Chronic Kidney Disease Epidemiology Collaboration Equation Research Articles

Association between soft drinks intake and low glomerular filtration rate in Mexican adults: Results from RenMex

To evaluate the association between soft drinks (SDs) consumption and estimated glomerular filtration rate (eGFR) in a Mexican adult population. We used data from the RenMex consortium (n=2095) that included the Mexican Teachers Cohort Study (34-65 years), the Health Workers Cohort Study (18-90 years), and the Comitán Study (19-91 years). In this cross-sectional study, we assessed SDs consumption (cola and flavored soda) using a food frequency questionnaire (FFQ) and estimated eGFR using the CKD Epidemiology Collaboration equation. Quantile regression was used to assess the association between SDs consumption and eGFR with eGFR as a continuous variable. Multinomial logistic regression models were used for eGFR categories derived from quantile regression (mildly decreased eGFR, ≥72.9-87.9mL/min/1.73m2 and moderately decreased eGFR, <72.9mL/min/1.73m2). Mean age of study participants was 47.2 years, 67.5% were women, and 12.2% had diabetes. eGFR was <60mL/min/1.73m2 in 3.7% of study participants. Mildly decreased eGFR was present in 14.8%, and moderately decreased eGFR was present in 10.1% of study participants. Quantile regression results showed that SDs consumption was associated with lower eGFR at the 10th, 25th, 50th and 75th percentile. Based on the final adjusted multinomial model, ≥7 servings/week was positively associated with moderately decreased eGFR relative to <1 serving/week (Relative Risk Ratio=1.95; 95% CI: 1.07-3.57). Our results suggest that higher SDs consumption is associated with lower eGFR. Encouraging healthy dietary choices should be part of the management and prevention of CKD.

Assessment of the 2023 European Kidney Function Consortium (EKFC) equations in a Chinese adult population.

The European Kidney Function Consortium (EKFC) developed two novel equations in 2023 for estimating glomerular filtration rate (GFR): one sex-free cystatin C-based equation (EKFCCys) and one creatinine-cystatin C combined equation (EKFCCr-Cys). This study compared their performance with the previous creatinine-based EKFC equation (EKFCCr) and commonly used Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Berlin Initiative Study (BIS) equations in Chinese adults. A total of 2,438 Chinese adults (mean age=53.04 years) who underwent the 99mTc-DTPA renal dynamic imaging for reference GFR (rGFR) were included. Diagnostic value was evaluated using correlation coefficients, sensitivity, specificity, and area under the receiver operating characteristic curve (ROCAUC). Performance was assessed in terms of bias, precision (interquartile range of the median difference [IQR]), accuracy (percentage of estimates ±30 % of rGFR [P30], and root-mean-square error [RMSE]) across age, sex, and rGFR subgroups. Gender differences in bias and P30 were also analyzed. Average rGFR was 73.37 mL/min/1.73 m2. EKFC equations showed stronger correlations and larger AUCs compared to the parallel CKD-EPI equations, with EKFCCr-Cys demonstrating the greatest improvement (R=0.771, ROCAUC=0.913). Concerning bias, precision, and accuracy, EKFC equations consistently outperformed CKD-EPI equations. EKFCCr-Cys and EKFCCr performed acceptably well in the entire population and were equivalent to BIS equations in the elderly. All equations, including EKFCCys, showed similar P30 accuracy across sexes. EKFC equations provided a reasonable alternative for estimating GFR in the Chinese adult population. While EKFCCys did not outperform EKFCCr, EKFCCr-Cys improved the accuracy of single-marker equations.

Performance evaluation of Chronic Kidney Disease Epidemiology Collaboration equations for estimated glomerular filtration rate compared to inulin clearance in Koreans.

A race-free glomerular filtration rate (GFR) estimation equation has recently been developed. However, the performance of the new Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations needs to be evaluated in Asian populations. We performed a cross-sectional study at a single center in South Korea. The measured GFR (mGFR) was determined based on systemic inulin clearance. The GFR was estimated using the five CKD-EPI equations: 2009 CKD-EPIcr, 2012 CKD-EPIcr-cys, 2012 CKD-EPIcys, 2021 CKD-EPIcr, and 2021 CKD-EPIcr-cys. The performances of five estimated GFR (eGFR) equations were assessed by bias, precision, and accuracy (percentage of estimates within 30% of mGFR). The median mGFR and interquartile range (IQR) was 53.5 (32.4-80.0) mL/min/1.73 m2. The mGFR better correlated with 2009 CKD-EPIcr (ρ = 0.628) and 2021 CKD-EPIcr-cys (ρ = 0.806) than with 2021 CKD-EPIcr (ρ = 0.623) and 2012 CKD-EPIcr-cys (ρ = 0.801). The median bias of 2009 CKD-EPIcr and 2012 CKD-EPIcr-cys were lower than those of 2021 CKD-EPI equations (2009 CKD-EPIcr, 2.24 [IQR, -8.83 to 17.39] vs. 2021 CKD-EPIcr, 5.40 [IQR, -6.04 to 20.40]; 2012 CKD-EPIcr-cys, 6.74 [IQR, -2.81 to 20.80] vs. 2021 CKD-EPIcr-cys, 10.54 [IQR, 0.30-24.37]; all in mL/min/1.73 m2). The percentage of eGFR values within 30% of mGFR was higher in 2009 CKD-EPIcr and 2012 CKD-EPIcr-cys equations than 2021 CKD-EPI equations. The CKD prevalence in 2009 CKD-EPIcr, 2021 CKD-EPIcr, 2012 CKD-EPIcr-cys, and 2021 CKD-EPIcr-cys was 54.8%, 51.0%, 47.7%, and 44.8%, respectively. Our study demonstrated better performance of the original CKD-EPIcr and CKD-EPIcr-cys equations than the 2021 new CKD-EPI equations. We do not recommend the adoption of the new CKD-EPI equations in Korea.

