Vitamin D deficiency is not associated with increased oxidative stress in chronic kidney disease pre-dialysis patients.

INTRODUCTION: The progressive decline in 25-hydroxyvitamin D [25(OH)D] in chronic kidney disease (CKD) limits the kidney ability of synthesizing the vitamin. Vitamin D deficiency as defined by KDIGO (25(OH)D <20 ng/mL) is prevalent in CKD patients and associated to oxidative stress (OS). We studied a possible association between vitamin D deficiency and OS in pre-dialysis patients. METHODS: A cross-sectional study with 206 CKD patients was carried out. Laboratory tests for 25(OH)D, 1,25(OH)2D, inflammatory markers, and OS were added to routine tests including creatinine, albumin, calcium, phosphorus, alkaline phosphatase, iPTH, glucose, hemoglobin, uric acid, total cholesterol, LDL, HDL, and triglycerides. RESULTS: Vitamin D deficiency was present in 55 CKD patients and normal vitamin D levels were seen in 149 patients. There was a significant association between vitamin D and estimated glomerular filtration rate (eGRF). Homocysteine levels were best predicted by eGRF, sex, and age; high sensitivity C-reactive protein (hsCRP) by staging and BMI; nitric oxide metabolites (NOx) were increased in late disease; leptin was influenced by BMI and higher in women than man; and adiponectin levels were higher in women. CONCLUSIONS: OS biomarkers were not correlated with vitamin D deficiency but increased NOx were seen in stages 4-5 CKD patients. Even though a relatively large number of CKD patients was included and a broad number of OS and inflammatory biomarkers were used in this studied we failed to find an association between vitamin D levels and eGRF. More studies are needed to evaluate the influence of vitamin D status in OS in pre-dialysis CKD patients.

Addition of vitamin D reverses the decline in GFR following treatment with ACE inhibitors/angiotensin receptor blockers in patients with chronic kidney disease.

AIMS: Vitamin D has anti-inflammatory, anti-fibrotic effect, and may block the intrarenal renin-angiotensin system. Adequate vitamin D levels in conjunction with the use of Angiotensin-converting Enzyme Inhibitors/Angiotensin Receptor Blockers may help to slow down chronic kidney disease progression. MAIN METHODS: To study a possible beneficial effect of vitamin D supplementation in chronic kidney disease patients using angiotensin-converting enzyme inhibitors/angiotensin receptor blockers on chronic kidney disease progression we performed a clinical study involving vitamin D supplementation in patients with deficiency of this vitamin. This study was conducted in two chronic kidney disease clinics in the city of Londrina, Brazil, from October 2010 to December 2012. It was involved stage 3 and 4 chronic kidney disease (estimated glomerular filtration rate between 60 and 15mL/min/1.73m2) patients with and without vitamin D deficiency. The patients ingested six-month cholecalciferol 50,000IU oral supplementation to chronic kidney disease patients with vitamin D deficiency. We hypothesize changes in estimated glomerular filtration rate over study period. SIGNIFICANCE: Our data demonstrate reservation of estimated glomerular filtration with cholecalciferol supplementation to chronic kidney disease patients taking angiotensin-converting enzyme inhibitors/angiotensin receptor blockers. The combination treatment of angiotensin converting enzyme inhibitors/angiotensin receptor blockers with cholecalciferol prevents the decline in estimated glomerular filtration in patients with chronic kidney disease following treatment with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and may represent a valid approach to reduce renal disease progression in chronic kidney disease patients with vitamin D deficiency. This result needs confirmation in prospective controlled clinical trials.

Vitamin D deficiency is not associated with increased oxidative stress in chronic kidney disease pre-dialysis patients / A deficiência de vitamina D não está associada ao aumento do estresse oxidativo em pacientes renais crônicos em pré-diálise

Abstract Introduction: The progressive decline in 25-hydroxyvitamin D [25(OH)D] in chronic kidney disease (CKD) limits the kidney ability of synthesizing the vitamin. Vitamin D deficiency as defined by KDIGO (25(OH)D <20 ng/mL) is prevalent in CKD patients and associated to oxidative stress (OS). We studied a possible association between vitamin D deficiency and OS in pre-dialysis patients. Methods: A cross-sectional study with 206 CKD patients was carried out. Laboratory tests for 25(OH)D, 1,25(OH)2D, inflammatory markers, and OS were added to routine tests including creatinine, albumin, calcium, phosphorus, alkaline phosphatase, iPTH, glucose, hemoglobin, uric acid, total cholesterol, LDL, HDL, and triglycerides. Results: Vitamin D deficiency was present in 55 CKD patients and normal vitamin D levels were seen in 149 patients. There was a significant association between vitamin D and estimated glomerular filtration rate (eGRF). Homocysteine levels were best predicted by eGRF, sex, and age; high sensitivity C-reactive protein (hsCRP) by staging and BMI; nitric oxide metabolites (NOx) were increased in late disease; leptin was influenced by BMI and higher in women than man; and adiponectin levels were higher in women. Conclusions: OS biomarkers were not correlated with vitamin D deficiency but increased NOx were seen in stages 4-5 CKD patients. Even though a relatively large number of CKD patients was included and a broad number of OS and inflammatory biomarkers were used in this studied we failed to find an association between vitamin D levels and eGRF. More studies are needed to evaluate the influence of vitamin D status in OS in pre-dialysis CKD patients.

