Evaluation of the CKD-EPI 2021 creatinine equation using laboratory data: Considerations for practice changes among clinical laboratories in British Columbia, Canada.

INTRODUCTION: Clinical laboratories in British Columbia, Canada implemented the CKD-EPI 2009 equation without the race variable for estimated glomerular filtration rate (eGFR) reporting since 2014. As more clinical laboratories adopt the new CKD-EPI 2021 equation, the study aims to compare these two race-free CKD-EPI eGFR equations using the laboratory data from a large tertiary hospital in BC and evaluate the impact on reclassification of eGFR category. METHODS: Serum/plasma creatinine results and demographic data were collected from Vancouver General Hospital laboratory. The CKD-EPI 2009 without the race variable and CKD-EPI 2021 equations were computed. eGFR and its distributions were compared and reclassification of eGFR category was assessed across the full cohort and in specific patient populations. RESULTS: The analysis included 58,763 patients. The median age was 57 years, with women comprising 51 % of the population. The median of eGFR changed from 85 to 90 mL/min/1.73 m2 using the CKD-EPI 2009 equation without the race variable and the CKD-EPI 2021 equation, respectively. The CKD-EPI 2021 equation reclassified 11.86 % of patients, mainly from G3a (45-59 mL/min/1.73 m2) to G2 (60-89 mL/min/1.73 m2). There was statistical significance between the non-renal and the renal population reclassified from G5 (<15 mL/min/1.73 m2) to G4 (15-29 mL/min/1.73 m2). CONCLUSIONS: Using laboratory data representative of local populations, we observed an overall positive shift to higher eGFR, with 11.86 % of individuals having improved eGFR categories based on the CKD-EPI 2021 equation. This study provides insights into clinical implications at both the individual and population levels. The data-based approach is the first step towards adopting the CKD-EPI 2021 equation within the province.

Performance of the race-free CKD-EPI creatinine-based eGFR equation in a Danish cohort with measured GFR.

Background: In 2021, an updated Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation for estimated glomerular filtration rate (eGFR) without a coefficient for race (CKD-EPI21) was developed. The performance of this new equation has yet to be examined among specific patient groups. Methods: We compared the performances of the new CKD-EPI21 equation and the 2009 equation assuming non-Black race (CKD-EPI09-NB) in patients with GFR measured by chromium-51-EDTA plasma clearance at Aarhus University Hospital in Denmark during 2010-18. We examined bias, accuracy, precision and correct classification of chronic kidney disease (CKD) stage using chromium-51-EDTA clearance as the reference standard. We assessed the performance in the total cohort, cancer patients and potential living kidney donors. We also assessed the performance stratified by CKD stage in the total cohort. Results: In this predominantly white population, the CKD-EPI21 equation performed slightly better than the CKD-EPI09-NB equation in both the total cohort (N = 4668), and in cancer patients (N = 3313) and potential living kidney donors (N = 239). In the total cohort, the CKD-EPI21 equation demonstrated a slightly lower median absolute bias (-0.2 versus -4.4 mL/min/1.73 m2), and a similar accuracy, precision and correct classification of CKD stage compared with the CKD-EPI09-NB equation. When stratified by CKD stage, the CKD-EPI09-NB equation performed slightly better than the CKD-EPI21 equation among patients with a measured GFR (mGFR) <60 mL/min/1.73 m2. Conclusions: In a selected cohort of Danish patients with mGFR, the CKD-EPI21 equation performed slightly better than the CKD-EPI09-NB equation except for patients with a mGFR <60 mL/min/1.73 m2, where CKD-EPI09-NB performed slightly better although the differences were considered clinically insignificant.

Average creatinine-urea clearance: revival of an old analytical technique?

Background: Creatinine-based equations such as the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) are recommended for estimating glomerular filtration rate (eGFR) in clinical practice, but have reduced performance in advanced stages of chronic kidney disease. However, only rarely studies have evaluated the performance of eGFR by measuring the average of the urinary clearances of creatinine and urea (mClUN-cr) compared with the eGFR equations. Methods: This cross-sectional study evaluated the usefulness of mClUN-cr in a population of 855 participants who performed a GFR measurement by urinary inulin clearance. The performance of mClUN-cr was compared with those of CKD-EPI 2009 and CKD-EPI 2021, considering three criteria: bias, precision and accuracy. Results: In the whole sample, the mClUN-cr performed similarly to CKD-EPI equations (2009 and 2021) [precision: 11.5 (95% CI 10.5; 12.5) vs 19.0 (95% CI 17.2; 20.1) and 19.1 (95% CI 17.4; 20.4), and accuracy P30: 97.0 (95% CI 95.8; 98.0) vs 82.0 (95% CI 79.2; 84.4) and 77.2 (95% CI 74.5; 80.0)]. The CKD-EPI equations (2009 and 2021) had the best performance when mGFR was >60 mL/min/1.73 m2. In contrast, the mClUN-cr performed better than others with lowest mGFR values, more noticeable when mGFR was <60 mL/min/1.73 m2. Conclusions: The study described the best performance of mClUN-cr at GFR levels below 60 mL/min/1.73 m2 and a satisfactory result in the overall cohort. The findings point to a role of this tool, especially for estimating GFR in chronic kidney disease patients in developing countries, when reference measurement of GFR is not available.