Biological variation in the estimated glomerular filtration rate of healthy individuals within 24h calculated using 2021CKD-EPI equations.

Use the MDRD (Modification of Diet in Renal Disease) and 2021 CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation void of race coefficients (CKD-EPICrea, CKD-EPICys-C, and CKD-EPICrea+Cys-C) to estimate the BV (Biological variation) of eGFR (estimated glomerular filtration rate) within 24h in a healthy population to help explain future studies using eGFR in the context of a known BV. Blood samples were collected from 30 healthy subjects at six time points within 24h. Serum creatinine (S-Crea) and serum cystatin C (S-Cys-C) were measured, and the BV of eGFR was calculated. Outlier and variance homogeneity analyses were performed, followed by CV-ANOVA on trend-corrected data. The eGFR CVI for the four equations (MDRD, CKD-EPICrea, CKD-EPICys-C, and CKD-EPICrea+Cys-C) were 8.39% (7.50-9.51%), 3.90% (3.49-4.42%), 6.58% (5.88-7.46%), and 5.03% (4.50-5.71%), respectively. The corresponding II and RCVpos/neg values were 0.69, 0.48, 0.51, and 0.31, and (29.30%, - 22.66%), (12.69%, - 11.2 6%), (20.97%, - 17.33%), and (15.88%, - 13.70%), respectively; RCVpos /neg of eGFR was highest in the MDRD equation and lowest in the CKD-EPI Crea equation. Additionally, the RCVpos/neg values of the individual was highest in the MDRD equation and lowest in the CKD-EPICrea+Cys-C equation; they are (56.51%, - 36.11%) and (5.01%, - 4.77%), respectively. We present data on the 24h BV eGFR of the 2021 CKD-EPI equations. The presence of BV has impact on the interpretation of GFR results, affecting CKD disease grading. The RCVpos/neg differences were large among the individuals. When using eGFRs based on the MDRD and CKD-EPI equations, it is necessary to combine RCVpos/neg values before interpreting the results.

The role of inflammatory markers and growth factors in progression of chronic kidney disease in patients with diabetes mellitus

Introduction: A Diabetes mellitus (DM) and chronic kidney disease (CKD) are two chronic non-communicable diseases that have exceeded epidemic thresholds in all countries of the world. The problem of early diagnosis, prevention and treatment of CKD continues to be relevant for modern medicine, and assessment of the severity of CKD and associated cardiovascular complications is of great practical importance for primary and secondary prevention. Objectives: The aim of the study was to assess the role of proinflammatory cytokines, chemokines and growth factors in progression of CKD in patients with DM. Patients and Methods: We screened 155 type 2 DM patients aged 65.00 (55.00-71.00) years. Control group included 21 healthy people with the same age. Renal function was assessed based on the levels of serum creatinine, cystatin C, estimated glomerular filtration rate (eGFR), which was calculated according to the CKD-EPI (chronic kidney disease epidemiology collaboration) equation, and albuminuria, which was assessed as albumin/creatinine ratio (A/C). The analysis of serum and urine biomarkers was carried out by enzyme immunoassay using commercial test systems. Results: Patients with DM had significantly higher levels of proinflammatory cytokines in comparison with the control group. The levels of interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), vascular endothelial growth factor A (VEGF-A), fibroblast growth factor-23 (FGF-23), regulated upon activation, normal T cell expressed and presumably secreted (RANTES), MIG, CRP, kidney injury molecule-1 (KIM-1) and homocysteine gradually increased with decreasing GFR. According to the results of univariate linear regression analysis, there were significant relationships between the levels of VEGF-A, FGF-23, RANTES, tumor necrosis factor alpha (TNF-alpha), MIG, CRP, hs-CRP, IL-6 and renal function. By multiple linear regression analysis adjusted for confounding factors, serum creatinine was significantly correlated with FGF-23 (β=0.40, P&lt;0.001) and Il-6 (β=0.29, P&lt;0.001). Conclusion: Our study demonstrated the important role of growth factors and proinflammatory cytokines in the development and progression of CKD in DM. However, despite these data, the pathogenesis of diabetic changes in the kidneys remains not fully understood and, in order to clarify the possibility of pathogenetic influences on the progression of diabetic nephropathy, it is necessary to study various aspects of its development, including genetic factors.

