Dietary intake of non-dialysis chronic kidney disease patients: the PROGREDIR study. A cross-sectional study.

BACKGROUND: Despite evidence that diet is very important in relation to chronic kidney disease (CKD) progression, studies in this field are scarce and have focused only on some specific nutrients. We evaluated the energy, macronutrient and micronutrient intakes and dietary patterns of non-dialysis CKD participants in the PROGREDIR study. DESIGN AND SETTING: Cross-sectional study; CKD cohort, São Paulo, Brazil. METHODS: Baseline data on 454 participants in the PROGREDIR study were analyzed. Dietary intake was evaluated through a food frequency questionnaire. Dietary patterns were derived through principal component analysis. Energy and protein intakes were compared with National Kidney Foundation recommendations. Linear regression analysis was performed between energy and nutrient intakes and estimated glomerular filtration rate (eGFR), and between sociodemographic and clinical variables and dietary patterns. RESULTS: Median energy and protein intakes were 25.0 kcal/kg and 1.1 g/kg, respectively. In linear regression, protein intake (ß = -3.67; P = 0.07) was related to eGFR. Three dietary patterns (snack, mixed and traditional) were retained. The snack pattern was directly associated with male gender (ß = 0.27; P = 0.006) and inversely with diabetes (ß = -0.23; P = 0.02). The traditional pattern was directly associated with male gender (ß = 0.27; P = 0.007) and schooling (ß = 0.40; P < 0.001) and inversely with age (ß = -0.01; P = 0.001) and hypertension (ß = -0.34; P = 0.05). CONCLUSIONS: We identified low energy and high protein intake in this population. Protein intake was inversely related to eGFR. Dietary patterns were associated with age, gender, schooling level, hypertension and diabetes.

Chronic kidney disease - determinants of progression and cardiovascular risk. PROGREDIR cohort study: design and methods.

CONTEXT AND OBJECTIVE:: Chronic kidney disease (CKD) has become an important public health issue. The socioeconomic burden of renal replacement therapy (RRT) is very high, as is CKD-related cardiovascular mortality and morbidity. Preventive and therapeutic measures only have modest impact and more research is needed. Few cohort studies have been conducted on populations with CKD. Our aim was to establish a cohort that would include more advanced forms of CKD (stages 3 and 4). Data collection was focused on renal and cardiovascular parameters. DESIGN AND SETTING:: Prospective cohort study; São Paulo, Brazil. METHODS:: Recruitment took place in Hospital das Clínicas, São Paulo, from March 2012 to December 2013. Data relating to medical history, food-frequency questionnaire, anthropometry, laboratory work-up, calcium score, echocardiography, carotid intimal-medial thickness, pulse-wave velocity, retinography and heart rate variability were collected. A biobank including serum, plasma, post-oral glucose tolerance test serum and plasma, urine (morning and 24-hour urine) and DNA was established. RESULTS:: 454 participants (60% men and 50% diabetics) of mean age 68 years were enrolled. Their mean estimated glomerular filtration rate-CKD Epidemiology Collaboration was 38 ml/min/1.73 m2. Follow-up is ongoing and the main outcomes are the start of RRT, cardiovascular events and death. CONCLUSIONS:: The PROGREDIR cohort is a promising prospective study that will allow better understanding of CKD determinants and validation of candidate biomarkers for the risks of CKD progression and mortality.

Chronic kidney disease - determinants of progression and cardiovascular risk. PROGREDIR cohort study: design and methods / Doença renal crônica - determinantes de progressão e risco cardiovascular. Coorte PROGREDIR: desenho de estudo e métodos

