calculated using age, sex, eGFR, serum bicarbonate, albumin, calcium, phosphorus, urine albumin/creatinine ratio. The outcomes were the pattern of referral to KRT education (within 90 days of initial visit) and kidney failure evaluated by chart review. The population was divided into groups either by nephrologists’ predictions or by KFRE. Referral to KRT education was examined by group and sensitivity and specificity were calculated based on whether participants reached kidney failure at 2 years.ResultsA fifth were referred for education by 90 days of enrollment. Low risk patients by both estimates had low referral rates. In those with nephrologists’ predictions ≥ 15% (n = 137), sensitivity was 71% and specificity 76%. In those with KFRE ≥ 15% (n = 55), sensitivity was 85% and specificity 41%.ConclusionsAlthough nephrologists tend to overestimate patients’ kidney failure risk, they do not appear to act on this overestimation, as the rates of KRT education referrals are lower than expected when a nephrologist identifies a patient as high risk.Clinical Trial NumberNot applicable

Association of Inflammatory Marker C-Reactive Protein and Interleukin-6 with Stages 3-5 of Chronic Kidney Disease

Background: Despite different strategy to retard the progression of CKD, majority still progress to ESRD. Other than conventional risk factors inflammation is considered as one of the reversible factors responsible for CKD progression which can be intervened. Therefore, we have studied the level of inflammatory marker CRP and IL-6 at stages 3-5 of CKD patients and their association with CKD stage progression determined by eGFR. Methods: We have conducted a cross sectional study among 150 CKD patients and 32 healthy controls at OPD of Nephrology department of National Institute of Kidney Diseases and Urology, Dhaka from January`2016 to December`2016. Purposive sampling method was the tool for case selection and CKD was defined as eGFR &lt;60ml/min/1.73m2. AKI, history of dialysis, kidney transplant, patients having acute infection, malignancy or liver disease, received chemotherapy or immunotherapy (&lt;6 months) and patients with connective tissue disease were the exclusion criteria. Fasting blood glucose, Hb%, serum Ca++, serum PO4, serum total cholesterol and serum triglyceride level were measured for both case and controls. eGFR has been calculated using MDRD equation. For the cases CRP had been measured on two occasions at an interval of one and half month. Those cases who had raised CRP level in both occasions were selected for measurement of IL-6 from second sample. CRP had been measured by turbidimetry method using fully automated chemistry analyzer. IL-6 had been measured using enzyme linked immunosorbent assay (ELISA) based on the Biotin double antibody sandwich technology. Scatter diagram and multiple regression models were used to examine the association between CRP and IL-6 with stage 3-5 of CKD denoted by eGFR. Results: The mean of CRP were 9.5±2.7 mg/L in CKD patients vs. 2.9±0.5 mg/L in controls without CKD and the mean of IL-6 were 29.5±13.0 pg/ml in CKD patients vs. 3.3±0.3 pg/ml in controls without CKD. Both were elevated and significant statistically (p=.001). Scatter diagram showing correlation coefficient (r value) -0.592 and -0.615 for eGFR vs. CRP and eGFR vs. IL-6 respectively which indicate both are negatively correlated with eGFR. But IL-6 had a more strong negative correlation. Multiple regression analysis shows regression co efficient (B) for CRP and IL-6 is -1.251 and -2.826 respectively after taking into account other factors which can alter eGFR level (age, Hb%, serum Calcium, S. Total Cholesterol, S.PO4, S. Triglyceride) that indicates in the prediction of eGFR, IL-6 had significant negative association than CRP after adjusting the conventional factors responsible for CKD progression. Conclusion: Our data suggest that though CRP and IL-6 both are significantly raised in advanced CKD stage 3-5, IL-6 is more rapidly increasing and more strongly associated than CRP with the severity of CKD measured by eGFR.