De-indexed estimated glomerular filtration rates for the dosing of oral antidiabetic drugs in patients with chronic kidney disease.

Introduction: Adjusting drug dose levels based on equations that standardize the estimated glomerular filtration rate (eGFR) to a body surface area (BSA) of 1.73m2 can pose challenges, especially for patients with extremely high or low body mass index (BMI). The objective of the present study of patients with CKD and diabetes was to assess the impact of deindexing creatinine-based equations on estimates of kidney function and on the frequency of inappropriate prescriptions of oral antidiabetic drugs (OADs). Methods: The prospective CKD-REIN cohort is comprised of patients with eGFR <60mL/min/1.73m2. The inclusion criteria for this study were the use of OADs and the availability of data on weight, height and serum creatinine. We compared data for three BMI subgroups (group 1 <30kg/m2; group 2 30-34.9kg/m2; group 3 ≥35kg/m2). Inappropriate prescriptions (contraindicated or over-dosed drugs) were assessed with regard to the summary of product characteristics and the patient's kidney function estimated with the 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, the 2021 CKD-EPI equation, the Modification of Diet in Renal Disease (MDRD) equation, the European Kidney Function Consortium (EKFC) equation, their deindexed estimates, and the Cockcroft-Gault (CG) formula. The impact of deindexing the equations was evaluated by assessing 1) the difference between the indexed and deindexed eGFRs, and 2) the difference in the proportion of patients with at least one inappropriate OAD prescription between the indexed and deindexed estimates. Results: At baseline, 694 patients were receiving OADs. The median BMI was 30.7kg/m2, the mean BSA was 1.98m2, and 90% of patients had a BSA >1.73m2. Deindexing the kidney function estimates led to higher eGFRs, especially in BMI group 3. The proportion of patients with at least one inappropriate prescription differed greatly when comparing indexed and deindexed estimates. The magnitude of the difference increased with the BMI: when comparing BMI group 1 with BMI group 3, the difference was respectively -4% and -10% between deindexed 2021 CKD-EPI and indexed CKD-EPI. Metformin and sitagliptin were the most frequent inappropriately prescribed OADs. Conclusion: We highlight significant differences between the BSA-indexed and deindexed versions of equations used to estimate kidney function, emphasizing the importance of using deindexed estimates to adjust drug dose levels - especially in patients with an extreme BMI.

Assessing the Reliability of Creatinine-Estimated Glomerular Filtration Rate in Living Kidney Donor Candidates: Does it Measure up to the Measured Rate?

Abstract A living donor kidney transplant is the best therapy option for patients with end stage renal disease (ESRD); however, it is associated with an increased risk of ESRD development in the donor. Thorough evaluation of the donor candidate’s kidney function status is essential for the appropriate selection of candidates with minimal risk of post-donation kidney dysfunction. In this study, glomerular filtration rate (GFR) values measured by iohexol plasma clearance (mGFR) and estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-Epi) creatinine equations (eGFR), with and without the race factor (2009 and 2021 CKD-Epi equations, respectively), were compared in a cohort of 303 kidney donor candidates. GFR values were analyzed using Bland-Altman plots, linear regression, Mann-Whitney U tests, and p10 and p30 values. Bland-Altman analysis revealed a lack of agreement between the 2009 and 2021 CKD-Epi eGFR and corresponding mGFR values, with both equations showing a negative bias of 10 – 11 mL/min/1.73m2 and indicating an underestimation of creatinine-eGFR. eGFR underestimation was confirmed by Mann-Whitney U analysis; median GFR values were significantly lower for both CKD-Epi equations as compared to corresponding iohexol-measured values (2009: 85.86; 2021: 87.29; mGFR: 96.58). Despite the overall underestimation, over 14% of donor candidates with eGFR &amp;gt;90 mL/min/1.73m2 had an mGFR value &amp;lt;90 mL/min/1.73m2. Conversely, 36% - 38% of donors with normal kidney function of &amp;gt;90 mL/min/1.73m2 as determined by iohexol-mGFR had corresponding eGFR values &amp;lt;90 mL/min/1.73m2. eGFR showed a significant but poor correlation with mGFR, with R2 values of 0.2775 and 0.2803, respectively. While the 2021 eGFR equation had better accuracy as compared to the 2009 equation (p30 of 81% versus 76%), it displayed low overall accuracy with a p10 of &amp;lt;43%. Separate analysis of Black donor candidates’ eGFR and mGFR values revealed similar trends as observed for the total cohort. While exclusion of the race factor in the 2021 CKD-Epi equation slightly improved accuracy (p30 of 77% versus 72%), the correlation with mGFR remained poor for both equations (R2: 0.1455 and 0.1377 for the 2009 and 2021 equations, respectively). The results of this study confirmed that creatinine-eGFR values, regardless of the race factor, differ significantly from iohexol-mGFR. Our data shows that even potential kidney donors with eGFR &amp;gt;90 mL/min/1.73m2 cannot be presumed to have normal kidney function, while eGFR &amp;lt;90 mL/min/1.73m2 cannot accurately exclude donor candidates. We conclude that creatinine-eGFR cannot reliably serve as a substitute for mGFR in the context of living donor kidney function evaluation.

