Background: Low protein diet is one of the treatments for patients with chronic kidney disease during the pre-dialysis period. Studies about this subject have been published for more than 20 years, but the conclusions about its effect and the most appropriate composition are not clear. A low-protein diet is recommended for some patients at the Nephrology Clinic of General University Hospital. These patients are educated and re- educated by a nutrition therapist who also controls their food intake through a food diary. Objectives: To evaluate the effect of low-protein diet on the progression of chronic kidney disease in our conditions and to compare the results with the control group. Furthermore, to evaluate the nutritional status of these patients and the influence of the diet on it. Last but not least, describe a set of patients coming to education about low-protein diet. Methods: The input data was retrospectively retrieved from the medical records of patients who attended medical checks at the Nephrology Clinic of General University Hospital between 10/2016 and 3/2018. A group of 15 patients with a low-protein diet was compared with a control group of 15 patients who did not receive low-protein diet education. The main data collected was year of birth, estimated GFR, urea, creatinine, albumin,...

La progression de l'incidence de l'insuffisance rénale chronique dans le monde nécessite d'améliorer les mesures visant à ralentir sa progression et son évolution vers l'insuffisance rénale terminale. Le régime pauvre en protéines ou la prévention des épisodes d'ischémie- reperfusion appartiennent à ces mesures de néphroprotection mais leur bénéfice n'est qu'incomplètement compris. Le rein étant un des organes les plus vascularisé, rapporté à son poids, l'évaluation concomitante de la perfusion rénale ([15O]H2O), du métabolisme oxydatif ([11C]acetate) puis du contenu tissulaire en oxygène (BOLD-IRM) est fondamentale dans la mesure où ces trois mesures ne sont pas corrélées de manière linéaire. La TEP-IRM, appareil hybride combinant les fonctionnalités de la TEP et de l'IRM, permet une évaluation concomitante de ces trois paramètres de manière non invasive et sur rein isolé ce qui permet de l'utiliser en recherche clinique pour l'évaluation de l'effet de différentes interventions. Les régimes pauvres en protéines ont démontré qu'ils permettaient un ralentissement du déclin de la fonction rénale mais le mécanisme à l'origine de cet effet bénéfique n'est pas connu. Nous avons démontré que le contenu en AGE (Advanced Glycation End Products ou protéines modifiées) d'une charge protéique était responsable de la mobilisation de la réserve fonctionnelle rénale avec une augmentation de la perfusion et du métabolisme oxydatif plus importants après une charge protéique riche en AGE par rapport à une charge protéique pauvre en AGE. Nos résultats permettent de s'interroger sur l'intérêt d'une alimentation pauvre en AGE pour les insuffisants rénaux chroniques au-delà d'une restriction protéique pure. La prévention des épisodes d'ischémie- reperfusion est également particulièrement importante dans le cadre de la néphroprotection alors que la revascularisation d'une sténose de l'artère rénale s'accompagne obligatoirement de lésions de reperfusion. L'utilisation de la ciclosporine avant la dilatation d'une sténose de l'artère rénale dans le cadre d'un pré conditionnement a permis de réduire les lésions rénales chez la souris mais ce bénéfice clinique n'a pas été démontré chez l'homme. L'étude CICLOSAAR qui a pour but d'évaluer le bénéfice d'un pré conditionnement par la ciclosporine A avant dilatation d'une sténose de l'artère rénale sur des paramètres fonctionnels rénaux (perfusion, métabolisme oxydatif et contenu tissulaire en oxygène) est en cours. Dans un second temps et afin d'améliorer l'applicabilité clinique de ces techniques d'imagerie fonctionnelle, nous avons démontré que l'acétate, qui était jusque-là utilisé comme un marqueur de métabolisme oxydatif, pouvait également être utilisé comme un marqueur