Assessment of impaired glomerular filtration rate and associated factors in South West Ethiopia: a cross-sectional study

IntroductionCurrently, kidney disease is an increasing major health problem worldwide. It is expected to be the 5th ranked cause of death by 2040. If it is early detected, further complication caused by kidney disease will be minimized. An assessment of impaired glomerular filtration rate (eGFR) has potential aids in early identification and treatment of kidney disease. However, in hospital practice instead of using eGFR, direct measurement of serum creatinine level is used for assessing renal function. Hence, this study is aimed to assess the magnitude and associated factors of impaired glomerular filtration rate among admitted patients in Wolkite University Specialized Teaching Hospital (WKUSTH).ObjectiveTo assess the magnitude and associated factors of impaired glomerular filtration rate in WKUSTH, Ethiopia 2023.MethodInstitutional based cross-sectional study with secondary data was conducted. 338 participants were selected by a convenient sampling technique. Epidata 3.1 version for data entry and SPSS version 20 for data analysis was used. Bivariate analysis was used to screen candidate variables for multivariate analysis. In the multivariate analysis a P-value < 0.05 were considered statistically significant.ResultsThe study enrolled 338 patients admitted to WUSTH. Seventy (20.7%) (95% CI: 16.6–25.4%) of them had impaired eGFR according to Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and Modification of Diet in Renal Disease (MDRD-4). older age (AOR 3.38, 95% CI; 1.31, 8.71), hypertension (AOR 17.8, 95% CI; 7.75, 41.22), anemia (AOR 2.51, 95% CI; 1.11, 5.83) DM (AOR 11.2, 95% CI; 4.11, 30.73), and high BMI (AOR 7.56, 95% CI; 3.16, 18.08), were independently associated with impaired eGFR.ConclusionsThe magnitude of impaired eGFR was prevalent among adult patients admitted to WKUSTH medical ward with different medical conditions. Old age, Hypertension, Diabetes, high body mass index, and Anemia were significantly associated with impaired eGFR both in CKD-EPI and MDRD-4 equation. Estimation of GFR for all hospitalized adults with known CKD risk factors might help in early detection of CKD and prevent complications.

Cisplatin eligibility in the neoadjuvant setting of patients with muscle-invasive bladder cancer undergoing radical cystectomy.

To examine the agreement of different calculated estimated glomerular filtration rate (eGFR) formulas and measured creatinine clearance (CrCI) at the primary diagnosis of muscle-invasive bladder cancer (MIBC). We performed a multicenter analysis of patients with MIBC, treated with cisplatin-based neoadjuvant chemotherapy (NAC) and radical cystectomy (RC), or with RC alone, between 2011 and 2021. Baseline eGFR was computed using 4 calculated serum equations including Cockcroft-Gault (CG), MDRD, CKD-EPI 2009, and race-free CKD-EPI 2021. To examine the association between calculated eGFR and measured CrCI, subgroup analyses were performed among patients in whom measured 24-hour urine CrCl was determined. Cisplatin-ineligibility was defined as CrCI and/or eGFR < 60 mL/minute per 1.73 m2. Of 956 patients, 30.0%, 33.3%, 31.9%, and 27.7% were found to be cisplatin-ineligible by the CG, MDRD, CKD-EPI, and race-free CKD-EPI equations (P = .052). The concordance between calculated eGFR formulas was rated substantial (Cohen's kappa (k): 0.66-0.95). Among the subgroup (n = 245) with measured CrCl, 37 (15.1%) patients had a CrCI less than 60 mL/minute. Concordance between measured CrCl and calculated eGFR was poor (ĸ: 0.29-0.40). All calculated eGFR formulas markedly underestimated the measured CrCI. Specifically, 78%-87.5% of patients with a calculated eGFR between 40 and 59 mL/minute exhibited a measured CrCI ≥ 60 mL/minute. Comparing calculated eGFR formulas, similar percentages of patients with MIBC were deemed cisplatin-ineligible. However, a significant number of patients could be upgraded by being cisplatin-fit based on measured CrCI, particularly when the calculated eGFR was falling within the gray range of 40-59 mL/minute.

