Performance of MDRD-IDMS and CKD-EPI equations in Mexican individuals with normal renal function
Funcionamiento de las fórmulas MDRD-IDMS y CKD-EPI, en individuos mexicanos con función renal normal
Read
15734
Timeswas read the article
3597
Total PDF
12137
Total HTML
Share statistics
array:21 [ "pii" => "X2013251414054601" "issn" => "20132514" "doi" => "10.3265/Nefrologia.pre2014.Jun.12538" "estado" => "S300" "fechaPublicacion" => "2014-09-01" "documento" => "article" "licencia" => "http://www.elsevier.com/open-access/userlicense/1.0/" "subdocumento" => "fla" "cita" => "Nefrologia (English Version). 2014;34:591-8" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:2 [ "total" => 8650 "formatos" => array:3 [ "EPUB" => 318 "HTML" => 7536 "PDF" => 796 ] ] "Traduccion" => array:1 [ "es" => array:17 [ "pii" => "X0211699514054604" "issn" => "02116995" "doi" => "10.3265/Nefrologia.pre2014.Jun.12538" "estado" => "S300" "fechaPublicacion" => "2014-09-01" "documento" => "article" "licencia" => "http://www.elsevier.com/open-access/userlicense/1.0/" "subdocumento" => "fla" "cita" => "Nefrologia. 2014;34:591-8" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:2 [ "total" => 52576 "formatos" => array:3 [ "EPUB" => 316 "HTML" => 50317 "PDF" => 1943 ] ] "es" => array:12 [ "idiomaDefecto" => true "titulo" => "Funcionamiento de las fórmulas MDRD-IDMS y CKD-EPI, en individuos mexicanos con función renal normal" "tienePdf" => "es" "tieneTextoCompleto" => "es" "tieneResumen" => array:2 [ 0 => "es" 1 => "en" ] "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "591" "paginaFinal" => "598" ] ] "titulosAlternativos" => array:1 [ "en" => array:1 [ "titulo" => "Performance of MDRD-IDMS and CKD-EPI equations in Mexican individuals with normal renal function" ] ] "contieneResumen" => array:2 [ "es" => true "en" => true ] "contieneTextoCompleto" => array:1 [ "es" => true ] "contienePdf" => array:1 [ "es" => true ] "resumenGrafico" => array:2 [ "original" => 0 "multimedia" => array:8 [ "identificador" => "fig1" "etiqueta" => "Tab. 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12538_19904_58182_es_12538_t1.jpg" "Alto" => 274 "Ancho" => 424 "Tamanyo" => 135739 ] ] "descripcion" => array:1 [ "es" => "Características generales de la población estudiada" ] ] ] "autores" => array:1 [ 0 => array:2 [ "autoresLista" => "José M. Arreola-Guerra, Rodolfo Rincón-Pedrero, Cristino Cruz-Rivera, Teresa Belmont-Pérez, Ricardo Correa-Rotter, José A. Niño-Cruz" "autores" => array:6 [ 0 => array:2 [ "nombre" => "José M." "apellidos" => "Arreola-Guerra" ] 1 => array:2 [ "nombre" => "Rodolfo" "apellidos" => "Rincón-Pedrero" ] 2 => array:2 [ "nombre" => "Cristino" "apellidos" => "Cruz-Rivera" ] 3 => array:2 [ "nombre" => "Teresa" "apellidos" => "Belmont-Pérez" ] 4 => array:2 [ "nombre" => "Ricardo" "apellidos" => "Correa-Rotter" ] 5 => array:2 [ "nombre" => "José A." "apellidos" => "Niño-Cruz" ] ] ] ] ] "idiomaDefecto" => "es" "Traduccion" => array:1 [ "en" => array:9 [ "pii" => "X2013251414054601" "doi" => "10.3265/Nefrologia.pre2014.Jun.12538" "estado" => "S300" "subdocumento" => "" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:1 [ "total" => 0 ] "idiomaDefecto" => "en" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/X2013251414054601?idApp=UINPBA000064" ] ] "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/X0211699514054604?idApp=UINPBA000064" "url" => "/02116995/0000003400000005/v0_201502091337/X0211699514054604/v0_201502091337/es/main.assets" ] ] "itemSiguiente" => array:17 [ "pii" => "X2013251414054597" "issn" => "20132514" "doi" => "10.3265/Nefrologia.pre2014.Apr.12508" "estado" => "S300" "fechaPublicacion" => "2014-09-01" "documento" => "article" "licencia" => "http://www.elsevier.com/open-access/userlicense/1.0/" "subdocumento" => "fla" "cita" => "Nefrologia (English Version). 2014;34:599-604" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:2 [ "total" => 6993 "formatos" => array:3 [ "EPUB" => 305 "HTML" => 5670 "PDF" => 1018 ] ] "en" => array:12 [ "idiomaDefecto" => true "titulo" => "Impact of the 5008 monitor software update on total convective volume" "tienePdf" => "en" "tieneTextoCompleto" => "en" "tieneResumen" => array:2 [ 0 => "es" 1 => "en" ] "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "599" "paginaFinal" => "604" ] ] "titulosAlternativos" => array:1 [ "es" => array:1 [ "titulo" => "Repercusión de la actualización del software del monitor 5008 en el volumen convectivo total" ] ] "contieneResumen" => array:2 [ "es" => true "en" => true ] "contieneTextoCompleto" => array:1 [ "en" => true ] "contienePdf" => array:1 [ "en" => true ] "resumenGrafico" => array:2 [ "original" => 0 "multimedia" => array:8 [ "identificador" => "fig1" "etiqueta" => "Tab. 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12508_16025_59805_en_t112508_02.jpg" "Alto" => 1023 "Ancho" => 2141 "Tamanyo" => 448956 ] ] "descripcion" => array:1 [ "en" => "Comparison of laboratory data and dialysis parameters between dialysis periods using a 5008 monitor and a 5008 CorDiax monitor (n=63)" ] ] ] "autores" => array:1 [ 0 => array:2 [ "autoresLista" => "Francisco Maduell, Néstor Rodríguez, Laura Sahdala, Laura Sahdalá, Diego Coronel, Marta Arias Guillén, Raquel Ojeda, Manel Vera, Néstor Fontseré, Aleix Cases, Josep M. Campistol" "autores" => array:11 [ 0 => array:2 [ "nombre" => "Francisco" "apellidos" => "Maduell" ] 1 => array:2 [ "nombre" => "Néstor" "apellidos" => "Rodríguez" ] 2 => array:2 [ "nombre" => "Laura" "apellidos" => "Sahdala" ] 3 => array:2 [ "nombre" => "Laura" "apellidos" => "Sahdalá" ] 4 => array:2 [ "nombre" => "Diego" "apellidos" => "Coronel" ] 5 => array:2 [ "nombre" => "Marta" "apellidos" => "Arias Guillén" ] 6 => array:2 [ "nombre" => "Raquel" "apellidos" => "Ojeda" ] 7 => array:2 [ "nombre" => "Manel" "apellidos" => "Vera" ] 8 => array:2 [ "nombre" => "Néstor" "apellidos" => "Fontseré" ] 9 => array:2 [ "nombre" => "Aleix" "apellidos" => "Cases" ] 10 => array:2 [ "nombre" => "Josep M." "apellidos" => "Campistol" ] ] ] ] ] "idiomaDefecto" => "en" "Traduccion" => array:1 [ "es" => array:9 [ "pii" => "X021169951405459X" "doi" => "10.3265/Nefrologia.pre2014.Apr.12508" "estado" => "S300" "subdocumento" => "" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:1 [ "total" => 0 ] "idiomaDefecto" => "es" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/X021169951405459X?idApp=UINPBA000064" ] ] "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/X2013251414054597?idApp=UINPBA000064" "url" => "/20132514/0000003400000005/v0_201502091605/X2013251414054597/v0_201502091605/en/main.assets" ] "itemAnterior" => array:17 [ "pii" => "X201325141405461X" "issn" => "20132514" "doi" => "10.3265/Nefrologia.pre2014.Jun.12281" "estado" => "S300" "fechaPublicacion" => "2014-09-01" "documento" => "article" "licencia" => "http://www.elsevier.com/open-access/userlicense/1.0/" "subdocumento" => "fla" "cita" => "Nefrologia (English Version). 