Optimal Glomerular Filtration Rate Equations for Various Age Groups, Disease Conditions and Ethnicities in Asia: A Systematic Review.

(1) Background: The performance of estimated glomerular filtration rate (eGFR) equations in the Asian population has been widely questioned. The primary objective of this study was to gather evidence regarding optimal GFR equations in Asia for various age groups, disease conditions, and ethnicities. The secondary objective was to see whether the equations based on the combination of creatinine and cystatin C biomarkers if employed are satisfactory across different age groups and disease conditions in various ethnicities in Asia compared to those based on either of the single biomarkers. (2) Methods: Validation studies that had both creatinine and cystatin C-based equations either alone or in combination, validated in specific disease conditions, and those which compared the performance of these equations with exogenous markers were eligible only. The bias, precision, and 30% accuracy (P30) of each equation were recorded accordingly. (3) Results: Twenty-one studies consisting of 11,371 participants were included and 54 equations were extracted. The bias, precision, and P30 accuracies of the equations ranged from -14.54 to 9.96 mL/min/1.73 m2, 1.61 to 59.85 mL/min/1.73 m2, and 4.7% to 96.10%. The highest values of P30 accuracies were found for the JSN-CKDI equation (96.10%) in Chinese adult renal transplant recipients, for the BIS-2 equation (94.5%) in Chinese elderly CKD patients, and Filler equation (93.70%) also in Chinese adult renal transplant recipients. (4) Conclusions: Optimal equations were identified accordingly and it was proven that combination biomarker equations are more precise and accurate in most of the age groups and disease conditions. These can be considered equations of choice for the specific age groups, disease conditions, and ethnicities within Asia.

¿Es apropiada la aplicación de la nueva ecuación Chronic Kidney Disease Epidemiology Consortium (CKD-EPI 2021) en la población española? / Is the use of the new Chronic Kidney Disease Epidemiology Consortium (CKD-EPI 2021) formula appropriate for the Spanish population?

Introducción Las sociedades estadounidenses de nefrología recomiendan cambiar la ecuación CKD-EPI 2009 por la nueva CKD-EPI 2021, que no incluye el coeficiente de raza, para estimar la tasa de filtrado glomerular (TFGe). Se desconoce cómo podría afectar este cambio a la distribución de la enfermedad renal de la población española predominantemente caucásica. Métodos Se estudiaron dos cohortes de adultos de la provincia de Cádiz, BD-SIDICA (n=264.217 personas) y BD-PANDEMIA (n=64.217), que disponían de mediciones de creatinina plasmática entre 2017 y 2021. Se calcularon los cambios de la TFGe y la consecuente reclasificación en las diferentes categorías de la clasificación KDIGO-2012 al modificar la ecuación CKD-EPI 2009 por la de 2021. Resultados En comparación con la ecuación de 2009, CKD-EPI-21 arrojó una TFGe más alta, con una mediana de 3,8mL/min/1,73m2 (IQR: 2,98-4,48) en BD-SIDICA y de 3,89mL/min/1,73m2 (IQR: 3,05-4,55) en BD-PANDEMIA. Como primera consecuencia, del total de la población, el 15,3% en BD-SIDICA y el 15,1% en BD-PANDEMIA y el 28,1% y el 27,3%, respectivamente, de la población con enfermedad renal (G3-G5), se reclasificó a una categoría de TFGe más alta y ningún sujeto a una más grave. Como segunda consecuencia, la prevalencia de la enfermedad renal disminuyó del 9% al 7,5% en ambas cohortes. Conclusiones Implementar la ecuación CKD-EPI-21 en la población española, predominantemente caucásica, aumentaría la TFGe en una cantidad modesta (mayor en hombres y con mayor edad o TFG) y una proporción importante de la población se clasificaría en una categoría de TFGe superior, con la consiguiente disminución de la prevalencia de la enfermedad renal (AU)