de perfusion rénale grâce à la modélisation de son uptake par le rein. Au total, la TEP- IRM est un outil fondamental pour l'évaluation des paramètres fonctionnels rénaux de manière non invasive chez l'humain. La mise en évidence de l'impact du contenu en AGE sur la perfusion et le métabolisme rénal devrait permettre d'affiner nos conseils diététiques aux insuffisants rénaux pour prévenir la progression de la maladie vers l'insuffisance rénale terminale. L'étude CicloSAAR actuellement en cours devrait permettre d'améliorer les mesures mises en oeuvre pour protéger le rein des lésions de reperfusion après dilatation d'une sténose de l'artère rénale. Enfin, nos résultats sur la forte corrélation entre les données de perfusion en acétate et en eau devraient permettre d'utiliser ce traceur pour obtenir la perfusion et le métabolisme oxydatif à l'issue d'une seule injection de radio-traceur et renforcer l'applicabilité clinique de ces techniques / The increase in the incidence of chronic renal failure worldwide requires improvements in measures to slow its progression to end-stage renal failure. The low-protein diet or the prevention of episodes of ischemia-reperfusion belong to these measures of nephroprotection but their benefit is only incompletely understood. The kidney is one of the most vascularized organs, compared to its weight, the concomitant evaluation of renal perfusion ([15O] H2O), oxidative metabolism ([11C] acetate) and tissue content in oxygen (BOLD-IRM) is fundamental in that these three measures are not linearly correlated. PETMRI, a hybrid device combining the functionalities of PET and MRI, allows a concomitant evaluation of these three parameters in a non-invasive and isolated kidney way which allows to use it in clinical research for the evaluation of the effect of different interventions. Low-protein diets have been shown to slow down the decline in renal function, but the mechanism behind this beneficial effect is not known. We have demonstrated that the AGE (Advanced Glycation End Products) content of a protein load is responsible for the mobilization of the renal functional reserve with an increase in perfusion and oxidative metabolism after a high- AGE high- protein compared to a low- AGE high- protein load. Our results make it possible to question the interest of a low-AGE diet for chronic renal insufficiency beyond a pure protein restriction. The prevention of episodes of ischemia reperfusion is also particularly important in the context of nephroprotection, whereas the revascularization of a stenosis of the renal artery is necessarily accompanied by reperfusion injury. Use of ciclosporin prior to dilation of renal artery stenosis in pre-conditioning reduced renal damage in mice, but this clinical benefit has not been demonstrated in humans. The CICLOSAAR study, which aims to evaluate the benefit of pre-conditioning with ciclosporin before dilation of renal artery stenosis with renal functional parameters (perfusion, oxidative metabolism and tissue oxygen content) is in progress. In a second step and to improve the clinical applicability of these functional imaging techniques, we have shown that acetate, which was previously used as a marker of oxidative metabolism, could also be used as a marker of renal perfusion through the modeling of its uptake by the kidney. In total, PET-MRI is a fundamental tool for the evaluation of renal functional parameters in a non-invasive way in humans. Demonstrating the impact of the AGE content of a protein load on perfusion and renal metabolism should help refine our dietary advice to patients with chronic kidney disease to prevent progression of the disease to end-stage renal failure. The current CicloSAAR study is expected to improve the measures implemented to protect the kidney from reperfusion injury after dilatation of renal artery stenosis. Finally, our results on the strong correlation between acetate and water perfusion data should allow this tracer to be used to obtain perfusion and oxidative metabolism after a single radio tracer injection and reinforce clinical applicability of these techniques