2014;34:584-90" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:2 [ "total" => 5873 "formatos" => array:3 [ "EPUB" => 294 "HTML" => 4847 "PDF" => 732 ] ] "en" => array:12 [ "idiomaDefecto" => true "titulo" => "Determination of peritoneal phosphate transport as a tool for controlling serum phosphorus" "tienePdf" => "en" "tieneTextoCompleto" => "en" "tieneResumen" => array:2 [ 0 => "es" 1 => "en" ] "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "584" "paginaFinal" => "590" ] ] "titulosAlternativos" => array:1 [ "es" => array:1 [ "titulo" => "Determinación del transporte peritoneal de fósforo como herramienta para el control del fósforo sérico" ] ] "contieneResumen" => array:2 [ "es" => true "en" => true ] "contieneTextoCompleto" => array:1 [ "en" => true ] "contienePdf" => array:1 [ "en" => true ] "resumenGrafico" => array:2 [ "original" => 0 "multimedia" => array:8 [ "identificador" => "fig1" "etiqueta" => "Tab. 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12281_16025_61888_en_t112281.jpg" "Alto" => 1345 "Ancho" => 2145 "Tamanyo" => 381952 ] ] "descripcion" => array:1 [ "en" => "Population characteristics: medical and dialysis management" ] ] ] "autores" => array:1 [ 0 => array:2 [ "autoresLista" => "Eduardo A. López-Guerra, Víctor H. Rodríguez-García, Francisco E. Rodríguez-Castellanos" "autores" => array:4 [ 0 => array:2 [ "nombre" => "Eduardo A." "apellidos" => "López-Guerra" ] 1 => array:2 [ "nombre" => "Eduardo A." "apellidos" => "López-Guerra" ] 2 => array:2 [ "nombre" => "Víctor H." "apellidos" => "Rodríguez-García" ] 3 => array:2 [ "nombre" => "Francisco E." "apellidos" => "Rodríguez-Castellanos" ] ] ] ] ] "idiomaDefecto" => "en" "Traduccion" => array:1 [ "es" => array:9 [ "pii" => "X0211699514054612" "doi" => "10.3265/Nefrologia.pre2014.Jun.12281" "estado" => "S300" "subdocumento" => "" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:1 [ "total" => 0 ] "idiomaDefecto" => "es" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/X0211699514054612?idApp=UINPBA000064" ] ] "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/X201325141405461X?idApp=UINPBA000064" "url" => "/20132514/0000003400000005/v0_201502091605/X201325141405461X/v0_201502091605/en/main.assets" ] "en" => array:15 [ "idiomaDefecto" => true "titulo" => "Performance of MDRD-IDMS and CKD-EPI equations in Mexican individuals with normal renal function" "tieneTextoCompleto" => true "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "591" "paginaFinal" => "598" ] ] "autores" => array:1 [ 0 => array:3 [ "autoresLista" => "José M. Arreola-Guerra, Rodolfo Rincón-Pedrero, Cristino Cruz-Rivera, Teresa Belmont-Pérez, Ricardo Correa-Rotter, José A. Niño-Cruz" "autores" => array:6 [ 0 => array:3 [ "nombre" => "José M." "apellidos" => "Arreola-Guerra" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "<span class="elsevierStyleSup">a</span>" "identificador" => "affa" ] ] ] 1 => array:3 [ "nombre" => "Rodolfo" "apellidos" => "Rincón-Pedrero" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "<span class="elsevierStyleSup">a</span>" "identificador" => "affa" ] ] ] 2 => array:3 [ "nombre" => "Cristino" "apellidos" => "Cruz-Rivera" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "<span class="elsevierStyleSup">a</span>" "identificador" => "affa" ] ] ] 3 => array:3 [ "nombre" => "Teresa" "apellidos" => "Belmont-Pérez" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "<span class="elsevierStyleSup">a</span>" "identificador" => "affa" ] ] ] 4 => array:3 [ "nombre" => "Ricardo" "apellidos" => "Correa-Rotter" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "<span class="elsevierStyleSup">a</span>" "identificador" => "affa" ] ] ] 5 => array:4 [ "nombre" => "José A." "apellidos" => "Niño-Cruz" "email" => array:1 [ 0 => "janino@nefros.com" ] "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "<span class="elsevierStyleSup">a</span>" "identificador" => "affa" ] ] ] ] "afiliaciones" => array:1 [ 0 => array:3 [ "entidad" => "Servicio de Nefrología y Metabolismo Mineral, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Ciudad de México, Distrito Federal, México, " "etiqueta" => "<span class="elsevierStyleSup">a</span>" "identificador" => "affa" ] ] ] ] "titulosAlternativos" => array:1 [ "es" => array:1 [ "titulo" => "Funcionamiento de las fórmulas MDRD-IDMS y CKD-EPI, en individuos mexicanos con función renal normal" ] ] "resumenGrafico" => array:2 [ "original" => 0 "multimedia" => array:8 [ "identificador" => "fig1" "etiqueta" => "Tab. 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12538_16025_61172_en_t112538i.jpg" "Alto" => 673 "Ancho" => 1043 "Tamanyo" => 181156 ] ] "descripcion" => array:1 [ "en" => "General characteristics of the study population" ] ] ] "textoCompleto" => "<p class="elsevierStylePara"><span class="elsevierStyleBold">INTRODUCTION</span></p><p class="elsevierStylePara"><span class="elsevierStyleBold"> </span></p><p class="elsevierStylePara">Estimation of the glomerular filtration rate (eGFR) using formulae has become widespread worldwide. By calculating the eGFR, we can classify patients in different chronic kidney disease (CKD) stages and estimate its prevalence in various populations. EGFR is a valid endpoint in clinical trials and in many situations in daily medical practice. Moreover, it provides a prognosis value for mortality or the requirement for renal replacement therapy<span class="elsevierStyleSup">1</span>.</p><p class="elsevierStylePara">The main precedent dates back to 1976, when Cockcroft and Gault (CandG) proposed their formula for estimating the glomerular filtration rate<span class="elsevierStyleSup">2</span>. This, in combination with creatinine clearance in 24-hour urine, was the only alternative used in clinical practice for many years. However, both tests overestimate renal function<span class="elsevierStyleSup">3</span>. It was not until 1999 when Levey et al. created a new formula derived from the Modification of Diet in Renal Disease Study (MDRD) that factors such as age, race, sex, serum creatinine, blood urea nitrogen and serum albumin were included. This formula performed better than that of CandG<span class="elsevierStyleSup">4,5</span>.</p><p class="elsevierStylePara">The limitations in the validity of this formula originate in the population from which it was created, since the vast majority of individuals recruited were white, without diabetes mellitus (DM) and with a GFR of less than 60ml/min/1.73m<span class="elsevierStyleSup">2</span>. The main bias shown was that the formula does not perform as well as the GFR increases, and as such, the real prevalence of CKD is overestimated<span class="elsevierStyleSup">6</span>.</p><p class="elsevierStylePara">For this reason, the same group of researchers created a new formula derived from the CKD-EPI study (Chronic Kidney Disease Epidemiology Collaboration). In this study, 8254 individuals were analysed, of which the data of 5504 (66.6%) were used to create the formula and the 2750 (33.3%) remaining individuals were used for its validation. 71% of individuals included were considered to be at high risk of CKD and 29% had type 2 DM. Moreover, 60% were white and the average age was 47 years old<span class="elsevierStyleSup">7</span>. Initially, the variables of the MDRD study were taken into account and the following were additionally included: weight, a history of kidney transplantation and type 2 DM. After the analysis, significant variables were as follows: age, sex, race (African American versus white) and standardised serum creatinine, and as such, only these variables were included in the final formula<span class="elsevierStyleSup">7</span>. In the analysis, we observed that the formula performed similarly to the MDRD formula in the CKD population (defined as a GFR <60ml/min/1.73m<span class="elsevierStyleSup">2</span>), but better in the population with a GFR >60ml/min/1.73m<span class="elsevierStyleSup">2</span>.