The Relationship of Certain Physiological Parameters and VEGF with chronic kidney disease

Chronic kidney disease (CKD) is a major health burden affecting over 10% of the global population. As kidney function deteriorates across progressive CKD stages, systemic inflammation and cytokine activity are upregulated which further drive disease advancement. Vascular endothelial growth factor (VEGF) also becomes increasingly dysregulated with implications for vascular pathology. However, step-wise changes in these pathways correlating with declining renal filtration have not been clearly elucidated : Objective: This study aimed to evaluate the utility of estimated glomerular filtration rate (eGFR) using the MDRD equation for disease staging, and to explore potential non-invasive biomarkers, including inflammatory markers and vascular endothelial growth factor (VEGF) expression, for early prediction of renal dysfunction; Methods: 50 CKD patients categorized into stages 1-4 (n=10 each) and 10 healthy controls were recruited. Serum creatinine was measured enzymatically and eGFR calculated. Plasma TNF-alpha and CRP concentrations were determined by ELISA. Relative VEGF mRNA levels were quantified by RT-qPCR and normalized to GAPDH; Results: Advancing CKD stage showed step-wise increases in serum creatinine (p&lt;0.001) and reductions in mean eGFR (p&lt;0.001). TNF-alpha and CRP also demonstrated significant stage-dependent elevations beginning from early stage 2 disease relative to controls (p&lt;0.01). VEGF expression escalated progressively from ~3 fold in stage 2 to ~129 fold in stage 4 CKD compared to normal individuals (p&lt;0.001); Conclusions: Deteriorating renal function is associated with substantive aggravations in systemic inflammation and VEGF expression. Tracking these biomarkers could enable early detection of underlying pathology prior to onset of severe kidney impairment.

The Relationship of Certain Physiological Parameters and VEGF with chronic kidney disease

Chronic kidney disease (CKD) is a major health burden affecting over 10% of the global population. As kidney function deteriorates across progressive CKD stages, systemic inflammation and cytokine activity are upregulated which further drive disease advancement. Vascular endothelial growth factor (VEGF) also becomes increasingly dysregulated with implications for vascular pathology. However, step-wise changes in these pathways correlating with declining renal filtration have not been clearly elucidated : Objective: This study aimed to evaluate the utility of estimated glomerular filtration rate (eGFR) using the MDRD equation for disease staging, and to explore potential non-invasive biomarkers, including inflammatory markers and vascular endothelial growth factor (VEGF) expression, for early prediction of renal dysfunction; Methods: 50 CKD patients categorized into stages 1-4 (n=10 each) and 10 healthy controls were recruited. Serum creatinine was measured enzymatically and eGFR calculated. Plasma TNF-alpha and CRP concentrations were determined by ELISA. Relative VEGF mRNA levels were quantified by RT-qPCR and normalized to GAPDH; Results: Advancing CKD stage showed step-wise increases in serum creatinine (p&lt;0.001) and reductions in mean eGFR (p&lt;0.001). TNF-alpha and CRP also demonstrated significant stage-dependent elevations beginning from early stage 2 disease relative to controls (p&lt;0.01). VEGF expression escalated progressively from ~3 fold in stage 2 to ~129 fold in stage 4 CKD compared to normal individuals (p&lt;0.001); Conclusions: Deteriorating renal function is associated with substantive aggravations in systemic inflammation and VEGF expression. Tracking these biomarkers could enable early detection of underlying pathology prior to onset of severe kidney impairment.

A Comparison of Renal Effects between Empagliflozin and Linagliptin in Diabetic Patients with Chronic Kidney Disease: A Randomized Clinical Trial

Objective: The current study aimed to compare the renal effects of Empagliflozin with Linagliptin combined with Metformin in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease. combined with Metformin in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease. Materials and Methods: We conducted a randomized clinical trial on diabetic patients aged over 18 years with chronic renal failure and an EGFR between 20 to 60 ml/minutes/1.73 m2 corrected with the MDRD equation. Between January and December 2023, a total of 150 cases in Imam Hossein Hospital were randomized into two study arms of 75 cases receiving Empagliflozin (10 mg/day) and metformin or Linagliptin (5mg/day) and metformin for 6 months. The primary outcome was a change in chronic kidney disease (CKD) stage, while serum creatinine, fasting blood sugar (FBS), proteinuria, and blood pressure were evaluated at baseline, 3 and 6 months later. Results: The mean age of participants was 62.20 (± 4.45) years and 50% of them were females. Study indices including serum creatinine (P: 0.001), estimated glomerular filtration rate (eGFR) (P: 0.001), FBS (P: 0.001), HgA1c (P: 0.001), proteinuria (P: 0.001), and blood pressure (P: 0.001) reduced significantly over time in both groups. After adjustment for potential confounders, Empagliflozin reduced the level of serum creatinine independent of other factors. Conclusion: Empagliflozin significantly reduces the level of serum creatinine compared to Linagliptin in patients with T2DM and chronic renal failure.