Introduction United States nephrology societies recommend changing from the CKD-EPI 2009 equation to the new CKD-EPI 2021 equation, which does not include the race coefficient, for calculating estimated glomerular filtration rate (eGFR). It is unknown how this change might affect the distribution of kidney disease in the predominantly Caucasian Spanish population. Methods Two databases of adults from the province of Cádiz, DB-SIDICA (n=264,217) and BD-PANDEMIC (n=64,217), that had plasma creatinine measurements recorded between 2017 and 2021 were studied. Changes in eGFR and the consequent reclassification into different categories of the KDIGO2012 classification resulting from substituting the CKD-EPI 2009 equation for the 2021 equation were calculated. Results Compared to the 2009 equation, CKD-EPI 2021 yielded a higher eGFR, with a median of 3.8mL/min/1.73m2 (IQR: 2.98-4.48) in DB-SIDICA and 3.89mL/min/1.73m2 (IQR: 3.05-4.55) in DB-PANDEMIA. The first consequence was that 15.3% of the total population in DB-SIDICA and 15.1% of the total population in DB-PANDEMIA were reclassified into a higher category of eGFR, as were 28.1% and 27.3%, respectively, of the population with CKD (G3-G5); no subjects were classified into the more severe category. The second consequence was that the prevalence of kidney disease decreased from 9% to 7.5% in both cohorts. Conclusions Implementing the CKD-EPI 2021 equation in the Spanish population, which is predominantly Caucasian, would increase eGFR by a modest amount (greater in men and those who are older or have a higher GFR). A significant proportion of the population would be classified into a higher eGFR category, with a consequent decrease in the prevalence of kidney disease (AU)

Is the use of the new Chronic Kidney Disease Epidemiology Consortium (CKD-EPI 2021) formula appropriate for the Spanish population?

INTRODUCTION: United States nephrology societies recommend changing from the CKD-EPI 2009 equation to the new CKD-EPI 2021 equation, which does not include the race coefficient, for calculating estimated glomerular filtration rate (eGFR). It is unknown how this change might affect the distribution of kidney disease in the predominantly Caucasian Spanish population. METHODS: Two databases of adults from the province of Cádiz, DB-SIDICA (N=264,217) and DB-PANDEMIA (N=64,217), that had plasma creatinine measurements recorded between 2017 and 2021 were studied. Changes in eGFR and the consequent reclassification into different categories of the KDIGO 2012 classification resulting from substituting the CKD-EPI 2009 equation for the 2021 equation were calculated. RESULTS: Compared to the 2009 equation, CKD-EPI 2021 yielded a higher eGFR, with a median of 3.8mL/min/1.73m2 (IQR 2.98-4.48) in DB-SIDICA and 3.89mL/min/1.73m2 (IQR 3.05-4.55) in DB-PANDEMIA. The first consequence was that 15.3% of the total population in DB-SIDICA and 15.1% of the total population in DB-PANDEMIA were reclassified into a higher category of eGFR, as were 28.1% and 27.3%, respectively, of the population with CKD (G3-G5); no subjects were classified into the more severe category. The second consequence was that the prevalence of kidney disease decreased from 9% to 7.5% in both cohorts. CONCLUSIONS: Implementing the CKD-EPI 2021 equation in the Spanish population, which is predominantly Caucasian, would increase eGFR by a modest amount (greater in men and those who are older or have a higher GFR). A significant proportion of the population would be classified into a higher eGFR category, with a consequent decrease in the prevalence of kidney disease.

Validation of the EKFC equation for glomerular filtration rate estimation and comparison with the Asian-modified CKD-EPI equation in Chinese chronic kidney disease patients in an external study.

OBJECTIVES: The aim of this study is to determine whether new European Kidney Function Consortium (EKFC) equation is more applicable than Asian-modified CKD-EPI equation in clinical practice, having a higher accuracy in estimating GFR in our external CKD population. METHODS: We calculated estimated GFREKFC and GFRCKD-EPI independently using the EKFC and Asian-modified CKD-EPI formulas, respectively. The clinical diagnostic performance of the two equations was assessed and compared by median bias, precision, accuracy (P30) and so on, using 99mTc-DTPA dual plasma sample clearance method as a reference method for GFR measurement (mGFR). The equation that met the following targets was superior: (1) median bias within ± 3 mL/min/1.73 m2; (2) P30 > 75%; and (3) better precision and 95% limits of agreement in Bland-Altman analysis. RESULTS: Totally, 160 CKD patients were recruited in our external cohort. GFREKFC was highly related to mGFR, with a regression equation of GFREKFC=mGFR × 0.87 + 5.27. Compared with the Asian-modified CKD-EPI equation, EKFC equation demonstrated a wider median bias (-1.64 vs. 0.84 mL/min/1.73 m2, p < 0.01) that was within 3 mL/min/1.73 m2 and not clinically meaningful. Furthermore, the precision (12.69 vs. 12.72 mL/min/1.73 m2, p = 0.42), 95% limits of agreement in Bland-Altman analysis (42.4 vs. 44.4 mL/min/1.73 m2) and incorrect reclassification index of the two target equations were almost identical. Although, EKFC equation had a slightly better P30 (80.0% vs. 74.4%, p = 0.01). CONCLUSIONS: The overall performance of EKFC equation is acceptable. There is no clinically meaningful difference in the performance of the Asian-modified CKD-EPI and EKFC equations within the limits imposed by the small sample size.