</p><p class="elsevierStylePara">A fact of great epidemiological importance was that on the basis of the National Health and Nutrition Examination Survey (NHANES III), in which the MDRD formula had found a CKD prevalence of 13% in the United States, this prevalence was reduced to 11% with the CKD-EPI formula. Recently, after a mean follow-up of 14 years after this estimation, it was found that individuals reclassified to higher kidney damage stages with CKD-EPI had greater cardiovascular mortality. Likewise, individuals reclassified to lower kidney damage stages had lower cardiovascular mortality, suggesting that the difference in classification between MDRD and CKD-EPI is due to a better screening of individuals who really have CKD<span class="elsevierStyleSup">8</span>.</p><p class="elsevierStylePara">One limitation in the generalisation of these formulae was that they performed better in the group of individuals from which they were obtained. In 2010, on the basis of the different ethnic groups included in the CKD-EPI study, an adjustment formula was proposed for the following race groups: black, Asian, Hispanic and white. For the internal validation, 4014 individuals were taken from European studies and 1022 from Asian studies (Japan and China). The formula with four variables showed an improvement in performance in the Chinese population, while its validity was poor in the Japanese population. There was no significant improvement in the bias of Hispanics, and as such, we can conclude that the two-tiered CKD-EPI formula (African American and white/others) may be reliably used in the United States and Europe, with Hispanics who reside in these regions being included<span class="elsevierStyleSup">9</span>.</p><p class="elsevierStylePara">We should highlight certain aspects about the selection of individuals for the ethnic group of Hispanics who live in the United States, which may not be equivalent for the Mexican population. Firstly, Hispanic (Latino) patients were grouped with Native Americans with the justification that they share the same anthropological origin. Another aspect is the average body mass index (BMI) of individuals in this group, which was 31kg/m<span class="elsevierStyleSup">2</span>, and that 54% had a BMI greater than 30kg/m<span class="elsevierStyleSup">2</span>.</p><p class="elsevierStylePara">Another matter examined was the validation of the CKD-EPI formula in individuals at a high risk of progressing to CKD, such as obese individuals, those with type 2 DM and those with a kidney transplant. None of these variables contributed significant changes to the performance of the formula. When it was adjusted for weight, there was a slight improvement in the mean bias in BMI below 20kg/m<span class="elsevierStyleSup">2 </span>(-3.2 versus 0.1). However, the authors dismissed it because the validation study had a greater amount of individuals with a low BMI than the original. As such, the authors do not recommend the adjustment for any of these variables. The tendency<span class="elsevierStyleSup">10</span>, even when discreet, to overestimate the GFR in individuals with a BMI of less than 20kg/m<span class="elsevierStyleSup">2</span> is striking.</p><p class="elsevierStylePara">As such, we can conclude that in spite of this formula having demonstrated its validity in a Latino population born or residing in the United States, we cannot necessarily extrapolate the information of these articles to our population native to and living in Mexico.</p><p class="elsevierStylePara">The objective of this study was to compare the performance of the CKD-EPI and MDRD estimation formulae in a healthy adult Mexican population, taking as a reference standard the measurement of the GFR using Tc<span class="elsevierStyleSup">99</span>DTPA. A secondary and post-hoc analysis of the variables included was carried out in order to assess their involvement in the performance of the CKD-EPI formula.</p><p class="elsevierStylePara"> </p><p class="elsevierStylePara"><span class="elsevierStyleBold">MATERIAL AND METHOD</span></p><p class="elsevierStylePara"><span class="elsevierStyleBold"> </span></p><p class="elsevierStylePara">This was a cross-sectional, observational and open study to compare the performance of two GFR estimation formulae: CKD-EPI and MDRD. The gold standard for determining the measured glomerular filtration rate (mGFR) was Tc<span class="elsevierStyleSup">99</span>DTPA clearance in urine. Tc<span class="elsevierStyleSup">99</span>DTPA administration began at the end of a hydration period with a loading dose of 150μCi bolus and subsequently a 300μCi 240-minute infusion. After a 60-minute balance period, we started taking samples (urine and blood) every half hour over four periods (we only considered the three last periods at 120, 150 and 180 minutes for calculation of the glomerular filtration rate). The samples were analysed in duplicate in a gamma counter (Packard<span class="elsevierStyleSup">®</span> COBRA II, EUA), recording the activity of a millimetre of each tube over a minute (counts/ml/min). The urine samples were obtained by spontaneous voiding and blood samples by venepuncture in the arm contralateral to the infusion. Clearance was calculated with the formula UxV/[(P1+P2+P3)/3], with U = counts in a millimetre of urine, V = 240-minute urine volume, and P1, P2 and P3 = counts in plasma at minute 120, 150 and 180, respectively. The GFR was adjusted to 1.73m<span class="elsevierStyleSup">2 </span>of body surface.</p><p class="elsevierStylePara">We included adult Mexican individuals (between 18 and 75 years of age) without known comorbidities in the medical history. We excluded those with measured creatinine greater than 1.5mg/dl in previous studies, iodine allergy and pregnancy. Exclusion criteria were: withdrawal of informed consent, incomplete (anthropometric or laboratory) data, presence of comorbidities or serum creatinine greater than 1.5mg/dl in the screening sample. The creatinine measurement used was standardised based on recommended standards<span class="elsevierStyleSup">11</span> (kinetic Jaffe method. Syncron System, Beckman Coulter, Ireland). For the MDRD-IDMS estimation formula, we used the previously validated four-variable equation with standardised creatinine<span class="elsevierStyleSup">12</span>. The protocol was designed in accordance with the Declaration of Helsinki criteria. This study was submitted to and approved by the ethics committee of the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INNSZ), in Mexico City.</p><p class="elsevierStylePara">We used descriptive statistics in accordance with the variable measurement level. The results are displayed as frequencies and percentages for categorical variables and as means with standard deviation for continuous variables.</p><p class="elsevierStylePara">On the basis of the parameters most used for validating the performance of GFR estimation formulae, we used the following:</p><p class="elsevierStylePara">a)    Bias = measured GFR – estimated GFR.</p><p class="elsevierStylePara">b)    Bias (%) = (measured GFR – estimated GFR) ÷ measured GFR.</p><p class="elsevierStylePara">c)     Accuracy p(30) = percentage of estimated GFR within 30% of the measured GFR.