Cystatin C based estimation of chronic kidney disease and amyotrophic lateral sclerosis in the ALS registry Swabia: associated risk and prognostic value

Kidney function as part of metabolic changes could be associated with amyotrophic lateral-sclerosis (ALS). We investigated the associations between estimated chronic kidney disease (CKD), based on the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) cystatin C equation, and the risk at onset and prognostic value of CKD for ALS. Between October 2010 and June 2014, 362 ALS cases (59.4% men, mean age 65.7 years) and 681 controls (59.5% men, means age 66.3 years) were included in a population-based case–control study based on the ALS registry Swabia in Southern Germany. All ALS cases were followed-up (median 89.7 months), 317 died. Serum samples were measured for cystatin C to estimate the glomerular filtration rate (eGFR) according to the CKD-EPI equation. Information on covariates were assessed by an interview-based standardized questionnaire. Conditional logistic regression models were applied to calculate odds ratios (OR) for risk of ALS associated with eGFR/CKD stages. Time-to-death associated with renal parameters at baseline was assessed in ALS cases only. ALS cases were characterized by lower body mass index, slightly lower smoking prevalence, more intense occupational work and lower education than controls. Median serum cystatin-C based eGFR concentrations were lower in ALS cases than in controls (54.0 vs. 59.5 mL/min pro 1.73 m2). The prevalence of CKD stage ≥ 3 was slightly higher in ALS cases than in controls (14.1 vs. 11.0%). In the adjusted models, CKD stage 2 (OR 1.82, 95% CI 1.32, 2.52) and stage 3 (OR 2.34, 95% CI 1.38, 3.96) were associated with increased ALS risk. In this cohort of ALS cases, eGFR and CKD stage ≥ 3 (HR 0.94; 95% CI 0.64, 1.38) were not associated with prognosis. In this case–control study, higher CKD stages were associated with increased ALS risk, while in the prospective cohort of ALS cases, no indication of an association of CysC-based CKD on mortality was seen. In addition, our work strengthens the importance to evaluate renal function using a marker independent of muscle mass in ALS patients.

Smokeless tobacco consumption and its association with risk factors of chronic kidney disease in rural and peri-urban Bangladesh.

Compared to smoking, which has major consequences in chronic kidney disease (CKD) initiation and progression, smokeless tobacco (SLT) consumption is considered to have fewer health consequences. We investigated the prevalence of SLT consumption and its association with risk factors of CKD in a rural and peri-urban Bangladeshi population. Using random sampling we recruited 872 adults in 2020, from the Mirzapur Demographic Surveillance System of Bangladesh, who had resided in the area for at least five years. Interviews using a semi-structured questionnaire, physical examination and anthropometric measurements were done, followed by blood and urine testing. The blood and urine tests were repeated in selected participants after three months as per the CKD Epidemiology Collaboration equation. The prevalence of SLT consumption was 29%. Being aged ≥46 years (OR=7.10; 95% CI: 4.79-10.94), female (OR=1.64; 95% CI: 1.21-2.22), housewife (OR=1.82; 95% CI: 1.35-2.45), farmer (OR=1.71; 95% CI: 1.06-2.76), widow (OR=3.40; 95% CI: 2.24-5.17), and having no formal schooling (OR=4.91; 95% CI: 3.59-6.72), family income of <$100/month (OR=1.66; 95% CI: 1.13-2.43), sleeping duration <7 hours per day (OR=2.33; 95% CI: 1.70-3.19), were associated with a significantly higher odds of SLT consumption. However, being aged 31-45 years (OR=0.25; 95% CI: 0.16-0.38) had significantly lower odds of being an SLT consumer. Among the diseases investigated, undernutrition (OR=1.63; 95% CI: 1.15-2.33), hypertension (OR=1.52; 95% CI: 1.13-2.05), anemia (OR=1.94; 95% CI: 1.39-2.71) and CKD (OR=1.62; 95% CI: 1.15-2.27) were significantly associated with SLT consumption. In the multivariable analysis, being aged 31-45 years (AOR=3.06; 95% CI: 1.91-4.90), ≥46 years (AOR=15.69; 95% CI: 4.64-53.09) and having no formal schooling (AOR=2.47; 95% CI: 1.72-3.55) were found to have a significant association with being an SLT consumer. SLT consumption is associated with most of the established risk factors of CKD within the studied population.