Comparison of the profiles of patients defined by age-adapted and fixed threshold CKD criteria: a nationwide, cross-sectional study.

Background: Kidney function declines naturally with advancing age. Therefore an age-adapted estimated glomerular filtration rate (eGFR) threshold has been proposed instead of the fixed threshold for CKD definition. This study aims to describe and compare the profile of CKD patients defined by these two criteria in a Chinese population. Method: We recruited adult participants with selected biochemical tests from the Chinese Physiological Constant and Health Condition survey conducted from 2007 to 2011, with the GFR estimated by the Chronic Kidney Disease Epidemiology Collaboration formula. The age-adapted threshold of eGFR is 75, 60 and 45 ml/min/1.73 m2 for the population <40 years of age, 40-64 years and >64 years, respectively. The fixed threshold is 60 ml/min/1.73 m2 for all ages. Results: Among the recruited 23 438 participants, 480 were diagnosed with CKD by fixed threshold criteria, while 391 were diagnosed with CKD by age-adapted criteria. Patients diagnosed by fixed threshold criteria were significantly older (66.4 versus 43.4 years; P < .001) and had a higher prevalence of all CVD risk factors compared with the non-CKD population. In contrast, age-adapted criteria defined a younger patient group and were not significantly associated with diabetes or obesity. When adjusted by age and gender, fixed threshold-defined CKD was not significantly associated with the number of coexisting CVD risk factors, while age-adapted-defined CKD was significantly associated. We also found that the CKD patients defined by age-adapted criteria matched well with the 2.5th percentile of eGFR in Chinese individuals. When compared with their age- and gender-matched controls, patients included by age-adapted criteria but excluded by fixed threshold criteria had a significantly higher prevalence of hypertension (23.2% versus 7.7%; P < .001) and hyperuricaemia (25.0% versus 5.5%; P < .001), while patients included only by the fixed threshold criteria were not significantly different in the prevalence of CVD risk factors and CKD-related disturbance except for hyperuricaemia (41.2% versus 14.0%; P < .001). Conclusion: An age-adapted criterion is more closely associated with CVD risk factors and CKD-related diseases compared with fixed threshold criteria.

Kidney disease burden in an Asian Indian population: Effect of the new 2021 serum creatinine CKD-EPI equation.

AIMS: CKD-EPI (chronic kidney disease-epidemiological) serum creatinine equation is widely accepted for calculating estimated glomerular filtration rate (eGFR). The effect of transitioning from the older 2009 to the newer race-independent 2021 CKD-EPI equation on the estimated kidney disease burden (eKDB) was studied in an Asian-Indian population. METHODS: The study included 1156 adults, the two equations were compared for agreement (Bland-Altman and Cohen's kappa) and concordance (Lin's correlation and test for proportions). RESULTS: The 2021 CKD-EPI increased the eGFR (positive-bias), independent of age-group, gender or presence of type 2 diabetes mellitus (T2DM) and hypertension (HTN). Thus, the eKDB was significantly decreased by 2021 CKD-EPI equation. The agreement was highest for the age-group 31-40 years (95.8 % versus 87.5 % for > 50 years). Besides, the eGFR category was shifted from G3 to G1 in 8.2 % (95 % CI: 6.8-9.9) individuals by 2021 CKD-EPI. The effect of transition on eKDB was greater in individuals > 50 years (7.4 %) or with HTN (6.3 %). CONCLUSION: In comparison to the old equation, the 2021 CKD-EPI equation increased the eGFR, lowering the eKDB in this Asian-Indian cohort. The degree of lowering was affected by age-group, and presence of T2DM /HTN, but independent of gender.

The Xiangya equation could not replace the Asian modified CKD-EPI equation in estimating glomerular filtration rate in Chinese patients with chronic kidney disease.