</p><p class="elsevierStylePara">d)    Pearson correlation (r<span class="elsevierStyleSup">2</span>).</p><p class="elsevierStylePara">e)    Precision = interquartile range (IQR).</p><p class="elsevierStylePara">We should stress that the results of the bias with a minus sign refer to an overestimation of the mGFR, while the results with a positive sign refer to an underestimation of the mGFR.</p><p class="elsevierStylePara">The results were analysed with the paired t-test for bias and bias%, with 95% confidence intervals (95% CI). For the accuracy variable, we used the χ<span class="elsevierStyleSup">2 </span>test. We considered a <span class="elsevierStyleItalic">P</span>-value of <.05 to be statistically significant.</p><p class="elsevierStylePara">To analyse variables that affect the performance of the CKD-EPI formula, we used a multiple linear regression, with the bias as a dependent variable. We analysed the significant variables in the subgroups and compared all the determinants of formula performance. We used Microsoft Excel 2010 and STATA version 11 to analyse the data.</p><p class="elsevierStylePara"> </p><p class="elsevierStylePara"><span class="elsevierStyleBold">RESULTS</span></p><p class="elsevierStylePara"><span class="elsevierStyleBold"> </span></p><p class="elsevierStylePara">Between April 2010 and June 2011, we recruited 120 healthy individuals, of which only 97 displayed all of the criteria necessary for the final analysis. The main reason for exclusion was incomplete data in the laboratory or of the measurement technique with Tc<span class="elsevierStyleSup">99</span>DTPA. In 5 individuals, the reason for exclusion was serum creatinine greater than 1.5mg/dl. The main characteristics of the selected patients are shown in Table 1.</p><p class="elsevierStylePara">The average age was 35.8 years (min-max 18 to 73) and most participants were between 20 and 50 years of age (78.2%). The individuals included were mostly workers of the INNSZ and potential kidney donors.</p><p class="elsevierStylePara">Average creatinine was 0.76mg/dl and 45.3% of individuals were overweight or obese. The rest of the variables and their ranges are expressed in Table 2.</p><p class="elsevierStylePara">The mean mGFR by Tc<span class="elsevierStyleSup">99</span>DTPA was 102.7ml/min/1.73m<span class="elsevierStyleSup">2</span>. 75.1% of individuals had an mGFR greater than 90ml/min/1.73m<span class="elsevierStyleSup">2</span>.</p><p class="elsevierStylePara"> </p><p class="elsevierStylePara"><span class="elsevierStyleBold">Performance of the formulae</span></p><p class="elsevierStylePara"> </p><p class="elsevierStylePara">The mean GFR estimated by CKD-EPI was 112.7ml/min/1.73m<span class="elsevierStyleSup">2</span>, while for MDRD it was 118.8ml/min/1.73m<span class="elsevierStyleSup">2</span>. In all validation points, CKD-EPI had a better performance than MDRD-IDMS. The bias, defined as mGFR – eGFR, for CKD-EPI was -10.01ml/min/1.73m<span class="elsevierStyleSup">2</span>, 95% CI (-13.2 to -6.8), and for MDRD -16.1ml/min/1.73m<span class="elsevierStyleSup">2</span>, 95% CI (-21.4 to -10.7). On comparing the biases of both formulae, the difference was 6.08ml/min/1.73m<span class="elsevierStyleSup">2</span>, 95% CI (2.58 to 9.58), with statistical significance (<span class="elsevierStyleItalic">p</span><.001). Likewise, the correlation for CKD-EPI was r=0.65 and for MDRD-IDMS it was r=0.52 (Figure 1). The rest of the performance variables are displayed in Tables 3 and 4. Accuracy, represented as p(30), was also higher for CKD-EPI than for MDRD-IDMS (Figure 2).</p><p class="elsevierStylePara"> </p><p class="elsevierStylePara"><span class="elsevierStyleBold">Subgroup analysis</span></p><p class="elsevierStylePara"> </p><p class="elsevierStylePara">Only BMI was significant in the prediction of the performance of the CKD-EPI formula (β 0.82, 95% CI 0.085 to 1.56; <span class="elsevierStyleItalic">p</span>=.029). Neither age nor sex displayed a significant value in the formula performance (Table 5).</p><p class="elsevierStylePara">When we divided groups into over and under 25kg/m<span class="elsevierStyleSup">2</span>, we found a difference in the mean of the statistically significant bias (difference of means 7.39, 95% CI 1.17 to 13.6; <span class="elsevierStyleItalic">P</span><.02) (Figure 3). When they were divided into BMI subgroups, CKD-EPI performance improved as BMI increased, with there being an r<span class="elsevierStyleSup">2 </span>value of 0.46 and 0.82 in the under 21kg/m<span class="elsevierStyleSup">2</span> and over 30kg/m<span class="elsevierStyleSup">2</span> BMI groups, respectively (Table 6).</p><p class="elsevierStylePara">We also found that this was the case with the MDRD formula, although to a lesser extent. Individuals with a BMI greater than 25kg/m<span class="elsevierStyleSup">2 </span>had a bias of -12.31, while those with a BMI less than 25 kg/m<span class="elsevierStyleSup">2 </span>had a bias of -19.9ml/min/1.73 m<span class="elsevierStyleSup">2</span>.</p><p class="elsevierStylePara"><span class="elsevierStyleBold"> </span></p><p class="elsevierStylePara"><span class="elsevierStyleBold">DISCUSSION</span></p><p class="elsevierStylePara"> </p><p class="elsevierStylePara">This is the first study that has aimed to compare the performance of the MDRD-IDMS and CKD-EPI formulae in a Mexican population with renal function >60ml/min/1.73m<span class="elsevierStyleSup">2</span>. The reference standard was measurement of the GFR using Tc<span class="elsevierStyleSup">99</span>DTPA, which was recently validated in Mexican individuals. In this study, we found a bias of +3ml/min/1.73m<span class="elsevierStyleSup">2</span> and r<span class="elsevierStyleSup">2</span>=0.94, taking insulin clearance as the gold standard<span class="elsevierStyleSup">13</span>.</p><p class="elsevierStylePara">The only precedent in relation to the validation of estimation formulae in Hispanic individuals that undoubtedly includes a significant number of individuals from Mexico was the abovementioned trial carried out in the United States for different ethnic groups living in the country. In this study, Native American and Hispanic individuals (from any Latin American country), were grouped together, in which a considerable number were individuals with Mexican parents or ancestors and/or were Mexicans living in the United States. 353 people were studied and the initial characteristics showed that there were 80% who were overweight or obese. Its conclusion with respect to the validity of the CKD-EPI formula was that for the Hispanic population residing in the United States, no adjustment was required for their ethnicity and that the “white and others” CKD-EPI level was that which had to be used reliably<span class="elsevierStyleSup">9</span>. However, although the ethnicity may be Hispanic, United States residency and the degree of obesity of the sample mean that it may not be possible to extrapolate the results to our country. Furthermore, regardless of racial background, being an emigrant from a Latin American country identifies these individuals as Hispanic. As such, it was necessary to recruit individuals in the country of origin to validate the estimation formulae.