Comparative Analysis of Seven Equations for Estimated Glomerular Filtration Rate and Their Impact on Chronic Kidney Disease Categorization in Korean Patients at Local Clinics and Hospitals.

(1) Background: Accurate estimation of the glomerular filtration rate (eGFR) is essential for the early detection of chronic kidney disease (CKD), targeted interventions, and ongoing monitoring. Although various equations for calculating eGFR exist, comparative studies on eGFR levels and the impact of these equations on CKD prevalence are limited in the Korean population. (2) Methods: We compared eGFR levels calculated using seven equations and investigated the prevalence of CKD through a retrospective analysis of the data from Korean adult patients who visited local clinics and hospitals and underwent simultaneous serum creatinine (Cr) and cystatin C (Cys-C) measurements. The equations analyzed were: 2006 MDRD, 2009 CKD-EPI Cr, 2012 CKD-EPI Cys-C, 2012 CKD-EPI Cr & Cys-C, 2021 CKD-EPI Cr, 2021 CKD-EPI Cr & Cys-C, and 2021 EKFC. (3) Results: This study included 6688 Korean patients (3736 men and 2952 women; median age: 61.4; IQR: 47.2-73.4). Among the equations, the median eGFR levels were the highest when using the 2021 CKD-EPI Cr & Cys-C equation (85.1 mL/min/1.73 m2) and the lowest when using the 2006 MDRD equation (73.4 mL/min/1.73 m2). The highest prevalence of decreased eGFR < 60 mL/min/1.73 m2 (equivalent to or worse than G3a CKD) was noted with the 2012 CKD-EPI Cys-C equation (32.4%), while the lowest was with the 2021 CKD-EPI Cr equation (22.9%), resulting in a maximum prevalence difference of 9.5%. (4) Conclusions: The prevalence of CKD varies based on the eGFR equation used and the patient's age. Equations that include Cys-C may identify a larger number of patients with decreased kidney function.

Comparison of the applicability of seven calculation equations of glomerular filtration rate among elderly people in China

BackgroundAt present, estimated glomerular filtration rate (eGFR) remains the most frequently utilized parameter in the evaluation of kidney injury severity. Numerous equations have been formulated based on serum creatinine (Scr) or serum cystatin C (Cysc) levels. However, there is a lack of consensus regarding the efficacy of these equations in assessing eGFR, particularly for elderly individuals in China. This study aimed to evaluate the applicability of the MDRD, MDRDc, CKD-EPI series, BIS1, and FAS equations within the Chinese elderly population.MethodsA cohort of 298 elderly patients with measured GFR (mGFR) was enrolled. The patients were categorized into three subgroups based on their mGFR levels. The eGFR performance was examined, taking into account bias, interquartile range (IQR), accuracy P30, and root-mean-square error (RMSE). Bland–Altman plots were employed to verify the validity of eGFR.ResultsThe participants had a median age of 71 years, with 167 (56.0%) being male. Overall, no significant differences in bias were observed among the seven equations (P > 0.05). In terms of IQR, P30, and RMSE, the BIS1 equation demonstrated superior accuracy (14.61, 72.1%, and 13.53, respectively). When mGFR < 30 ml/min/1.73 m2, all equations underestimated the true GFR, with the highest accuracy reaching only 59%. Bland–Altman plots indicated that the BIS1 equation exhibited the highest accuracy, featuring a 95% confidence interval (CI) width of 52.37.ConclusionsThis study suggested that the BIS1 equation stands out as the most applicable for estimating GFR in Chinese elderly patients with normal renal function or only moderate decline. 2020NL-085-03, 2020.08.10, retrospectively registered.

Advanced Oxidative Protein Products Had a Diagnostic Accuracy for Identifying Chronic Kidney Disease in Adult Population.