ABSTRACT CONTEXT AND OBJECTIVE: Chronic kidney disease (CKD) has become an important public health issue. The socioeconomic burden of renal replacement therapy (RRT) is very high, as is CKD-related cardiovascular mortality and morbidity. Preventive and therapeutic measures only have modest impact and more research is needed. Few cohort studies have been conducted on populations with CKD. Our aim was to establish a cohort that would include more advanced forms of CKD (stages 3 and 4). Data collection was focused on renal and cardiovascular parameters. DESIGN AND SETTING: Prospective cohort study; São Paulo, Brazil. METHODS: Recruitment took place in Hospital das Clínicas, São Paulo, from March 2012 to December 2013. Data relating to medical history, food-frequency questionnaire, anthropometry, laboratory work-up, calcium score, echocardiography, carotid intimal-medial thickness, pulse-wave velocity, retinography and heart rate variability were collected. A biobank including serum, plasma, post-oral glucose tolerance test serum and plasma, urine (morning and 24-hour urine) and DNA was established. RESULTS: 454 participants (60% men and 50% diabetics) of mean age 68 years were enrolled. Their mean estimated glomerular filtration rate-CKD Epidemiology Collaboration was 38 ml/min/1.73 m2. Follow-up is ongoing and the main outcomes are the start of RRT, cardiovascular events and death. CONCLUSIONS: The PROGREDIR cohort is a promising prospective study that will allow better understanding of CKD determinants and validation of candidate biomarkers for the risks of CKD progression and mortality.

RESUMO CONTEXTO E OBJETIVO: A doença renal crônica (DRC) tornou-se um problema de saúde pública. A carga socioeconômica da terapia renal substitutiva é muito elevada, assim como a morbimortalidade cardiovascular associada à DRC. Medidas terapêuticas e preventivas têm impacto parcial e novos estudos são necessários. Há poucos estudos de coorte em populações com DRC. Nosso objetivo foi criar uma coorte que contemplasse formas mais avançadas de DRC (estágios 3 e 4). A coleta de dados foi centrada em parâmetros renais e cardiovasculares. TIPO DE ESTUDO E LOCAL: Estudo de coorte prospectivo; São Paulo, Brasil. MÉTODOS: O recrutamento ocorreu entre março de 2012 e dezembro de 2013, no Hospital das Clínicas, em São Paulo. Foram coletados dados de história médica, questionário de frequência alimentar, antropometria, exames laboratoriais, escore de cálcio, ecocardiografia, espessura de camada médio-intimal de carótidas, velocidade de onda de pulso, retinografia e variabilidade de frequência cardíaca. Um biobanco incluindo soro, plasma, soro e plasma pós-teste oral de tolerância à glicose, urina (manhã e 24 horas) e DNA foi estabelecido. RESULTADOS: 454 participantes (60% homens e 50% diabéticos) com idade média de 68 anos foram recrutados. A taxa média de filtração glomerular estimada-Colaboração da Epidemiologia para DRC foi de 38,4 ml/min/1,73 m2. O seguimento está em andamento e os desfechos principais são: início de terapia renal substitutiva, eventos cardiovasculares e óbito. CONCLUSÃO: A coorte PROGREDIR é um estudo prospectivo promissor que permitirá melhor compreensão dos determinantes de DRC e a validação de biomarcadores candidatos para o risco de progressão de DRC e de mortalidade.

Urinary Retinol-Binding Protein: Relationship to Renal Function and Cardiovascular Risk Factors in Chronic Kidney Disease.

The role of urinary retinol-binding protein (RBP) as a biomarker of CKD in proximal tubular diseases, glomerulopathies and in transplantation is well established. However, whether urinary RBP is also a biomarker of renal damage and CKD progression in general CKD is not known. In this study, we evaluated the association of urinary RBP with renal function and cardiovascular risk factors in the baseline data of the Progredir Study, a CKD cohort in Sao Paulo, Brazil, comprising 454 participants with stages 3 and 4 CKD. In univariate analysis, urinary RBP was inversely related to estimated glomerular filtration rate (CKD-EPI eGFR) and several cardiovascular risk factors. After adjustments, however, only CKD-EPI eGFR, albuminuria, systolic blood pressure, anemia, acidosis, and left atrium diameter remained significantly related to urinary RBP. The inverse relationship of eGFR to urinary RBP (ß-0.02 ± 95CI -0.02; -0.01, p<0.0001 for adjusted model) remained in all strata of albuminuria, even after adjustments: in normoalbuminuria (ß-0.008 ± 95CI (-0.02; -0.001, p = 0.03), in microalbuminuria (ß-0.02 ± 95CI (-0.03; -0.02, p<0,0001) and in macroalbuminuria (ß-0.02 ± 95CI (-0.03; -0.01, p<0,0001). Lastly, urinary RBP was able to significantly increase the accuracy of a logistic regression model (adjusted for sex, age, SBP, diabetes and albuminuria) in diagnosing eGFR<35 ml/min/1.73m2 (AUC 0,77, 95%CI 0,72-0,81 versus AUC 0,71, 95%CI 0,65-0,75, respectively; p = 0,05). Our results suggest that urinary RBP is significantly associated to renal function in CKD in general, a finding that expands the interest in this biomarker beyond the context of proximal tubulopathies, glomerulopathies or transplantation. Urinary RBP should be further explored as a predictive marker of CKD progression.