</p><p class="elsevierStylePara">In our study group, in line with the worldwide literature, CKD-EPI performance was statistically better in all validation categories than MDRD, which was to be expected due to the greater heterogeneity of the population in which this formula was created and validated.</p><p class="elsevierStylePara">When we compared our results with those reported in the original CKD-EPI study, the difference in the performance of the formula was notable. The internal CKD-EPI validation study only reported groups greater than and less than 60ml/min/1.73m<span class="elsevierStyleSup">2</span>. The bias mean in those of more than 60ml/min/1.73m<span class="elsevierStyleSup">2</span> was 3.5 (95% CI from 2.6 to 4.5), which was significantly better than MDRD, which had a bias of 10.6 (9.8 to 11.3), an exceptional difference<span class="elsevierStyleSup">7</span> of 7.1ml/min/1.73m<span class="elsevierStyleSup">2</span>. In the external validation study, levels were reported from 90 to 119 and more than 120ml/min/1.73m<span class="elsevierStyleSup">2</span>. In these two categories, the performance of the formula continued to be very notable. In the group from 90 to 119ml/min/1.73m<span class="elsevierStyleSup">2</span>, the CKD-EPI bias was 1.9 (95% CI 0.2 to 4), while for MDRD, it was 10 (95% CI 6.9 to 11.3). In the >120ml/min/1.73m<span class="elsevierStyleSup">2</span> level, there was a CKD-EPI bias of -2.9 (-5.1 to -0.1) and a MDRD bias of -8.0 (-9.8 to -2.7)<span class="elsevierStyleSup">14</span>. These data, when compared with our results, display a CKD-EPI formula performance in our population that is similar to that of MDRD in the United States, and clearly far from the CKD-EPI performance in this population.</p><p class="elsevierStylePara">A CKD-EPI formula validation study was recently published based on cystatin C by the same team of researchers<span class="elsevierStyleSup">15</span>. An interesting finding from this study was that in the GFR group greater than 90ml/min/1.73m<span class="elsevierStyleSup">2</span>, there was an average bias of 11.1 (95% CI 8.0 to 12.5), a precision defined as IQR 25 (21.6 to 28.1) with an accuracy (p30) of 92%. These data are very similar to those that we obtained in our study group, and as such, we believe that the CKD-EPI performance in our population is acceptable.</p><p class="elsevierStylePara">In a post hoc analysis, on observing the difference between the performance of the formula in our study and the original study, we carried out an analysis in which only BMI was significant in the performance of the CKD-EPI formula. Upon subgroup analysing, all performance categories clearly improved as the BMI increased (Table 6). On dividing them into groups that were greater and less than 25kg/m<span class="elsevierStyleSup">2</span>, the difference was statistically significant. This is a possible explanation for the performance of the CKD-EPI formula in our study, which, as has already been mentioned, was to be expected because the original validation group included mostly obese individuals of Latino ethnicity (Native Americans and Hispanics)<span class="elsevierStyleSup">9</span>.</p><p class="elsevierStylePara">An interesting finding was the tendency of both formulae to overestimate the mGFR, contrarily to the United States and Europe. This phenomenon was also reported in Oriental populations and in South Africa, in which the bias (mGFR – eGFR) was reported as an average of -35ml/min/1.73m<span class="elsevierStyleSup">2</span> in the mGFR group greater than<span class="elsevierStyleSup">9</span> 90ml/min/1.73m<span class="elsevierStyleSup">2</span>. In our study, this overestimation decreased as the mGFR increased and in the mGFR range above 120ml/min/1.73m<span class="elsevierStyleSup">2</span> the sign was inverted and this was the only category in which the GFR was underestimated (average bias + 13.9). These data, although interesting, have a limited value due to the number of individuals. However, they set a CKD-EPI behaviour precedent in different mGFR ranges. If there was similar behaviour in lower mGFR, we would run the risk of underestimating CKD prevalence, which would be very important.</p><p class="elsevierStylePara">One relative limitation of this study is the number of individuals included, in spite of which the results were solid and significant and allowed validation of these estimation formulae. The second relative limitation is that we cannot know if the use of the formula will in some way impact on CKD detection since this study was not designed for CKD but rather required healthy individuals. Due to the tendency to overestimate the GFR, consistently observed in CKD-EPI and MDRD-IDMS, validation in groups with a lower GFR is essential in subsequent studies in order to avoid underdiagnosis of CKD. A third limitation is recruitment in a single hospital (INNSZ), which, although it receives patients and staff from all over the country, it prevents data obtained being generalised to a certain extent.</p><p class="elsevierStylePara"> </p><p class="elsevierStylePara"><span class="elsevierStyleBold">CONCLUSIONS</span></p><p class="elsevierStylePara"><span class="elsevierStyleBold"> </span></p><p class="elsevierStylePara">Estimation of GFR by CKD-EPI performed better than the MDRD-IDMS formula in healthy Mexican individuals with normal renal function. This is consistent with that reported in the literature, although to a lesser extent than was originally published. BMI had a significant impact on the performance of the CKD-EPI formula, and was significantly better in individuals with a BMI greater than 25kg/m<span class="elsevierStyleSup">2</span>. Both formulae overestimated the mGFR, unlike in African Americans and white individuals, but consistent with the behaviour in populations in Japan and South Africa. Due to the epidemiological implications, it is important to carry out a study on lower GFR and take into account the likely impact of BMI.</p><p class="elsevierStylePara"> </p><p class="elsevierStylePara"><span class="elsevierStyleBold">Conflicts of interest</span></p><p class="elsevierStylePara"> </p><p class="elsevierStylePara">The authors declare that they have no conflicts of interest related to the contents of this article.</p><p class="elsevierStylePara"><a href="grande/12538_16025_61172_en_t112538i.jpg" class="elsevierStyleCrossRefs"><img src="12538_16025_61172_en_t112538i.jpg" alt="General characteristics of the study population"></img></a></p><p class="elsevierStylePara">Table 1. General characteristics of the study population</p><p class="elsevierStylePara"><a href="grande/12538_16025_61173_en_t212538i.jpg" class="elsevierStyleCrossRefs"><img src="12538_16025_61173_en_t212538i.jpg" alt="Laboratory and anthropometric data "></img></a></p><p class="elsevierStylePara">Table 2. Laboratory and anthropometric data </p><p class="elsevierStylePara"><a href="grande/12538_16025_61174_en_t312538i_copy2.jpg" class="elsevierStyleCrossRefs"><img src="12538_16025_61174_en_t312538i_copy2.jpg" alt="Variables of performance of the estimation formulae versus the glomerular filtration rate measured with Tc99DTPA"></img></a></p><p class="elsevierStylePara">Table 3. Variables of performance of the estimation formulae versus the glomerular filtration rate measured with Tc99DTPA</p><p class="elsevierStylePara"><a