Die Entwicklung eines Embryos und Fetus beeinflusst die Anfälligkeit für kardiovaskuläre Erkrankungen im weiteren Verlauf des Lebens entscheidend. Zugrundeliegende Mechanismen sind jedoch weitestgehend unbekannt. Unter Zuhilfenahme eines neuen Mausmodells für intrauterine kardiale Wachstumsretardierung zielt die vorliegende Dissertation auf die Identifikation adaptiver Wachstumsmechanismen ab, welche die Anpassung der Organgröße und die Aufrechterhaltung einer normalen Herzfunktion ermöglichen. Vielzählige Gene des Aminosäure (AS)-Metabolismus und der Proteinhomeostase zeigten eine vermehrte Expression in neugeborenen Mausherzen nach gestörter Embryonalentwicklung. Es wurde angenommen, dass sowohl die AS-Verfügbarkeit als auch die Aktivität der mechanistic target of rapamycin (mTOR) Signalkaskade entscheidend für eine normale Herzentwicklung und postnatales kompensatorisches Wachstum sind. Der mTOR Komplex 1 (mTORC1) wurde in prä- und perinatalen Mäusen mittels Rapamycin-Behandlung trächtiger Weibchen inhibiert. Die Auswirkungen einer prä- und postnatalen AS-Restriktion wurden anhand einer Niedrigproteindiät untersucht. Rapamycin-behandelte Neugeborene zeichneten sich durch vermindertes Gesamtwachstum sowie Entwicklungsverzögerung aus. Dabei war die kardiale Entwicklung besonders betroffen. Kardiale Proliferationsraten waren nicht verändert, die verminderte Herzgröße wurde jedoch auf eine verringerte Kardiomyozytengröße sowie eine erhöhte Apoptoserate zurückgeführt. Die intrauterine AS-Restriktion wurde überraschend gut von den Mausherzen toleriert. Zusammenfassend konnte gezeigt werden, dass die mTOR Signalkaskade essentiell für eine normale Herzentwicklung sowie kompensatorisches kardiales Wachstum ist. Darüber hinaus stellt die pränatale Rapamycin-Behandlung möglicherweise ein neues Modell der intrauterinen Wachstumsretardierung dar, welches Untersuchungen von Programmierungs-Mechanismen vor allem während der fötalen und perinatalen Herzentwicklung ermöglicht. / Intrauterine development influences the susceptibility to cardiovascular disease in adulthood, although the underlying molecular mechanisms are vastly unknown. Utilizing a new mouse model of impaired heart development, this thesis aims at identifying pre- and postnatal adaptive growth mechanisms to restore organ size and allow normal cardiac function. Unbiased functional annotation of genes differentially expressed in neonatal hearts after impaired intrauterine development revealed numerous gene clusters involved in amino acid (AA) metabolism and protein homeostasis. It was hypothesized that both AA availability and mechanistic target of rapamycin (mTOR) pathway activation are crucial for normal heart development and compensatory cardiac growth. mTOR complex 1 (mTORC1) was inhibited in fetal and neonatal mice by rapamycin treatment of pregnant dams. The effects of pre- and postnatal AA restriction were studied by feeding dams a low protein diet (LPD) throughout pregnancy and keeping the offspring on LPD postnatally. Rapamycin treated neonates were characterized by overall growth restriction and developmental delay, where cardiac development was especially affected (reduction of heart size, weight and heart weight to body weight ratio, severe thinning and noncompaction of the ventricular myocardium as well as immature myocardial morphology). While proliferation rates were unaffected, the reduced neonatal heart size was attributed to decreased cardiomyocyte size and increased apoptosis. Strikingly, the murine heart appeared to be surprisingly resistant to intrauterine AA restriction. In conclusion, the data revealed mTOR being essential for normal as well as compensatory cardiac development and growth. Moreover, prenatal rapamycin treatment might represent a new model of intrauterine growth restriction, which potentially allows the investigation of developmental programming mechanisms within the heart particularly in the fetal and neonatal phase of development.