β-Trace Protein and β2-Microglobulin do not Improve Estimation of Glomerular Filtration Rate in Kidney Transplant Recipients Compared With Creatinine and Cystatin C

Reliable estimates of glomerular filtration rate (eGFR) are important for detecting changes in graft function in kidney transplant recipients. Current eGFR equations are based on plasma creatinine and/or cystatin C; however, these are associated with significant bias. This study investigated if equations based on β-trace protein (BTP) and β2-microglobulin (B2M) performed better than the 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations based on creatinine and cystatin C among kidney transplant recipients. We included samples and data from the clinical trial CONTEXT. Glomerular filtration rate (GFR) was measured by plasma clearance of an exogenous marker. The eGFR was calculated using the CKD-EPI equations for estimating GFR from BTP and/or B2M and the 2021 CKD-EPI creatinine and creatinine-cystatin C equations. The GFR estimates were evaluated 3 (n=82) and 12 (n=64) months after transplant using mean bias, precision, and accuracy. Furthermore, we analyzed the ability of the equations to correctly classify the direction of changes in measured GFR from 3 to 12 months. Among the BTP- and B2M-based equations, the combined eGFR-BTP-B2M performed best with respect to precision (SD=7.64 mL/min/1.73 m2) and accuracy (±10% from measured GFR=36%). The eGFR-BTP-B2M and the eGFR-creatinine-cystatin C (2021) performed similarly when comparing precision, accuracy, and residuals (P=.481). The BTP- and/or B2M-based equations did not perform better than the eGFR-creatinine-cystatin C (2021) in correctly classifying the direction of changes in measured GFR from 3 to 12 months. β-trace protein and/or B2M do not improve the estimation of GFR when compared with creatinine- and cystatin C-based 2021 CKD-EPI equations.

A-091 Assessing the Reliability of Creatinine-Estimated Glomerular Filtration Rate in Living Kidney Donor Candidates: Does it Measure up to the Measured Rate?

Abstract Background A living donor kidney transplant is the best therapy option for patients with end stage renal disease (ESRD); however, it is associated with an increased risk of ESRD development in the donor. Thorough evaluation of the donor candidate’s kidney function status is essential for the appropriate selection of candidates with minimal risk of post-donation kidney dysfunction. Methods Glomerular filtration rate (GFR) values measured by iohexol plasma clearance (mGFR) and estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-Epi) creatinine equations (eGFR), with and without the race factor (2009 and 2021 CKD-Epi equations, respectively), were compared in a cohort of 303 kidney donor candidates. GFR values were analyzed using Bland-Altman plots, linear regression, Mann–Whitney U-tests, and p10 and p30 values. Results Bland-Altman analysis revealed a lack of agreement between the 2009 and 2021 CKD-Epi eGFR and corresponding mGFR values, with both equations showing a negative bias of 10–11 mL/min/1.73 m2 and indicating an underestimation of creatinine-eGFR. eGFR underestimation was confirmed by Mann Whitney U analysis; median GFR values were significantly lower for both CKD-Epi equations as compared to corresponding iohexol-measured values (2009: 85.86; 2021: 87.29; mGFR: 96.58). Despite the overall underestimation, over 14% of donor candidates with eGFR &amp;gt;90 mL/min/1.73 m2 had an mGFR value &amp;lt;90 mL/min/1.73 m2. Conversely, 36%–38% of donors with normal kidney function of &amp;gt;90 mL/min/1.73 m2 as determined by iohexol-mGFR had corresponding eGFR values &amp;lt;90 mL/min/1.73 m2. eGFR showed a significant but poor correlation with mGFR, with R2 values of 0.2775 and 0.2803, respectively. While the 2021 eGFR equation had better accuracy as compared to the 2009 equation (p30 of 81% vs 76%), it displayed low overall accuracy with a p10 of &amp;lt;43%. Separate analysis of Black donor candidates’ eGFR and mGFR values revealed similar trends as observed for the total cohort. While exclusion of the race factor in the 2021 CKD-Epi equation slightly improved accuracy (p30 of 77% vs 72%), the correlation with mGFR remained poor for both equations (R2: 0.1455 and 0.1377 for the 2009 and 2021 equations, respectively). Conclusion The results of this study confirmed that creatinine-eGFR values, regardless of the race factor, differ significantly from iohexol-mGFR. Our data shows that even potential kidney donors with eGFR &amp;gt;90 mL/min/1.73 m2 cannot be presumed to have normal kidney function, while eGFR &amp;lt;90 mL/min/1.73 m2 cannot accurately exclude donor candidates. We conclude that creatinine-eGFR cannot reliably serve as a substitute for mGFR in the context of living donor kidney function evaluation.

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.