RBP urinária e sérica: associação com doença renal crônica e fatores de risco cardiovascular / Urinary and serum RBP: relationship with chronic kidney disease and cardiovascular risk factors

A RBP urinária tem seu papel bem definido como marcador de progressão de doença renal em tubulopatias, em glomerulopatias e em pacientes transplantados. No entanto, seu papel em DRC lato senso foi pouco estudado. Por sua vez, a dosagem de RBP sérica, caracterizada recentemente como biomarcador de resistência insulínica, também não teve seu papel esclarecido em população portadora de DRC. O objetivo do presente estudo foi avaliar a relação entre a RBP (urinária e sérica) e a função renal, assim como sua relação com fatores de risco cardiovascular em população de DRC. Para tanto, foram analisados os dados da linha de base da Coorte PROGREDIR, constituída por 454 participantes portadores de DRC, oriundos do Hospital das Clínicas, São Paulo. Inicialmente, além de estar inversamente relacionada às medidas de depuração de creatinina, a RBP urinária mostrou-se relacionada a diversos fatores de risco cardiovascular e variáveis associadas à função renal, como proteinúria, metabolismo ósseo, anemia, acidose, albumina, RPB sérica, Hb glicada, HOMA, lípides, velocidade de onda de pulso (VOP), átrio esquerdo (ECO AE), diâmetro diastólico do ventrículo esquerdo (ECO-Ddve), diâmetro sistólico do ventrículo esquerdo (ECO-Dsve) e fração de ejeção (ECO-Fe). Entretanto, após diversos modelos de regressão, permaneceram como variáveis independentemente associadas à RBP urinária a função renal, a pressão arterial sistólica, a albuminúria, a acidose e a medida do AE. Esse resultado se manteve quando o modelo foi repetido mediante estratificação por albuminúria, sugerindo que mesmo em população normoalbuminúrica a RBP urinária correlacione-se inversamente com função renal. Além disso, a relação inversa de RBP urinária com dilatação cardíaca sugere que, em população com DRC já estabelecida, a RBP urinária possa ter um papel em identificar mecanismos etiológicos, possivelmente por distinguir mecanismos hemodinâmicos daqueles onde há uma patologia renal intrínseca. Por sua vez, a...

The role of urinary RBP as a biomarker of tubular injury and CKD progression in tubulopathies, glomerulopathies and in transplantation is well established. However, its role in CKD is less studied. In addition, serum RBP has been recently characterized as an insulin resistance marker, but controversial results have been shown. The aim of the study was to evaluate the association of both urinary RBP and serum RBP with kidney function and other variables related to the uremic syndrome and cardiovascular risk in a CKD population. We used the baseline data from the PROGREDIR Cohort, which comprehends 454 participants with CKD, recruited from Hospital das Clínicas, Sao Paulo. In univariate analysis, urinary RBP was inversely related to renal function. In addition, it was also related to albuminuria, SBP, anemia, mineral metabolism, acidosis, albumin, serum RPB, glycated hemoglobin, HOMA, lipids, pulse-wave velocity, left atrium diameter, left ventricle diastolic diameter, left ventricle systolic diameter and ejection fraction. However, in the multivariate analysis, only SBP, albuminuria, acidosis, left atrium diameter and renal function remained significantly associated to urinary RBP. After stratification for albuminuria levels, the same relationship was observed, suggesting that even in the normoalbuminuric population urinary RBP is significantly related to renal function. Interestingly, the inverse association between urinary RBP and cardiac dilation suggests that urinary RBP may play a role in identifying mechanisms related to CKD, by differentiating vascular/cardio-renal conditions versus more intrinsic kidney disease and possibly tubule-interstitial fibrosis. The serum RBP was positively related to renal function, triglycerides, albumin, age and potassium, but not to measurements of carbohydrate metabolism. No relationship between urinary or serum RBP and coronary calcification or carotid thickness was found. Our results suggest that urinary...