Chronic Kidney Disease (CKD) is a serious public health problem. Hyperglycemia stimulates the production of reactive oxygen species that cause oxidative damage to proteins. AOPPs constitute a group of oxidized dityrosine-containing proteins that are generated during periods of oxidative stress. They have proved to be a valuable early marker of oxidative tissue damage and active mediators of inflammation associated with the uremic state. To analyze if advanced oxidative protein products (AOPPs) have diagnostic accuracy for identifying chronic kidney disease (CKD) in the adult population. We conducted a diagnostic test validation study in 302 adults ≥20 years old, of both sexes, with and without T2D. After obtaining informed consent, a comprehensive clinical history, anthropometric measurements (weight, BMI) and blood pressure were recorded. Glucose, cholesterol, triglyceride, HDL-c, LDL-c and AOPPs were determinates. Glomerular filtration rate (GFR) was calculated using Cockcroft-Gault (C-G) corrected by body surface area (BSA, mL/min/1.73 m2), CKD-EPI and MDRD equations to identify five stages of CKD. This study follows the Standards for Reporting Diagnostic Accuracy Studies (STARD). The median value of AOPPs was 198.32 µmol/L (minimum-maximum value: 113.48-522.42 µmol/L). The group with patients diagnosed with T2D exhibited higher concentrations (median: 487.39 µmol/L) compared to the non-diabetic group (median: 158.50 µmol/L, p = 0.0001). The selected cut-off point was ≥200 µmol/L using the closest to the median value of AOPPs with sensitivity and specificity as follows: C-G: sensitivity 96.58%; specificity 80%; likelihood ratio: 4.83; CKD-EPI: sensitivity 95.76%; specificity 79.89%; likelihood ratio: 4.76; MDRD: sensitivity 86.55%; specificity: 73.22%; likelihood ratio: 3.23. A difference was observed between AOPPs and chronic kidney disease stage. This study provides evidence that AOPPs ≥ 200 µmol/L have diagnostic accuracy in identifying stage 4-5 CKD by C-G, MDRD and CKD-EPI equations in adults with and without T2D.

Validação das equações para estimativa da filtração glomerular ajustáveis por raça/cor em adultos de Vitória, Espírito Santo, Brasil

Abstract The assessment of renal function is performed using the glomerular filtration rate (GFR) whose measurement by creatinine clearance (ClCr) and is dependent on a 24-hour urine sample, hindering it use in primary healthcare. The equations that estimate GFR from serum creatinine make the test more accessible, however, their adjustments by race/color have been questioned in mixed populations. To test the agreement between CrCl and GFR estimated by formulas (Modification of Diet in Renal Disease [MDRD-4] and Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]), with or without adjusting for race/color, data were used from a sub-study of the National Health Survey (NHS) including 272 adults from Vitória/Espírito Santo who underwent a 24-hour urinary sampling. Analysis of variance (ANOVA) and the Bland-Altman method were adopted. There was adequate agreement between ClCr and equations, but the adjustment by race/color decreases the accuracy of both equations. In the race/color factor, there was similarity between groups for CrCl (p=0.21), suggesting that there is no difference in creatinine metabolism induced by skin color. It is concluded that MDRD and CKD-EPI equations perform satisfactorily in the evaluation of renal function, and the use of corrections for race/color is not recommended.

Validation of glomerular filtration estimation equations adjustable by race/colour in adults from Vitória, Espírito Santo, Brazil.

The assessment of renal function is performed using the glomerular filtration rate (GFR) whose measurement by creatinine clearance (ClCr) and is dependent on a 24-hour urine sample, hindering it use in primary healthcare. The equations that estimate GFR from serum creatinine make the test more accessible, however, their adjustments by race/color have been questioned in mixed populations. To test the agreement between CrCl and GFR estimated by formulas (Modification of Diet in Renal Disease [MDRD-4] and Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]), with or without adjusting for race/color, data were used from a sub-study of the National Health Survey (NHS) including 272 adults from Vitória/Espírito Santo who underwent a 24-hour urinary sampling. Analysis of variance (ANOVA) and the Bland-Altman method were adopted. There was adequate agreement between ClCr and equations, but the adjustment by race/color decreases the accuracy of both equations. In the race/color factor, there was similarity between groups for CrCl (p=0.21), suggesting that there is no difference in creatinine metabolism induced by skin color. It is concluded that MDRD and CKD-EPI equations perform satisfactorily in the evaluation of renal function, and the use of corrections for race/color is not recommended.