Introdução: A maioria dos distúrbios metabólicos presentes na doença renal crônica (DRC) resulta, principalmente, do acúmulo de produtos do metabolismo do nitrogênio presentes nos alimentos ricos em proteínas. Dietas hiperprotéicas estão associadas à hiperperfusão, hipertensão e hiperfiltração glomerular e, conseqüentemente, à progressão da DRC. A dietoterapia tem um papel importante no tratamento da DRC, consistindo, principalmente, na redução da oferta diária de proteínas. Objetivo: Verificar o efeito da intervenção dietoterápica no estado nutricional, na progressão da doença renal e nos parâmetros inflamatórios, lipídicos, estado oxidativo e níveis séricos de potássio, de pacientes com insuficiência renal crônica em fase pré-dialítica. Pacientes e Métodos: Foi realizado um estudo prospectivo randomizado controlado cruzado em pacientes com DRC Estágio IV, em atendimento ambulatorial. O estudo constou de dois grupos de pacientes com DRC em fase pré-dialítica, que seguiram dois esquemas dietoterápicos diferentes, durante seis semanas: 21 pacientes iniciaram com prescrição de dieta normoprotéica (1 g/kg/dia) e 20 com prescrição de dieta hipoprotéica (0,6 g/kg/dia). Após esse período, os grupos inverteram as dietas. Foram avaliados parâmetros dietéticos, bioquímicos e antropométricos no momento basal e após seis e doze semanas. Os dados foram analisados segundo a intenção de tratamento na análise de crossover e por adesão à dieta hipoprotéica. Utilizaramse testes ANOVA para medidas repetidas e correlação de Spearman. O nível de significância adotado foi o de P < 0,05. Resultados: Foram avaliados 41 pacientes. Apenas um paciente (2,4%) foi considerado desnutrido e 28 (68%) apresentaram sobrepeso ou obesidade. Dezessete pacientes (41,5%) foram considerados inflamados, de acordo com o nível de PCR. Houve baixa adesão à dieta hipoprotéica.Não se observou prejuízo no estado nutricional dos pacientes durante o seguimento de prescrição de dieta hipoprotéica. Nos pacientes não inflamados observou-se melhora nos parâmetros de função renal, ao passo que, nos inflamados, estes parâmetros apresentaram deterioração. Observaram-se correlações negativas significativas entre os níveis séricos de HDL-colesterol e creatinina; HDL-colesterol e IMC; e correlações positivas significativas entre colesterol-total e uréia; LDL-colesterol e uréia; PNA/kg e HDL, triglicerídios e tirosina; triglicerídios e fibrinogênio; triglicerídios e creatinina; uréia e albumina. Conclusões: A adesão à dieta hipoprotéica foi muito pequena. A dieta hipoprotéica não interferiu no estado nutricional. A presença de inflamação influenciou, negativamente, a evolução da função renal. O perfil lipídico esteve relacionado ao estado nutricional, aos fatores de progressão da DRC e à inflamação; a lipoperoxidação esteve associada aos níveis séricos de albumina. / Background: Most metabolic disorders presented by patients with chronic renal disease (CRD) are mainly a result of accumulation of products of nitrogen metabolism, present in protein rich foods. High protein diets are associated with hyperperfusion, hypertension and hyperfiltration of the glomeruli and, as a consequence, may accelerate the progression of CRF. Nutritional therapy plays an important role in CRF treatment, consisting mainly in reduction of daily protein intake. Objective: To verify the effect of nutrition therapy intervention on nutritional status, on renal disease progression and on inflammatory and lipid parameters, oxidative status and potassium serum levels in patients with chronic renal insufficiency in the pre dialysis period. Patients and Methods: A crossover controlled prospective, randomized study in outpatients with stage IV CRD was carried out. The study consisted in the follow up of two groups of patients with CRD in the pre dialysis period. By randomization 21 patients were started on a 1g protein/kg/day diet prescription and 20 patients on low protein diet (0.6g/kg/day). After six weeks diets were reversed between the two groups and followed for another six week period. Dietetic, biochemical and anthropometric parameters were assessed at baseline and after 6 and 12 weeks. Data were analyzed according to the intention to treat approach in the crossover analysis and by adherence to the low protein diet. ANOVA for repeated measures and Spearman´s correlation tests were used for statistical analysis. The significance level adopted was P < 0.05. Results: 41 patients were evaluated. Only one patient (2.4%) was considered undernourished and 28 patients (68%) presented either over weighted or obese. Seventeen patients (41.5%) were considered inflamed according to the level of C reactive protein (CRP). Low adherence to the low protein diet was observed. Damage on nutritional status was not observed on low protein diet. In non-inflamed patients an improvement on renal function parameters was observed, whereas in the inflamed ones these parameters presented deterioration. Significant negative correlations between HDL-cholesterol serum levels and creatinine, HDL-cholesterol and body mass index (BMI) were observed. Significant positive correlations were observed between total cholesterol and urea, LDL-cholesterol and urea, PNA/kg and HDL, triglycerides and tyrosine, triglycerides and fibrinogen, triglycerides and creatinine, urea and albumin. Conclusions: Patients adhered poorly to low protein diets. Low protein diet did not influence the nutritional status. Presence of inflammation influenced negatively the evolution of renal function. The lipid profile was related to the nutritional status, to the progression factors of CRF and to inflammation. Lipoperoxidation was associated to serum levels of albumin.