href="grande/12538_16025_61175_en_t412538i.jpg" class="elsevierStyleCrossRefs"><img src="12538_16025_61175_en_t412538i.jpg" alt="Performance differences (bias and bias %) between CKD-EPI and MDRD-IDMS based on sex "></img></a></p><p class="elsevierStylePara">Table 4. Performance differences (bias and bias %) between CKD-EPI and MDRD-IDMS based on sex </p><p class="elsevierStylePara"><a href="grande/12538_16025_61176_en_t512538i.jpg" class="elsevierStyleCrossRefs"><img src="12538_16025_61176_en_t512538i.jpg" alt="Linear regression analysis for the CKD-EPI performance"></img></a></p><p class="elsevierStylePara">Table 5. Linear regression analysis for the CKD-EPI performance</p><p class="elsevierStylePara"><a href="grande/12538_16025_61177_en_t612538i.jpg" class="elsevierStyleCrossRefs"><img src="12538_16025_61177_en_t612538i.jpg" alt="Performance of the CKD-EPI formula in various body mass index levels"></img></a></p><p class="elsevierStylePara">Table 6. Performance of the CKD-EPI formula in various body mass index levels</p><p class="elsevierStylePara"><a href="grande/12538_16025_61178_en_f112538i3.jpg" class="elsevierStyleCrossRefs"><img src="12538_16025_61178_en_f112538i3.jpg" alt="Graph of correlation between the glomerular filtration rate measured with Tc99DTPA and the estimation formulae."></img></a></p><p class="elsevierStylePara">Figure 1. Graph of correlation between the glomerular filtration rate measured with Tc99DTPA and the estimation formulae.</p><p class="elsevierStylePara"><a href="grande/12538_16025_61179_en_f212538i3.jpg" class="elsevierStyleCrossRefs"><img src="12538_16025_61179_en_f212538i3.jpg" alt="Accuracy p(30) of CKD-EPI (A) and MDRD-IDMS (B)."></img></a></p><p class="elsevierStylePara">Figure 2. Accuracy p(30) of CKD-EPI (A) and MDRD-IDMS (B).</p><p class="elsevierStylePara"><a href="grande/12538_16025_61180_en_f312538i3.jpg" class="elsevierStyleCrossRefs"><img src="12538_16025_61180_en_f312538i3.jpg" alt="CKD-EPI performance in body mass index greater and less than 25."></img></a></p><p class="elsevierStylePara">Figure 3. CKD-EPI performance in body mass index greater and less than 25.</p>" "pdfFichero" => "P1-E574-S4691-A12538-EN.pdf" "tienePdf" => true "PalabrasClave" => array:2 [ "es" => array:5 [ 0 => array:4 [ "clase" => "keyword" "titulo" => "Palabras clave" "identificador" => "xpalclavsec437353" "palabras" => array:1 [ 0 => "Función renal normal" ] ] 1 => array:4 [ "clase" => "keyword" "titulo" => "Palabras clave" "identificador" => "xpalclavsec437355" "palabras" => array:1 [ 0 => "MDRD" ] ] 2 => array:4 [ "clase" => "keyword" "titulo" => "Palabras clave" "identificador" => "xpalclavsec437357" "palabras" => array:1 [ 0 => "CKD-EPI" ] ] 3 => array:4 [ "clase" => "keyword" "titulo" => "Palabras clave" "identificador" => "xpalclavsec437359" "palabras" => array:1 [ 0 => "Fórmulas de cálculo de la función renal" ] ] 4 => array:4 [ "clase" => "keyword" "titulo" => "Palabras clave" "identificador" => "xpalclavsec437361" "palabras" => array:1 [ 0 => "Índice de masa corporal" ] ] ] "en" => array:5 [ 0 => array:4 [ "clase" => "keyword" "titulo" => "Keywords" "identificador" => "xpalclavsec437354" "palabras" => array:1 [ 0 => "Normal renal function" ] ] 1 => array:4 [ "clase" => "keyword" "titulo" => "Keywords" "identificador" => "xpalclavsec437356" "palabras" => array:1 [ 0 => "MDRD" ] ] 2 => array:4 [ "clase" => "keyword" "titulo" => "Keywords" "identificador" => "xpalclavsec437358" "palabras" => array:1 [ 0 => "CKD-EPI" ] ] 3 => array:4 [ "clase" => "keyword" "titulo" => "Keywords" "identificador" => "xpalclavsec437360" "palabras" => array:1 [ 0 => "Formulae for calculating renal function" ] ] 4 => array:4 [ "clase" => "keyword" "titulo" => "Keywords" "identificador" => "xpalclavsec437362" "palabras" => array:1 [ 0 => "Body mass index" ] ] ] ] "tieneResumen" => true "resumen" => array:2 [ "es" => array:1 [ "resumen" => "<p class="elsevierStylePara"><span class="elsevierStyleBold">Antecedentes</span><span class="elsevierStyleBold">:</span> El funcionamiento de las fórmulas para la estimación de tasa de filtrado glomerular (TFG) CKD-EPI y MDRD en pacientes de origen hispano con función renal normal tiene pocos antecedentes y en México requiere validación. <span class="elsevierStyleBold">Material y métodos:</span> Se incluyeron individuos mexicanos, adultos y previamente sanos. Se recabaron variables clínicas y se determinó el nivel de creatinina sérica para calcular las fórmulas CKD-EPI y MDRD-IDMS. Este resultado fue comparado con el estándar de referencia (TFG medida con Tc<span class="elsevierStyleSup">99</span>DTPA). Se evaluaron otras variables clínicas que afectaran el funcionamiento de la fórmula CKD-EPI. <span class="elsevierStyleBold">Resultados:</span> Se incluyeron 97 individuos voluntarios sanos, 55 varones y 42 mujeres; edad promedio 35 años (18 a 73). La creatinina media fue de 0,76 mg/dl (± 0,18). El funcionamiento de CKD-EPI fue significativamente mejor que el de MDRD-IDMS en todas las comparaciones (sesgo, correlación y exactitud). La diferencia entre los sesgos de las fórmulas fue 6,08 ml/min/1,73 m<span class="elsevierStyleSup">2</span> (IC 95 % 2,58 a 9,58) (p < 0,001). Las personas con índice de masa corporal (IMC) mayor de 25 kg/m<span class="elsevierStyleSup">2</span> presentaron un mejor funcionamiento que el grupo con menor IMC (diferencia de medias 7,39 ml/min/1,73 m<span class="elsevierStyleSup">2</span>; IC 95 % 1,17 a 13,6; p < 0,02). Ambas fórmulas sobrestimaron la TFG. El IMC se asoció significativamente con el funcionamiento de la fórmula CKD-EPI (β 0,82; IC 95 % 0,085 a 1,56; p = 0,029). <span class="elsevierStyleBold">Conclusiones:</span> En individuos adultos mexicanos sanos la fórmula CKD-EPI predice mejor la TFGm que la fórmula MDRD-IDMS. El IMC se asocia de manera significativa al funcionamiento de la fórmula CKD-EPI, siendo mejor en aquellos con IMC superior a 25 kg/m<span class="elsevierStyleSup">2</span>. Ambas fórmulas sobrestiman la TFGm.</p>" ] "en" => array:1 [ "resumen" => "<p class="elsevierStylePara"><span class="elsevierStyleBold">Background:</span><span class="elsevierStyleBold"> </span>The performance of the CKD-EPI and MDRD formulae for estimating glomerular filtration rate (GFR) in patients of Hispanic origin with normal renal function has been poorly explored and requires validation in Mexico.<span class="elsevierStyleBold"> </span><span class="elsevierStyleBold">Material and method:</span> We included previously healthy Mexican adults. We obtained clinical variables and determined serum creatinine to calculate the CKD-EPI and MDRD-IDMS formulae. These results were compared with the gold standard (GFR measured by Tc<span class="elsevierStyleSup">99</span>DTPA). We evaluated other clinical variables that could affect the performance of the CKD-EPI formula.