Abstract P374: Greater Burden Of Chronic Kidney Disease Is Associated With Hypertension Prevalence And Management In South Africa

Introduction: Complications e.g., chronic kidney disease (CKD) are frequent with longstanding hypertension, particularly if poorly managed. Hypothesis: We assessed the hypothesis that prevalence and associations of CKD differed by hypertension prevalence, awareness, treatment and control in South Africa using five CKD estimates. Methods: In this randomly selected cross-sectional study, glomerular filtration rate (GFR) was estimated by CKD Epidemiology Collaboration (CKD-EPI) equations [CKD-EPI creatinine (CKD-EPIcr), CKD-EPI cystatin C, CKD-EPI creatinine-cystatin C], Modification of Diet in Renal Disease (MDRD) and Cockcroft-Gault formula (CGF). Blood pressures were measured, and history of hypertension management collected. Results: Among 1092 participants, mean age 43.5 years, 64% women, the prevalence of hypertension was 42% with similar rates in men (41%) and women (43%). In participants with hypertension (n=460), awareness, treatment and control were 61.5% (283/460), 47.2% (217/460) and 27.0% (124/460), with better rates in women compared with men (p&lt;0.001). CKD prevalence (GFR&lt;60 mL/min/1.73m 2 ) was 2.0-5.9% overall using 5 formulae, and significantly higher in participants with (3.9-10.2%) compared to without hypertension (0.6-2.7%) (p&lt;0.001). In participants with hypertension, CKD was higher in those aware (5.7-13.8%) vs unaware (1.1-4.5%) of their diagnosis (p≤0.015), on treatment (6.9-14.3%) vs none (1.2-6.6%) (p≤0.016), and those with controlled (BP&lt;140/90 mmHg) vs uncontrolled hypertension (6.5-15.1% vs. 3-8%, p≤0.096). In models adjusted for age, sex and obesity, higher hypertension prevalence and awareness were significantly (p&lt;0.05) associated with CKD by CKD-EPIcr and MDRD equations; hypertension treatment was significantly associated with CKD by CKD-EPIcr, MDRD and CGF formulae, while hypertension control was not associated with CKD. Conclusions: This study highlights the higher prevalence and greater likelihood of CKD in participants with hypertension and those who were diagnosed and receiving treatment, likely due to the longer duration of their hypertension compared with their counterparts. Higher CKD in the diagnosed and treated reinforces the need for optimal control, which was low in this cohort.

Discordance Between Creatinine-Based and Cystatin C–Based Estimated GFR: Interpretation According to Performance Compared to Measured GFR

Use of cystatin C in addition to creatinine to estimate glomerular filtration rate (estimated glomerular filtration rate based on cystatin C [eGFRcys] and estimated glomerular filtration rate based on creatinine [eGFRcr], respectively) is increasing. When eGFRcr and eGFRcys are discordant, it is not known which is more accurate, leading to uncertainty in clinical decision making. Cross-sectional analysis. Four thousand fifty participants with measured glomerular filtration rate (mGFR) from 12 studies in North America and Europe. Serum creatinine and serum cystatin C. Performance of creatinine-based and cystatin C-based glomerular filtration rate estimating equations compared to mGFR. We evaluated the accuracy of eGFRcr, eGFRcys, and the combination (eGFRcr-cys) compared to mGFR according to the magnitude of the difference between eGFRcr and eGFRcys (eGFRdiff). We used CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equations to estimate glomerular filtration rate. eGFRdiff was defined as eGFRcys minus eGFRcr and categorized as less than-15,-15 to<15, and≥15 mL/min/1.73 m2 (negative, concordant, and positive groups, respectively). We compared bias (median of mGFR minus eGFR) and the percentage of eGFR within 30% of mGFR. Thirty percent of participants had discordant eGFRdiff (21.0% and 9.6% negative and positive eGFRdiffs, respectively). In the concordant eGFRdiff group, all equations displayed similar accuracy. In the negative eGFRdiff groups, eGFRcr had a large overestimation of mGFR (-13.4 [-14.5 to-12.2] mL/min/1.73 m2) and eGFRcys had a large underestimation (9.9 [9.1-11.2] mL/min/1.73m2), with opposite results in the positive eGFRdiff group. In both negative and positive eGFRdiff groups, eGFRcr-cys was more accurate than either eGFRcr or eGFRcys. These results were largely consistent across age, sex, race, and body mass index. Few participants with major comorbid conditions. Discordant eGFRcr and eGFRcys are common. eGFR using the combination of creatinine and cystatin C provides the most accurate estimates among persons with discordant eGFRcr or eGFRcys.

Prevalence and risk factors for impaired renal function among Asian patients with nonalcoholic fatty liver disease