Introdução: A maioria dos distúrbios metabólicos presentes na doença renal crônica (DRC) resulta, principalmente, do acúmulo de produtos do metabolismo do nitrogênio presentes nos alimentos ricos em proteínas. Dietas hiperprotéicas estão associadas à hiperperfusão, hipertensão e hiperfiltração glomerular e, conseqüentemente, à progressão da DRC. A dietoterapia tem um papel importante no tratamento da DRC, consistindo, principalmente, na redução da oferta diária de proteínas. Objetivo: Verificar o efeito da intervenção dietoterápica no estado nutricional, na progressão da doença renal e nos parâmetros inflamatórios, lipídicos, estado oxidativo e níveis séricos de potássio, de pacientes com insuficiência renal crônica em fase pré-dialítica. Pacientes e Métodos: Foi realizado um estudo prospectivo randomizado controlado cruzado em pacientes com DRC Estágio IV, em atendimento ambulatorial. O estudo constou de dois grupos de pacientes com DRC em fase pré-dialítica, que seguiram dois esquemas dietoterápicos diferentes, durante seis semanas: 21 pacientes iniciaram com prescrição de dieta normoprotéica (1 g/kg/dia) e 20 com prescrição de dieta hipoprotéica (0,6 g/kg/dia). Após esse período, os grupos inverteram as dietas. Foram avaliados parâmetros dietéticos, bioquímicos e antropométricos no momento basal e após seis e doze semanas. Os dados foram analisados segundo a intenção de tratamento na análise de crossover e por adesão à dieta hipoprotéica. Utilizaramse testes ANOVA para medidas repetidas e correlação de Spearman. O nível de significância adotado foi o de P < 0,05. Resultados: Foram avaliados 41 pacientes. Apenas um paciente (2,4%) foi considerado desnutrido e 28 (68%) apresentaram sobrepeso ou obesidade. Dezessete pacientes (41,5%) foram considerados inflamados, de acordo com o nível de PCR. Houve baixa adesão à dieta hipoprotéica.Não se observou prejuízo no estado nutricional dos pacientes durante o seguimento de prescrição de dieta hipoprotéica. Nos pacientes não inflamados observou-se melhora nos parâmetros de função renal, ao passo que, nos inflamados, estes parâmetros apresentaram deterioração. Observaram-se correlações negativas significativas entre os níveis séricos de HDL-colesterol e creatinina; HDL-colesterol e IMC; e correlações positivas significativas entre colesterol-total e uréia; LDL-colesterol e uréia; PNA/kg e HDL, triglicerídios e tirosina; triglicerídios e fibrinogênio; triglicerídios e creatinina; uréia e albumina. Conclusões: A adesão à dieta hipoprotéica foi muito pequena. A dieta hipoprotéica não interferiu no estado nutricional. A presença de inflamação influenciou, negativamente, a evolução da função renal. O perfil lipídico esteve relacionado ao estado nutricional, aos fatores de progressão da DRC e à inflamação; a lipoperoxidação esteve associada aos níveis séricos de albumina. / Background: Most metabolic disorders presented by patients with chronic renal disease (CRD) are mainly a result of accumulation of products of nitrogen metabolism, present in protein rich foods. High protein diets are associated with hyperperfusion, hypertension and hyperfiltration of the glomeruli and, as a consequence, may accelerate the progression of CRF. Nutritional therapy plays an important role in CRF treatment, consisting mainly in reduction of daily protein intake. Objective: To verify the effect of nutrition therapy intervention on nutritional status, on renal disease progression and on inflammatory and lipid parameters, oxidative status and potassium serum levels in patients with chronic renal insufficiency in the pre dialysis period. Patients and Methods: A crossover controlled prospective, randomized study in outpatients with stage IV CRD was carried out. The study consisted in the follow up of two groups of patients with CRD in the