<span class="elsevierStyleBold"> </span><span class="elsevierStyleBold">Results:</span> A total of 97 healthy volunteers were included, 55 males and 42 females; the mean age was 35.8 years old (18 to 73). Mean creatinine was 0.76mg/dl (±0.18). CKD-EPI performance was significantly better than MDRD-IDMS in all comparisons (bias, correlation and accuracy). The bias difference between the formulae was 6.08ml/min/1.73m<span class="elsevierStyleSup">2</span> (95% CI 2.58 to 9.58) (<span class="elsevierStyleItalic">p</span><.001). Individuals with a body mass index (BMI) above 25kg/m<span class="elsevierStyleSup">2</span> displayed a better performance than the group with a lower BMI (difference of means 7.39ml/min/1.73m<span class="elsevierStyleSup">2</span>; 95% CI 1.17 to 13.6 <span class="elsevierStyleItalic">p</span><.02). Both formulae overestimated the GFR. BMI was significantly associated with the performance of the CKD-EPI formula (β 0.82; 95% CI 0.085 to 1.56 <span class="elsevierStyleItalic">p</span>=.029). <span class="elsevierStyleBold">Conclusions:</span> In healthy Mexican adults, the CKD-EPI formula is a better predictor of the mGFR than the MDRD-IDMS formula. BMI is significantly associated with the performance of the CKD-EPI formula and is better in those with a BMI greater than 25kg/m<span class="elsevierStyleSup">2</span>. Both formulae overestimate mGFR.</p>" ] ] "multimedia" => array:9 [ 0 => array:8 [ "identificador" => "fig1" "etiqueta" => "Tab. 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12538_16025_61172_en_t112538i.jpg" "Alto" => 673 "Ancho" => 1043 "Tamanyo" => 181156 ] ] "descripcion" => array:1 [ "en" => "General characteristics of the study population" ] ] 1 => array:8 [ "identificador" => "fig2" "etiqueta" => "Tab. 2" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12538_16025_61173_en_t212538i.jpg" "Alto" => 1055 "Ancho" => 1059 "Tamanyo" => 307005 ] ] "descripcion" => array:1 [ "en" => "Laboratory and anthropometric data" ] ] 2 => array:8 [ "identificador" => "fig3" "etiqueta" => "Tab. 3" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12538_16025_61174_en_t312538i_copy2.jpg" "Alto" => 449 "Ancho" => 2143 "Tamanyo" => 184989 ] ] "descripcion" => array:1 [ "en" => "Variables of performance of the estimation formulae versus the glomerular filtration rate measured with Tc99DTPA" ] ] 3 => array:8 [ "identificador" => "fig4" "etiqueta" => "Tab. 4" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12538_16025_61175_en_t412538i.jpg" "Alto" => 460 "Ancho" => 1043 "Tamanyo" => 142243 ] ] "descripcion" => array:1 [ "en" => "Performance differences (bias and bias %) between CKD-EPI and MDRD-IDMS based on sex" ] ] 4 => array:8 [ "identificador" => "fig5" "etiqueta" => "Tab. 5" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12538_16025_61176_en_t512538i.jpg" "Alto" => 279 "Ancho" => 2161 "Tamanyo" => 135103 ] ] "descripcion" => array:1 [ "en" => "Linear regression analysis for the CKD-EPI performance" ] ] 5 => array:8 [ "identificador" => "fig6" "etiqueta" => "Tab. 6" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12538_16025_61177_en_t612538i.jpg" "Alto" => 370 "Ancho" => 2149 "Tamanyo" => 154040 ] ] "descripcion" => array:1 [ "en" => "Performance of the CKD-EPI formula in various body mass index levels" ] ] 6 => array:8 [ "identificador" => "fig7" "etiqueta" => "Fig. 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12538_16025_61178_en_f112538i3.jpg" "Alto" => 894 "Ancho" => 2111 "Tamanyo" => 271257 ] ] "descripcion" => array:1 [ "en" => "Graph of correlation between the glomerular filtration rate measured with Tc99DTPA and the estimation formulae." ] ] 7 => array:8 [ "identificador" => "fig8" "etiqueta" => "Fig. 2" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12538_16025_61179_en_f212538i3.jpg" "Alto" => 658 "Ancho" => 2099 "Tamanyo" => 198533 ] ] "descripcion" => array:1 [ "en" => "Accuracy p(30) of CKD-EPI (A) and MDRD-IDMS (B)." ] ] 8 => array:8 [ "identificador" => "fig9" "etiqueta" => "Fig. 3" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "copyright" => "Elsevier España" "figura" => array:1 [ 0 => array:4 [ "imagen" => "12538_16025_61180_en_f312538i3.jpg" "Alto" => 520 "Ancho" => 1012 "Tamanyo" => 89032 ] ] "descripcion" => array:1 [ "en" => "CKD-EPI performance in body mass index greater and less than 25." ] ] ] "bibliografia" => array:2 [ "titulo" => "Bibliography" "seccion" => array:1 [ 0 => array:1 [ "bibliografiaReferencia" => array:15 [ 0 => array:3 [ "identificador" => "bib1" "etiqueta" => "1" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Johonson RJ, Feehally J, Jurgen F. Comprehensive Clinical Nephrology. 3rd ed. Philadelphia: Mosby; 2007." "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] 1 => array:3 [ "identificador" => "bib2" "etiqueta" => "2" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron 1976;16:31-41. <a href="http://www.ncbi.nlm.nih.gov/pubmed/1244564" target="_blank">[Pubmed]</a>" "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] 2 => array:3 [ "identificador" => "bib3" "etiqueta" => "3" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Madero M, Sarnak MJ. Creatinine-based formulae for estimation glomerular filtration rate: is it time to change to chronic kidney disease epidemiology collaboration equation? Curr Opin Nephrol Hypertens 2011;20:622-30. <a href="http://www.ncbi.nlm.nih.gov/pubmed/21941179" target="_blank">[Pubmed]</a>" "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] 3 => array:3 [ "identificador" => "bib4" "etiqueta" => "4" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Levey AS, Bosch JP, Lewis JB, Greene T, Rogers N, Roth D. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med 1999;130:461-70." "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] 4 => array:3 [ "identificador" => "bib5" "etiqueta" => "5" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Levey AS, Greene T, Kusek J, Beck G. A simplified equation to predict glomerular filtration rate from serum creatinine. J Am Soc Nephrol 2000;11:155A." "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] 5 => array:3 [ "identificador" => "bib6" "etiqueta" => "6" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Zuo L, Ma YC, Zhou YH, Wang M, Xu GB, Wang HY. Application of GFR-estimating equations in Chinese patients with chronic kidney disease. Am J Kidney Dis 2005;45(3):463-72. <a href="http://www.ncbi.nlm.nih.gov/pubmed/15754268" target="_blank">[Pubmed]</a>" "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] 6 => array:3 [ "identificador" => "bib7" "etiqueta" => "7" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Levey AS, Lesley A, Stevens MS, Zhang YL, Castro AF 3er, Feldman HI, et al. A new equation to estimate glomerular filtration rate. Ann Intern Med 2009;150:604-12. <a href="http://www.ncbi.nlm.nih.gov/pubmed/19414839" target="_blank">[Pubmed]</a>" "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] 7 => array:3 [ "identificador" => "bib8" "etiqueta" => "8" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Shafi T, Marsushita K, Selvin E, Sang Y, Aston BC, Inker LA, et al. Comparing the association of GFR estimated by CKD EPI and MDRD equations and mortality: the third national health and nutrition examination survey (NHANES III). BMC Nephrol 2012;13:42. <a href="http://www.ncbi.nlm.nih.gov/pubmed/22702805" target="_blank">[Pubmed]</a>" "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:1 [ "itemHostRev" => array:3 [ "pii" => "S152586101300039X" "estado" => "S300" "issn" => "15258610" ] ] ] ] ] ] ] 8 => array:3 [ "identificador" => "bib9" "etiqueta" => "9" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Stevens LA, Claybon MA, Shmid CH, Chen J, Horio M, Imai E, et al. Evaluation of the Chronic Kidney Disease Epidemiology Collaboration equation for estimating the glomerular filtration rate in multiple ethnicities. Kidney Int 2011;79:555-62. <a