BackgroundNonalcoholic fatty liver disease (NAFLD) is associated with impaired renal function, and both diseases often occur alongside other metabolic disorders. However, the prevalence and risk factors for impaired renal function in patients with NAFLD remain unclear. The objective of this study was to identify the prevalence and risk factors for renal impairment in NAFLD patients. MethodsAll adults aged 18–70 years with ultrasound-diagnosed NAFLD and transient elastography examination from eight Asian centers were enrolled in this prospective study. Liver fibrosis and cirrhosis were assessed by FibroScan-aspartate aminotransferase (FAST), Agile 3+ and Agile 4 scores. Impaired renal function and chronic kidney disease (CKD) were defined by an estimated glomerular filtration rate (eGFR) with value of < 90 mL/min/1.73 m2 and < 60 mL/min/1.73 m2, respectively, as estimated by the CKD-Epidemiology Collaboration (CKD-EPI) equation. ResultsAmong 529 included NAFLD patients, the prevalence rates of impaired renal function and CKD were 37.4% and 4.9%, respectively. In multivariate analysis, a moderate-high risk of advanced liver fibrosis and cirrhosis according to Agile 3+ and Agile 4 scores were independent risk factors for CKD (P< 0.05). Furthermore, increased fasting plasma glucose (FPG) and blood pressure were significantly associated with impaired renal function after controlling for the other components of metabolic syndrome (P< 0.05). Compared with patients with normoglycemia, those with prediabetes [FPG ≥ 5.6 mmol/L or hemoglobin A1c (HbA1c) ≥ 5.7%] were more likely to have impaired renal function (P< 0.05). ConclusionsAgile 3+ and Agile 4 are reliable for identifying NAFLD patients with high risk of CKD. Early glycemic control in the prediabetic stage might have a potential renoprotective role in these patients.

Comparison of the performance of currently used estimated glomerular filtration rate equations with 24-hour urine creatinine clearance: sample analysis of randomised controlled trial participants

ObjectiveThere are several equations for estimating the glomerular filtration rate (GFR), and each method has its limitations. We compared various estimated GFR (eGFR) equations with 24 hours urine creatinine clearance...

Baseline renal function and the risk of cancer among apparently healthy middle-aged adults

BackgroundThe association between mildly impaired renal function with all-site and site-specific cancer risk is not established. We aim to explore this association among apparently healthy adults. MethodsWe followed 25,073 men and women, aged 40–79 years, free of cancer or cardiovascular disease at baseline who were screened annually in preventive healthcare settings. The estimated glomerular filtration rate (eGFR) was calculated using the CKD Epidemiology Collaboration equation (CKD-EPI) and classified into four mutually exclusive groups: <60, 60–74, 75–89, ≥90 (mL/min/1.73 m²). The primary outcome was all-site cancer while the secondary outcome was site-specific cancer. Cancer data was available from a national registry. ResultsMean age at baseline was 50 ± 8 years and 7973 (32 %) were women. During a median follow-up of 9 years (IQR 3–16) and 256,279 person years, 2045 (8.2 %) participants were diagnosed with cancer. Multivariable Cox model showed a 1.2 (95 %CI: 1.0–1.4 p = 0.05), 1.2 (95 %CI: 1.0–1.4 p = 0.02), and 1.4 (95 %CI: 1.1–1.7 p = 0.003) higher risk for cancer with eGFR of 75–89, 60–74, and < 60, respectively. Site-specific analysis demonstrated a 1.8 (95 %CI: 1.2–2.6 p = 0.004), 1.7 (95 %CI: 1.2–2.6 p = 0.004) and 2.2 (95 %CI: 1.3–3.6 p = 0.002) increased risk for prostate cancer with eGFR of 75–89, 60–74, and < 60, respectively. eGFR< 60 was associated with a 2.0 (95 %CI: 1.1–3.7 p = 0.03) and 3.7 (95 %CI: 1.1–13.1 p = 0.04) greater risk for melanoma and gynecological caner respectively. ConclusionsCKD stage 2 and worse is independently associated with higher risk for cancer incidence, primarily prostate cancer. Early intervention and screening are warranted among these individuals in order to reduce cancer burden.

Mild renal impairment is associated with increased cardiovascular events and all-cause mortality following cancer diagnosis.

The association between mildly decreased renal function and cardiovascular (CV) outcomes in cancer patients remains unestablished. We sought to explore this association in asymptomatic self-referred healthy adults. We followed 25, 274 adults, aged 40-79 years, who were screened in preventive healthcare settings. Participants were free of CV disease or cancer at baseline. The estimated glomerular filtration rate (eGFR) was calculated according to the CKD Epidemiology Collaboration equation and categorized into groups [≤59, 60-69, 70-79, 80-89, 90-99, ≥100 (ml/min/1.73 m²)]. The outcome included a composite of death, acute coronary syndrome, or stroke, examined using a Cox model with cancer as a time-dependent variable. Mean age at baseline was 50 ± 8 years and 7973 (32%) were women. During a median follow-up of 6 years (interquartile range: 3-11), 1879 (7.4%) participants were diagnosed with cancer, of them 504 (27%) develop the composite outcome and 82 (4%) presented with CV events. Multivariable time-dependent analysis showed an increased risk of 1.6, 1.4, and 1.8 for the composite outcome among individuals with eGFR of 90-99 [95% confidence interval (CI): 1.2-2.1 P = 0.01], 80-89 (95% CI: 1.1-1.9, P = 0.01) and 70-79 (95% CI: 1.4-2.3, P < 0.001), respectively. The association between eGFR and the composite outcome was modified by cancer with 2.7-2.9 greater risk among cancer patients with eGFR of 90-99 and 80-89 but not among individuals free from cancer ( Pinteraction < 0.001). Patients with mild renal impairment are at high risk for CV events and all-cause mortality following cancer diagnosis. eGFR evaluation should be considered in the CV risk assessment of cancer patients.