Correlation Between the C-G and MDRD Equations in Comparison to the CKD-EPI Equations in Geriatric Patients

Correlation Between the C-G and MDRD Equations in Comparison to the CKD-EPI Equations in Geriatric Patients

Comparison of GFR measurement with a two-blood sample technique using [99mTc]Tc-DTPA vs. creatinine-based equations in potential kidney donors.

Accurate determination of glomerular filtration rate (GFR) is crucial for selection of kidney donors. Nuclear medicine methods are considered accurate in measuring GFR but are not always easily available. The four-variable Modification of Diet in Renal Disease (MDRD4), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), and Full Age Spectrum (FAS) formulas are common equations for estimating GFR and are recommended for initial assessment of kidney donors. The aim of this study was to evaluate the performance of these GFR estimation equations compared with technetium-99m diethylenetriaminepentaacetic acid ([99mTc]Tc-DTPA) clearance. We compared GFR estimation by [99mTc]Tc-DTPA clearance using a two-blood sample method with estimation by MDRD4, CKD-EPI, and FAS creatinine-based equations in a population of healthy potential kidney donors. A total of 195 potential kidney donors (68.2% female; mean age 49 years, range 21-75 years) were included in this study. Mean [99mTc]Tc-DTPA measured GFR (mGFR) was 101.5 ± 19.1 mL/min/1.73 m2. All three equations underestimated the GFR value measured by [99mTc]Tc-DTPA (MDRD4: -11.5 ± 18.8 mL/min/1.73 m2; CKD-EPI: -5.0 ± 17.4 mL/min/1.73 m2; FAS: -8.3 ± 17.4 mL/min/1.73 m2). Accuracy within 30% and 10% of the measured GFR value was highest for CKD-EPI. The CKD-EPI equation showed better performance in estimating GFR in healthy potential kidney donors, proving to be a more accurate tool in the initial assessment of kidney donors. However, creatinine-based equations tended to underestimate kidney function. Therefore, GFR should be confirmed by another method in potential kidney donors.

Addition of bioimpedance-derived body cell mass improves performance of serum creatinine-based GFR estimation in a chronic kidney disease cohort.

Serum creatinine-based glomerular filtration rate (GFR) estimating equations are imprecise and systemic overestimate GFR in chronic kidney disease (CKD) populations with low muscle mass. Bioimpedance devices can measure body cell mass (BCM), a surrogate for muscle mass which has been included in a published GFR estimating equation. This BCM GFR equation is validated and compared with MDRD and CKD-EPI 2021 equations in an Indian CKD population. Patients with stable CKD stages 1-5 and voluntary kidney donors underwent measurement of serum creatinine, DTPA GFR and bioimpedance on the same day. BCM GFR was tested for consistency, agreement and performance with respect to DTPA GFR. A total of 125 study participants were enrolled, including 106 patients with CKD (Stage 1: 8; stage 2: 32, stage 3: 42, stage 4: 20 and stage 5: 4 patients) and 19 voluntary kidney donors, with 66% males, and a mean age of 43.3 (± 16.5) years. The median bias of BCM GFR was 5.45ml/min/1.73 m2 [95% confidence interval (CI) 4.2-8.3], absolute precision was 10.16ml/min/1.73 m2 [95% CI 4.5-12.6], P30 was 59.1% [95% CI 50.0-67.7] and accuracy was 8.62% [95% CI 6.4-20.0]. Kappa measurement of agreement was the highest for BCM GFR-based staging (0.628 vs 0.545 for MDRD and 0.487 for CKD-EPI). BCM-based GFR estimating equation performed better than MDRD and CKD-EPI equations in this Indian CKD population, and BCM GFR-based KDIGO staging was associated with lesser misclassification than the MDRD and CKD-EPI equations. Clinical Trials Registry of India (CTRI/2019/11/021850).