BACKGROUND: To evaluate the clinical practicability of the Xiangya equation in estimating glomerular filtration rate (GFR) and compare with the Asian modified Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation, assessing whether the Xiangya equation could replace the Asian modified CKD-EPI equation as the preferred method for predicting GFR in the Chinese CKD patients in an external validation study. METHODS: The GFR was determined simultaneously by two methods: (a) the Asian modified CKD-EPI equation (GFRCKD-EPI); (b) the Xiangya equation (GFRXiangya); diagnostic performance of the two models was compared by the regression analysis, the Bland-Altman plot, bias, precision and P30 under the background of 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) dual plasma sample clearance method as reference method for GFR measurement (mGFR). RESULTS: A total of 158 Chinese CKD patients were included in our external study. The GFRXiangya was highly related with mGFR, with the correlation coefficient of 0.92. The regression equation was GFRXiangya = 0.55*mGFR + 28.25, where the regression coefficient was far away from one and the intercept was wide. Compared with the Asian modified CKD-EPI equation, the performance of the Xiangya equation demonstrated a poorer bias (9.5 vs - 3.3 ml/min/1.73 m2, P < 0.001), an inferior precision (23.9 vs 13.0 ml/min/1.73 m2, P < 0.001), a lower P30 (51.3% vs 73.4%, P < 0.001) and a wider 95% limit of agreement in Bland-Altman analysis (65.0 vs 44.9 ml/min/1.73 m2). CONCLUSION: Due to relatively inferior performance, the Xiangya equation could not replace the Asian modified CKD-EPI equation in estimating GFR in Chinese patients with chronic kidney disease in our external cohort.

The effect of race coefficients on preemptive listing for kidney transplantation.

Background: Race coefficients of estimated glomerular filtration rate (eGFR) formulas may be partially responsible for racial inequality in preemptive listing for kidney transplantation. Methods: We used the Scientific Registry of Transplant Recipients database to evaluate differences in racial distribution of preemptive listing before and after application of the Modification of Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) race coefficients to all preemptively listed non-Black kidney transplant candidates (eGFR modulation). Odds of preemptive listing were calculated by race, with Black as the reference before and after eGFR modulation. Variables known to influence preemptive listing were included in the model. Results: Among 385 087 kidney-alone transplant candidates from 1 January 2010 to 2 December 2020, 118 329 (30.7%) candidates were identified as preemptively listed (71.7% White, 19% Black, 7.8% Asian, 0.6% multi-racial, 0.6% Native American and 0.3% Pacific Islander). After eGFR modulation, non-Black patients with an eGFR ≥20 mL/min/1.73 m2 were removed. Compared with Black candidates, the adjusted odds of preemptive listing for White candidates decreased from 2.01 [95% confidence interval (95% CI) 1.78-2.26] before eGFR modulation to 1.18 (95% CI 1.0-1.39; P = 0.046) with the MDRD and 1.37 (95% CI 1.18-1.58) with the CKD-EPI equations after adjusting for race coefficients. Conclusions: Removing race coefficients in GFR estimation formulas may result in a more equitable distribution of Black candidates listed earlier on a preemptive basis.

Screening de enfermedad renal crónica en pacientes diabéticos de larga evolución de la UMF (unidad de medicina familiar) 222

Contexto: la nefropatía diabética es la primera causa de enfermedad renal crónica en el mundo, sin embargo, no existe información de la prevalencia de Enfermedad Renal Crónica (ERC) en estadios tempranos en México. Una tarea fundamental del primer nivel de atención es la detección oportuna de enfermedades y la ERC en pacientes diabéticos es subdiagnosticada en estadios tempranos al ser asintomática. Objetivo: determinar la frecuencia y la estadificación de ERC en pacientes con diabetes mellitus tipo 2 de larga evolución en una unidad de primer nivel de atención, en el estado de México. Metodología: estudio transversal descriptivo. Se incluyeron 263 pacientes calculados por fórmula de población finita y selección aleatoria simple. Se incluyeron pacientes con diabetes tipo 2, ≥ 5 años de evolución, sin encontrarse en terapia sustitutiva de la función renal que cumplieran los criterios de inclusión. Las variables de estudio: características sociodemográficas y la estimación de la tasa de filtración glomerular por la ecuación CKD-EPI fueron descritas en frecuencias y porcentajes para variables categóricas y las variables continuas se reportaron medias y de desviación estándar, la diferencia entre grupos fue establecida por medio de prueba de Chi cuadrado o prueba exacta de Fisher y distribución t de student, de acuerdo con el tipo de variable. Un valor de p ˂ 0,05 fue considerado estadísticamente significativo. Resultados: la clasificación Kdigo presenta seis estadios y los resultados con respecto al grado de filtrado glomerular fueron: estadio 1 con 39,5 % (IC 95 %, 34,2-45,6), estadio 2 con 38,8 % (IC 95 %, 32,7-44,5), estadio 3a con 8 % (IC 95 %, 4,9-11,4), estadio 3b con 5,7 % (IC 95 %, 3,4-8,7), estadio 4 con 6,8 % (IC 95 %, 3,8-9,9) y el estadio 5 con 1,1 % (IC 95 % 0,0-2,7). El promedio de edad fue 69,26 ±11,01 en el grupo con ERC, en la segmentación por género estuvo: masculino en el grupo con ERC con 59,6 % y femenino con 40,3 %. Con respecto a comorbilidades, hipertensión arterial y tratamiento al analizarlas en grupos con ausencia de ERC y presencia de ERC fueron estadísticamente significativas, lo mismo en los resultados de laboratorio. Conclusiones: la prevalencia de sospecha de ERC en nuestra población es de 21 %, al menos 1 de cada 5 pacientes diabéticos con ≥ 5 años de evolución padecen una disminución del FG, sin embargo, no podemos considerarla ERC hasta que se valore la presencia de daño renal y corroborarlo a los tres meses.