Validation of the European Kidney Function Consortium Equation in Chinese Adult Population: An Equation Standing on the Shoulders of Predecessors

Background: Equations based on serum creatinine (SCr) have been extensively applied to estimate glomerular filtration rate (GFR), but their performance is debatable. In 2021, the European Kidney Function Consortium (EKFC) published one novel SCr-based formula, which combined the feature of Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and full age spectrum (FAS) equations, but its potential applications remain unknown. We seek to assess the appropriateness of the three equations in Chinese adults. Methods: A total of 3,692 participants (median age, 54 years) were included. Reference GFR (rGFR) was measured by the 99mTc-DTPA renal dynamic imaging method. Estimated GFR (eGFR) was calculated by the CKD-EPI, FAS, and EKFC equations. Correlation coefficients and Bland-Altman analysis were adopted to evaluate their validity. The performance was assessed in subgroups according to age, sex, rGFR, and SCr, considering the bias, accuracy, and precision. Results: The average rGFR was 74.2 mL/min/1.73 m². eGFR by EKFC showed a relatively stronger correlation with rGFR (R = 0.749) and a larger area under the receiver operating characteristic curve (0.902). EKFC was significantly less biased and exhibited the highest P30 in the entire population (bias = 3.61, P30 = 73.3%). It also performed well in all analyzed subgroups, especially in participants with normal or slightly impaired renal function (rGFR≥60 mL/min/1.73 m²), and low SCr. Conclusions: Compared to the other two SCr-based formulas, EKFC performed better in the Chinese. Thus, it might serve as a good alternative, until a more suitable formula is developed for the Chinese population.

#3503 IMPACT OF ADOPTING THE NEW CKD-EPI 2021 EQUATION ON EGFR AND CKD DETECTION IN A MULTI-ETHNIC DUTCH POPULATION: THE HELIUS STUDY

Abstract Background and Aims The 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation is the current standard method for estimating GFR. There has been debate whether or not to exclude the race/ethnicity coefficient from this equation. Recently, the National Kidney Foundation and American Society of Nephrology Task Force on Reassessing Race in Diagnosing Kidney Disease recommended a new 2021 CKD-EPI race-free creatinine-based equation. The impact of this equation has not thoroughly been evaluated in the European population. We explored the impact of adopting this formula on both eGFR and estimates of CKD prevalence in a multi-ethnic Dutch population. Method We cross-sectionally analysed baseline data of 21,617 participants (mean age 44yr, 42% male) of the multi-ethnic HELIUS cohort study (Amsterdam, the Netherlands). Three groups were distinguished: participants of African Surinamese (4,151), Ghanaian (2,339) and other, non-African (15,127) background. eGFR was calculated using the 2009 and 2021 CKD-EPI equation. Multiple regression analyses were performed to determine differences in eGFR with additional adjustments for age, sex and traditional cardiovascular and renal risk factors. CKD prevalence (i.e., eGFR (&amp;lt;60mL/min/1.73m2) and/or ACR (≥3mg/mmol) was calculated. In each ethnic group three approaches to improve CKD case detection for both equations were compared by targeting participants with traditional renal risk factors (i.e., diabetes mellitus, hypertension or cardiovascular disease), by subsequently adding an age criterium (&amp;gt;40, &amp;gt;50, or &amp;gt;60 yrs), and low socio-economic status (none or elementary schooling). For each approach, c-statistics for CKD probability were compared. Results Differences between groups varied according to the equation used. Compared to participants with non-African backgrounds (mean eGFR 102 mL/min/1.73m2), age- and sex-adjusted differences (p&amp;lt;0.001) in the mean eGFR (SE) were 4.6±0.2 and -8.9±0.2 mL/min/1.73m2,in participants with African Surinamese, and 3.2±0.3 and -10.4±0.3 mL/min/1.73m2 in participants with Ghanaian background for the 2009 and 2021 CKD-EPI equations, respectively. Further adjustments did not change this. However, CKD prevalences were similar for both equations: 10.6% vs 10.8% (p = 0.30) in the whole cohort, 10.9 vs. 11.6% (p = 0.33) among African Surinamese and 12.0 vs 12.6% (p = 0.21) among Ghanaians. CKD case detection did not differ between the screening approaches nor between both equations. Also, c-statistics for CKD probabilities were not influenced by either equation. Conclusion In our cohort, adoption of the 2021 CKD-EPI equation leads to lower eGFR in participants of African Surinamese and Ghanaian background. However, only small not statistically significant differences in CKD prevalences, overall and in high-risk groups, were found. Our study indicates that discontinuation of the race-coefficient may have little impact on CKD detection in a multi-ethnic Dutch population.