pre dialysis period. By randomization 21 patients were started on a 1g protein/kg/day diet prescription and 20 patients on low protein diet (0.6g/kg/day). After six weeks diets were reversed between the two groups and followed for another six week period. Dietetic, biochemical and anthropometric parameters were assessed at baseline and after 6 and 12 weeks. Data were analyzed according to the intention to treat approach in the crossover analysis and by adherence to the low protein diet. ANOVA for repeated measures and Spearman´s correlation tests were used for statistical analysis. The significance level adopted was P < 0.05. Results: 41 patients were evaluated. Only one patient (2.4%) was considered undernourished and 28 patients (68%) presented either over weighted or obese. Seventeen patients (41.5%) were considered inflamed according to the level of C reactive protein (CRP). Low adherence to the low protein diet was observed. Damage on nutritional status was not observed on low protein diet. In non-inflamed patients an improvement on renal function parameters was observed, whereas in the inflamed ones these parameters presented deterioration. Significant negative correlations between HDL-cholesterol serum levels and creatinine, HDL-cholesterol and body mass index (BMI) were observed. Significant positive correlations were observed between total cholesterol and urea, LDL-cholesterol and urea, PNA/kg and HDL, triglycerides and tyrosine, triglycerides and fibrinogen, triglycerides and creatinine, urea and albumin. Conclusions: Patients adhered poorly to low protein diets. Low protein diet did not influence the nutritional status. Presence of inflammation influenced negatively the evolution of renal function. The lipid profile was related to the nutritional status, to the progression factors of CRF and to inflammation. Lipoperoxidation was associated to serum levels of albumin.

Introdução: A maioria dos distúrbios metabólicos presentes na doença renal crônica (DRC) resulta, principalmente, do acúmulo de produtos do metabolismo do nitrogênio presentes nos alimentos ricos em proteínas. Dietas hiperprotéicas estão associadas à hiperperfusão, hipertensão e hiperfiltração glomerular e, conseqüentemente, à progressão da DRC. A dietoterapia tem um papel importante no tratamento da DRC, consistindo, principalmente, na redução da oferta diária de proteínas. Objetivo: Verificar o efeito da intervenção dietoterápica no estado nutricional, na progressão da doença renal e nos parâmetros inflamatórios, lipídicos, estado oxidativo e níveis séricos de potássio, de pacientes com insuficiência renal crônica em fase pré-dialítica. Pacientes e Métodos: Foi realizado um estudo prospectivo randomizado controlado cruzado em pacientes com DRC Estágio IV, em atendimento ambulatorial. O estudo constou de dois grupos de pacientes com DRC em fase pré-dialítica, que seguiram dois esquemas dietoterápicos diferentes, durante seis semanas: 21 pacientes iniciaram com prescrição de dieta normoprotéica (1 g/kg/dia) e 20 com prescrição de dieta hipoprotéica (0,6 g/kg/dia). Após esse período, os grupos inverteram as dietas. Foram avaliados parâmetros dietéticos, bioquímicos e antropométricos no momento basal e após seis e doze semanas. Os dados foram analisados segundo a intenção de tratamento na análise de crossover e por adesão à dieta hipoprotéica. Utilizaramse testes ANOVA para medidas repetidas e correlação de Spearman. O nível de significância adotado foi o de P < 0,05. Resultados: Foram avaliados 41 pacientes. Apenas um paciente (2,4%) foi considerado desnutrido e 28 (68%) apresentaram sobrepeso ou obesidade. Dezessete pacientes (41,5%) foram considerados inflamados, de acordo com o nível de PCR. Houve baixa adesão à dieta hipoprotéica.Não se observou prejuízo no estado nutricional