Background: Diabetic nephropathy is the main cause of chronic kidney disease (CKD), however, there are no data available about the prevalence of chronic kidney disease in the early stages in Mexico. A key role in first level attention consists in performing timely screenings for diseases such as CKD. In most cases CKD is underdiagnosed in early stages, because it is asymptomatic. Purpose: To determine the frequency of CKD in long-standing diabetes type 2 Methods: This was a cross-sectional descriptive study. We included 263 patients with diabetes type 2 with at least 5 years of evolution, not undergoing renal function replacement therapy. The variables of this study were: sociodemographic characteristics and estimation of the glomerular filtration rate through the CKD-EPI equation. Categorical variables were summarized as frequencies and percentages. For continuous variables, mean and standard deviation were reported. The significance of differences between groups was assessed by Student's t-test or square chi or Fisher's exact test, and p-value ≤ 0.05 was considered statistically significant. Results: the KDIGO classification has 5 stages. The results regarding the degree of glomerular filtration: stage 1 with 39.5% (95% CI, 34.2-45.6) , stage 2 with 38.8% ( 95% CI, 32.77-44.5),stage 3a with 8% ( 95% CI, 4.9-11.4), stage 3b with 5.7% (95% CI, 3.4-8.7), grade 4 with 6.8% (95% CI, 3.8-9.9) and stage 5 with 1.1% (95% CI 0.0-2.7). The average age was 69.26 ± 11.01 in the group with CKD. Male gender predominated in the group CKD with 34 (59.6%) and 23 (40.3%), for female. Regarding comorbidities, hypertension arterial and treatment when analyzed for either absence or presence of CKD were statistically significant. The same findings can be obtained in laboratory results. Conclusion: The prevalence of suspected CKD in our population is 21%, at least 1 in 5 diabetic patients with ≥5 years of evolution suffer a decrease in GFR; however, we cannot consider it to be CKD until the presence of kidney damage is assessed and confirmed at 3 months.

Assessment of pre-donation glomerular filtration rate: going back to basics.

The 2017 version of the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines is the most recent international framework for the evaluation and care of living kidneys donors. Along with the call for an integrative approach evaluating the long-term end-stage kidney disease risk for the future potential donor, several recommendations are formulated regarding the pre-donation glomerular filtration rate (GFR) adequacy with no or little consideration for the donor candidate's age or for the importance of using reference methods of GFR measurements. Herein, we question the position of the KDIGO guidelines and discuss the rationale and modalities for a more basic, but no less demanding GFR evaluation enabling a more efficient selection of potential kidney donors.

The Glomerular Filtration Rate: From the Diagnosis of Kidney Function to a Public Health Tool.

The prevalence of chronic kidney disease (CKD) continues to increase worldwide, as well as the associated morbidity and mortality and the consequences on the patients' quality of life and countries' economies. CKD often evolves without being recognized by patients and physicians, although the diagnosis is based on two simple laboratory data: the estimated glomerular filtration rate (eGFR) and urine analysis. To measure GFR, the knowledge about the physiologic processes at the nephron level, the concept of clearance, and the identification of creatinine as a suitable endogenous marker for measuring the creatinine clearance (CrCl) had to be previously developed. On those bases, different equations to calculate CrCl (Cockcroft and Gault, 1976), or estimated GFR (four variables MDRD, 1999; CKD-Epi, 2009, among others) were generated. They all include creatinine and some demographic data, such as sex and age. However, to compare results throughout life or among laboratories, the creatinine determination must be standardized. In addition, the accuracy of these equations remains controversial in certain subgroups of patients. For these reasons, other mathematical models to improve CrCl estimation have been developed, such as when urine cannot be collected, in debilitated elderly patients and patients with trauma, diabetes, or obesity. Currently, eGFR in adults can be measured and reported immediately, using isotope dilution mass spectrometry traceable creatinine-based equations. In conclusion, based on knowledge obtained from renal physiology, eGFR can be used in the clinic for the diagnosis and early treatment of CKD, as well as a public instrument to estimate the prevalence.

The ensemble learning model is not better than the Asian modified CKD-EPI equation for glomerular filtration rate estimation in Chinese CKD patients in the external validation study.