href="http://www.ncbi.nlm.nih.gov/pubmed/21107446" target="_blank">[Pubmed]</a>" "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] 9 => array:3 [ "identificador" => "bib10" "etiqueta" => "10" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Stevens LA, Schmind CH, Zhang YL, Coresh J, Manzi J, Landis R, et al Development and validation of GFR-estimating equations using diabetes, transplant and weight. Nephrol Dial Transplant 2010;25:449-57. <a href="http://www.ncbi.nlm.nih.gov/pubmed/19793928" target="_blank">[Pubmed]</a>" "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] 10 => array:3 [ "identificador" => "bib11" "etiqueta" => "11" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Myers GL, Miller WG, Coresh J, Fleming J, Greenberg N, Hostetter T, et al. Recommendations for improving serum creatinine measurement: A report of Laboratory Working Group of National Kidney Disease Education Program. Clin Chem 2006;52:5-18." "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] 11 => array:3 [ "identificador" => "bib12" "etiqueta" => "12" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Levey AS, Coresh J, Greene T, Stevens LA, Zhang YL, Hendriksen S, et al. Using standardized serum creatinine values in the modification of diet in renal disease study equation for estimating glomerular filtration rate. Ann Intern Med 2006;145:247-54. <a href="http://www.ncbi.nlm.nih.gov/pubmed/16908915" target="_blank">[Pubmed]</a>" "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] 12 => array:3 [ "identificador" => "bib13" "etiqueta" => "13" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Hernández Ocampo J, Torres Rosales A, Rodríguez Castellanos. Comparison of four methods for measuring glomerular filtration rate by inulin clearance in healthy individuals and patients with renal failure. Nefrologia 2010;30:324-30. <a href="http://www.ncbi.nlm.nih.gov/pubmed/20414326" target="_blank">[Pubmed]</a>" "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:1 [ "itemHostRev" => array:3 [ "pii" => "S1525861012003209" "estado" => "S300" "issn" => "15258610" ] ] ] ] ] ] ] 13 => array:3 [ "identificador" => "bib14" "etiqueta" => "14" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Stevens LA, Claybon MA, Shmid CH, Zhang YL, Beck GJ, Froissart M, et al Comparative performance of the CKD Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) Study equations for estimating GFR levels above 60 ml/min/1.73 m2. Am J Kidney Dis 2010;56:486-95. <a href="http://www.ncbi.nlm.nih.gov/pubmed/20557989" target="_blank">[Pubmed]</a>" "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] 14 => array:3 [ "identificador" => "bib15" "etiqueta" => "15" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Iker LA, Shmid CH, Tighiouart H, Eckfeldt JH, Feldman HI, Greene T, et al. Estimating glomerular filtration rate from serum creatinine and cystatin C. N Engl J Med 2012;367:20-9." "contribucion" => array:1 [ 0 => null ] "host" => array:1 [ 0 => null ] ] ] ] ] ] ] ] ] "idiomaDefecto" => "en" "url" => "/20132514/0000003400000005/v0_201502091605/X2013251414054601/v0_201502091605/en/main.assets" "Apartado" => array:4 [ "identificador" => "35441" "tipo" => "SECCION" "en" => array:2 [ "titulo" => "Originals" "idiomaDefecto" => true ] "idiomaDefecto" => "en" ] "PDF" => "https://static.elsevier.es/multimedia/20132514/0000003400000005/v0_201502091605/X2013251414054601/v0_201502091605/en/P1-E574-S4691-A12538-EN.pdf?idApp=UINPBA000064&text.app=https://revistanefrologia.com/" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/X2013251414054601?idApp=UINPBA000064" ]
| Year/Month | Html | Total | |
|---|---|---|---|
| 2024 November | 6 | 4 | 10 |
| 2024 October | 77 | 343 | 420 |
| 2024 September | 91 | 76 | 167 |
| 2024 August | 119 | 155 | 274 |
| 2024 July | 61 | 49 | 110 |
| 2024 June | 82 | 55 | 137 |
| 2024 May | 104 | 72 | 176 |
| 2024 April | 72 | 52 | 124 |
| 2024 March | 68 | 32 | 100 |
| 2024 February | 67 | 52 | 119 |
| 2024 January | 56 | 29 | 85 |
| 2023 December | 56 | 37 | 93 |
| 2023 November | 75 | 39 | 114 |
| 2023 October | 75 | 42 | 117 |
| 2023 September | 55 | 27 | 82 |
| 2023 August | 71 | 34 | 105 |
| 2023 July | 79 | 52 | 131 |
| 2023 June | 60 | 40 | 100 |
| 2023 May | 84 | 45 | 129 |
| 2023 April | 66 | 38 | 104 |
| 2023 March | 87 | 51 | 138 |
| 2023 February | 67 | 36 | 103 |
| 2023 January | 71 | 44 | 115 |
| 2022 December | 70 | 46 | 116 |
| 2022 November | 85 | 52 | 137 |
| 2022 October | 74 | 50 | 124 |
| 2022 September | 67 | 46 | 113 |
| 2022 August | 94 | 68 | 162 |
| 2022 July | 118 | 55 | 173 |
| 2022 June | 66 | 63 | 129 |
| 2022 May | 64 | 52 | 116 |
| 2022 April | 59 | 71 | 130 |
| 2022 March | 49 | 60 | 109 |
| 2022 February | 104 | 57 | 161 |
| 2022 January | 96 | 57 | 153 |
| 2021 December | 113 | 57 | 170 |
| 2021 November | 69 | 47 | 116 |
| 2021 October | 100 | 65 | 165 |
| 2021 September | 60 | 45 | 105 |
| 2021 August | 102 | 56 | 158 |
| 2021 July | 94 | 49 | 143 |
| 2021 June | 101 | 37 | 138 |
| 2021 May | 73 | 48 | 121 |
| 2021 April | 176 | 57 | 233 |
| 2021 March | 143 | 42 | 185 |
| 2021 February | 114 | 39 | 153 |
| 2021 January | 114 | 18 | 132 |
| 2020 December | 70 | 17 | 87 |
| 2020 November | 50 | 15 | 65 |
| 2020 October | 101 | 14 | 115 |
| 2020 September | 60 | 8 | 68 |
| 2020 August | 56 | 17 | 73 |
| 2020 July | 76 | 3 | 79 |
| 2020 June | 77 | 18 | 95 |
| 2020 May | 58 | 22 | 80 |
| 2020 April | 72 | 24 | 96 |
| 2020 March | 92 | 13 | 105 |
| 2020 February | 83 | 24 | 107 |
| 2020 January | 89 | 17 | 106 |
| 2019 December | 104 | 28 | 132 |
| 2019 November | 107 | 31 | 138 |
| 2019 October | 79 | 24 | 103 |
| 2019 September | 75 | 23 | 98 |
| 2019 August | 65 | 17 | 82 |
| 2019 July | 119 | 23 | 142 |
| 2019 June | 102 | 27 | 129 |
| 2019 May | 132 | 14 | 146 |
| 2019 April | 201 | 46 | 247 |
| 2019 March | 115 | 22 | 137 |
| 2019 February | 68 | 21 | 89 |
| 2019 January | 93 | 10 | 103 |
| 2018 December | 225 | 44 | 269 |
| 2018 November | 169 | 16 | 185 |
| 2018 October | 197 | 25 | 222 |
| 2018 September | 236 | 24 | 260 |
| 2018 August | 123 | 17 | 140 |
| 2018 July | 120 | 15 | 135 |
| 2018 June | 112 | 13 | 125 |
| 2018 May | 136 | 16 | 152 |
| 2018 April | 107 | 11 | 118 |
| 2018 March | 104 | 12 | 116 |
| 2018 February | 84 | 15 | 99 |
| 2018 January | 50 | 8 | 58 |
| 2017 December | 69 | 13 | 82 |
| 2017 November | 91 | 11 | 102 |
| 2017 October | 58 | 11 | 69 |
| 2017 September | 76 | 10 | 86 |
| 2017 August | 107 | 22 | 129 |
| 2017 July | 112 | 11 | 123 |
| 2017 June | 134 | 13 | 147 |
| 2017 May | 137 | 13 | 150 |
| 2017 April | 131 | 17 | 148 |
| 2017 March | 112 | 22 | 134 |
| 2017 February | 165 | 17 | 182 |
| 2017 January | 73 | 11 | 84 |
| 2016 December | 132 | 16 | 148 |
| 2016 November | 134 | 27 | 161 |
| 2016 October | 197 | 19 | 216 |
| 2016 September | 200 | 10 | 210 |
| 2016 August | 317 | 9 | 326 |
| 2016 July | 239 | 10 | 249 |
| 2016 June | 187 | 0 | 187 |
| 2016 May | 223 | 0 | 223 |
| 2016 April | 195 | 0 | 195 |
| 2016 March | 145 | 0 | 145 |
| 2016 February | 171 | 0 | 171 |
| 2016 January | 168 | 0 | 168 |
| 2015 December | 145 | 0 | 145 |
| 2015 November | 123 | 0 | 123 |
| 2015 October | 144 | 0 | 144 |
| 2015 September | 101 | 0 | 101 |
| 2015 August | 98 | 0 | 98 |
| 2015 July | 144 | 0 | 144 |
| 2015 June | 61 | 0 | 61 |
| 2015 May | 77 | 0 | 77 |
| 2015 April | 10 | 0 | 10 |
Show all