dos pacientes durante o seguimento de prescrição de dieta hipoprotéica. Nos pacientes não inflamados observou-se melhora nos parâmetros de função renal, ao passo que, nos inflamados, estes parâmetros apresentaram deterioração. Observaram-se correlações negativas significativas entre os níveis séricos de HDL-colesterol e creatinina; HDL-colesterol e IMC; e correlações positivas significativas entre colesterol-total e uréia; LDL-colesterol e uréia; PNA/kg e HDL, triglicerídios e tirosina; triglicerídios e fibrinogênio; triglicerídios e creatinina; uréia e albumina. Conclusões: A adesão à dieta hipoprotéica foi muito pequena. A dieta hipoprotéica não interferiu no estado nutricional. A presença de inflamação influenciou, negativamente, a evolução da função renal. O perfil lipídico esteve relacionado ao estado nutricional, aos fatores de progressão da DRC e à inflamação; a lipoperoxidação esteve associada aos níveis séricos de albumina. / Background: Most metabolic disorders presented by patients with chronic renal disease (CRD) are mainly a result of accumulation of products of nitrogen metabolism, present in protein rich foods. High protein diets are associated with hyperperfusion, hypertension and hyperfiltration of the glomeruli and, as a consequence, may accelerate the progression of CRF. Nutritional therapy plays an important role in CRF treatment, consisting mainly in reduction of daily protein intake. Objective: To verify the effect of nutrition therapy intervention on nutritional status, on renal disease progression and on inflammatory and lipid parameters, oxidative status and potassium serum levels in patients with chronic renal insufficiency in the pre dialysis period. Patients and Methods: A crossover controlled prospective, randomized study in outpatients with stage IV CRD was carried out. The study consisted in the follow up of two groups of patients with CRD in the pre dialysis period. By randomization 21 patients were started on a 1g protein/kg/day diet prescription and 20 patients on low protein diet (0.6g/kg/day). After six weeks diets were reversed between the two groups and followed for another six week period. Dietetic, biochemical and anthropometric parameters were assessed at baseline and after 6 and 12 weeks. Data were analyzed according to the intention to treat approach in the crossover analysis and by adherence to the low protein diet. ANOVA for repeated measures and Spearman´s correlation tests were used for statistical analysis. The significance level adopted was P < 0.05. Results: 41 patients were evaluated. Only one patient (2.4%) was considered undernourished and 28 patients (68%) presented either over weighted or obese. Seventeen patients (41.5%) were considered inflamed according to the level of C reactive protein (CRP). Low adherence to the low protein diet was observed. Damage on nutritional status was not observed on low protein diet. In non-inflamed patients an improvement on renal function parameters was observed, whereas in the inflamed ones these parameters presented deterioration. Significant negative correlations between HDL-cholesterol serum levels and creatinine, HDL-cholesterol and body mass index (BMI) were observed. Significant positive correlations were observed between total cholesterol and urea, LDL-cholesterol and urea, PNA/kg and HDL, triglycerides and tyrosine, triglycerides and fibrinogen, triglycerides and creatinine, urea and albumin. Conclusions: Patients adhered poorly to low protein diets. Low protein diet did not influence the nutritional status. Presence of inflammation influenced negatively the evolution of renal function. The lipid profile was related to the nutritional status, to the progression factors of CRF and to inflammation. Lipoperoxidation was associated to serum levels of albumin.