OBJECTIVE: To assess the clinical practicability of the ensemble learning model established by Liu et al. in estimating glomerular filtration rate (GFR) and validate whether it is a better model than the Asian modified Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation in a cohort of Chinese chronic kidney disease (CKD) patients in an external validation study. METHODS: According to the ensemble learning model and the Asian modified CKD-EPI equation, we calculated estimated GFRensemble and GFRCKD-EPI, separately. Diagnostic performance of the two models was assessed and compared by correlation coefficient, regression equation, Bland-Altman analysis, bias, precision and P30 under the premise of 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) dual plasma sample clearance method as reference method for GFR measurement (mGFR). RESULTS: A total of 158 Chinese CKD patients were included in our external validation study. The GFRensemble was highly related with mGFR, with the correlation coefficient of 0.94. However, regression equation of GFRensemble = 0.66*mGFR + 23.05, the regression coefficient was far away from one, and the intercept was wide. Compared with the Asian modified CKD-EPI equation, the diagnostic performance of the ensemble learning model also demonstrated a wider 95% limit of agreement in Bland-Altman analysis (52.6 vs 42.4 ml/min/1.73 m2), a poorer bias (8.0 vs 1.0 ml/min/1.73 m2, P = 0.02), an inferior precision (18.4 vs 12.7 ml/min/1.73 m2, P < 0.001) and a lower P30 (58.9% vs 74.1%, P < 0.001). CONCLUSIONS: Our study showed that the ensemble learning model cannot replace the Asian modified CKD-EPI equation for the first choice for GFR estimation in overall Chinese CKD patients.

Relationship between decline in estimated or measured glomerular filtration rate and 16-year postrenal transplant outcome.

BACKGROUND: Glomerular filtration rate (GFR) decline ≥30% over 2 years can substitute for the conventional 'doubling of serum creatinine' to predict end-stage renal disease in patients with native kidneys. While chronic kidney disease trajectory is less predictable in transplanted patients, recent data have suggested that similar GFR decline might be an acceptable surrogate for long-term transplant outcome. We sought (i) to confirm the prognostic value of an early GFR decline in kidney transplant recipients and (ii) to determine whether using direct measurement of GFR with inulin improves the performance of this surrogate. METHODS: We retrospectively analysed all recipients transplanted between 1989 and 2000 in our centre, with inulin-measured and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)-estimated GFR at 1 and 5 years post-transplant, and evaluated the performance [time-dependent area under the receiver operating characteristic curve (ROC AUC) and subdistribution hazard ratio (sdHR) with competing risk model] of GFR change to predict graft failure and all-cause mortality. RESULTS: Out of 417 kidney transplant recipients, 116 patients had lost their graft and 77 had died 16 years after transplantation. While being significantly associated with graft failure [sdHR = 2.37 (95% confidence interval 1.47-3.83)], CKD-EPI-GFR decline ≥30% failed to appropriately predict long-term graft survival (C-statistics of 0.63). Concordance between inulin-GFR and CKD-EPI-GFR to detect similar GFR change was only 53%. Inulin-GFR change was, however, not a better predictor (C-statistics of 0.59). Comparable results were observed for mortality. CONCLUSIONS: Our data suggest that early GFR decline is a poor surrogate for long-term transplant outcome, even when change in GFR is directly measured by a reference method.

Prevalence and determinants of chronic kidney disease in urban adults' populations of northern Cameroon.

BACKGROUND: Chronic kidney disease (CKD) is a major health problem with growing prevalence in sub-Saharan Africa. AIM: Assess the prevalence and determinants of CKD in Garoua and Figuil cities of the North region of Cameroon. METHODS: A cross-sectional survey was conducted from January to June 2018 in the two cities, using a multi-level cluster sampling. All adults with low estimated glomerular filtration rate (eGFR) (< 60 ml/min/1.73 m2) by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and/or albuminuria (≥ 30 mg/g) were reviewed three months later. Logistic regression models (accounting for the sampling strategy) were used to investigate the predictors of the outcomes. RESULTS: A total of 433 participants were included, with a mean age (95%CI) of 45.0 (43.4-46.6) years, 212 (48.7%) men, 294 (67.9%) from Garoua and 218 (45.6%) with no formal education. Risk factors for chronic nephropathy were highly prevalent including longstanding use of street medications (52.8%), herbal medicines (50.2%) and non-steroidal anti-inflammatory drugs (50%), alcohol consumption (34.4%), hypertension (33.9%), overweight/obesity (33.6%), hyperuricemia (16.8%), smoking (11.3%) and hyperglycemia (6.5%). The prevalence of CKD was 11.7% overall, 10.7% in Garoua and 13% in Figuil participants. Equivalents figures for CKD G3-5 and albuminuria were 2.8%, 2.0% and 4.5%; and 9.1%, 9.3% and 8.5%, respectively. History of diabetes, increase systolic blood pressure, hyperglycemia and hyperuricemia were predictors of CKD. CONCLUSION: The prevalence of CKD is as high in these northern cities as previously reported in southern cities of Cameroon, driven mostly by known modifiable risk factors of chronic nephropathy.

Comparative performance of FAS equation and Asian modified CKD-EPI in the determination of GFR in Chinese patients with CKD with the 99mTc-DTPA plasma clearance as the reference method.

BACKGROUND: Glomerular filtration rate (GFR) is a useful index in many clinical conditions. However, very few studies have assessed the performance of full age spectrum (FAS) equation and the Asian modified Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation in the approximation of GFR in Chinese patients with chronic kidney disease. OBJECTIVE: This study aimed to compare the diagnostic performance of the above two creatinine-based equations. METHODS: A well designed single-center cross-sectional study was performed and the GFR was determined by 3 methods separately in the same day: technetium-99m-diethylene triamine pentaacetic acid (99mTc-DTPA) dual plasma sample clearance method (mGFR); FAS equation method; Asian modified CKD-EPI equation method. The gold standard method was the mGFR. Equations performance criteria considered correlation coefficient, bias, precision, accuracy and the ability to detect the mGFR less than 60ml/min/1.73m2. RESULTS: A total of 160 patients were enrolled. The diagnostic performance of FAS showed no significant difference in the correlation coefficient (0.89 vs 0.89), precision (15.9 vs 16.1ml/min/1.73m2), accuracy (75.0% vs 76.3%) and the ability to detect the mGFR less than 60ml/min/1.73m2 (0.94 vs 0.94) compared with the Asian modified CKD-EPI equation in all participants. The FAS showed a negative bias, while the new CKD-EPI equation showed a positive bias (-1.20 vs 1.30ml/min/1.73m2, P<0.001). However, they were all near to zero. In the mGFR<60ml/min/1.73m2 subgroup and mGFR>60ml/min/1.73m2 subgroup were consistent with that in the whole cohort. The precision and accuracy decreased when GFR>60ml/min/1.73m2 in both equations. CONCLUSIONS: The FAS equation and the Asian modified CKD-EPI equation had similar performance in determining the glomerular filtration rate in the Chinese patients with chronic kidney disease. Both the FAS equation and Asian modified CKD-EPI can be a satisfactory method and may be the most suitable creatinine-based equation.

Performance of 4 Creatinine-based Equations in Assessing Glomerular Filtration Rate in Adults with Diabetes.

AIMS: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: In adults with diabetes the revised Lund-Malmö performs better than MDRD, CKD-EPI, and FAS in calculating point estimates of GFR.

Comparative performance of FAS equation and Asian modified CKD-EPI in the determination of GFR in Chinese patients with CKD with the 99mTc-DTPA plasma clearance as the reference method.

BACKGROUND: Glomerular filtration rate (GFR) is a useful index in many clinical conditions. However, very few studies have assessed the performance of full age spectrum (FAS) equation and the Asian modified Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation in the approximation of GFR in Chinese patients with chronic kidney disease. OBJECTIVE: This study aimed to compare the diagnostic performance of the above two creatinine-based equations. METHODS: A well designed single-center cross-sectional study was performed and the GFR was determined by 3 methods separately in the same day: technetium-99m-diethylene triamine pentaacetic acid (99mTc-DTPA) dual plasma sample clearance method (mGFR); FAS equation method; Asian modified CKD-EPI equation method. The gold standard method was the mGFR. Equations performance criteria considered correlation coefficient, bias, precision, accuracy and the ability to detect the mGFR less than 60ml/min/1.73m2. RESULTS: A total of 160 patients were enrolled. The diagnostic performance of FAS showed no significant difference in the correlation coefficient (0.89 vs 0.89), precision (15.9 vs 16.1ml/min/1.73m2), accuracy (75.0% vs 76.3%) and the ability to detect the mGFR less than 60ml/min/1.73m2 (0.94 vs 0.94) compared with the Asian modified CKD-EPI equation in all participants. The FAS showed a negative bias, while the new CKD-EPI equation showed a positive bias (-1.20 vs 1.30ml/min/1.73m2, P<0.001). However, they were all near to zero. In the mGFR<60ml/min/1.73m2 subgroup and mGFR>60ml/min/1.73m2 subgroup were consistent with that in the whole cohort. The precision and accuracy decreased when GFR>60ml/min/1.73m2 in both equations. CONCLUSIONS: The FAS equation and the Asian modified CKD-EPI equation had similar performance in determining the glomerular filtration rate in the Chinese patients with chronic kidney disease. Both the FAS equation and Asian modified CKD-EPI can be a satisfactory method and may be the most suitable creatinine-based equation.