Resumo Introdução: A queda da 25-hidroxivitamina D [25 (OH) D] na doença renal crônica (DRC) limita a capacidade renal de sintetizar a vitamina. A deficiência de vitamina D, (25(OH)D<20 ng/mL), é prevalente em pacientes com DRC e associada ao estresse oxidativo (EO). Avaliamos possível associação entre a deficiência de vitamina D e EO em pacientes pré-dialíticos. Métodos: estudo transversal com 206 pacientes com DRC. Exames para 25(OH)D, 1,25(OH)2D, marcadores inflamatórios e EO foram adicionados àqueles de rotina, incluindo creatinina, albumina, cálcio, fósforo, fosfatase alcalina, iPTH, glicose, hemoglobina, ácido úrico, colesterol total , LDL, HDL e triglicerídeos. Resultados: 55 pacientes com DRC tinham deficiência de vitamina D e os 149 tinham níveis normais da vitamina. Houve uma associação significativa entre a vitamina D e a taxa estimada de filtração glomerular (TFGe). Os níveis de homocisteína foram melhor previstos pela TFGe, gênero e idade; proteína C reativa de alta sensibilidade (hsCRP) por estadiamento e IMC; os metabólitos de óxido nítrico (NOx) aumentaram na doença tardia; a leptina foi influenciada pelo IMC, e mais alta em mulheres, assim como os níveis de adiponectina. Conclusões: biomarcadores do EO não correlacionaram com a deficiência de vitamina D, mas houve aumento de NOx nos estágios 4-5 da DRC. Apesar dos grandes números de pacientes com DRC, de biomarcadores inflamatórios e EO usados neste estudo, não houve associação entre os níveis de vitamina D e a TFGe. Mais estudos são necessários para avaliar a influência do status da vitamina D no EO em pacientes com DRC em pré-diálise.

[Effect of n-3 fatty acids in glycemic and lipid profiles, oxidative stress and total antioxidant capacity in patients with the metabolic syndrome]. / Efeito dos ácidos graxos n-3 no perfil glicêmico e lipídico, no estresse oxidativo e na capacidade antioxidante total de pacientes com síndrome metabólica.

OBJECTIVE: Metabolic syndrome (MS) is a cluster of factors which favors the development of cardiovascular diseases. Previous studies have shown that polyunsaturated fatty acids (PUFAs) can improve some of these factors. This study aimed to evaluate the effect of fish oil on glucose and lipid profiles, oxidative stress and total antioxidant capacity (TRAP) in patients with MS. SUBJECTS AND METHODS: We conducted a clinical trial in 40 patients with the MS (20 controls and 20 patients receiving 3 g/day of PUFAs). SUBJECTS AND RESULTS: The group that received treatment showed a significant decrease in levels of triglycerides and increased in TRAP, but they had a significant increase in LDL, glucose and insulin resistance. CONCLUSION: We conclude that intake of fish oil resulted in decreased levels of triglycerides and increased the TRAP of patients with MS; however, increased LDL levels and insulin resistance, were observed.

Efeito dos ácidos graxos n-3 no perfil glicêmico e lipídico, no estresse oxidativo e na capacidade antioxidante total de pacientes com síndrome metabólica / Effect of n-3 fatty acids in glycemic and lipid profiles, oxidative stress and total antioxidant capacity in patients with the metabolic syndrome

OBJETIVO: A síndrome metabólica (SM) é um conjunto de fatores que favorecem o desenvolvimento de doenças cardiovasculares. Estudos prévios demonstram que os ácidos graxos poliinsaturados (PUFAs) podem melhorar alguns desses fatores. O objetivo foi avaliar o efeito do óleo de peixe rico em PUFAs nos perfis glicêmico e lipídico, no estresse oxidativo e na capacidade antioxidante total (TRAP) no plasma em pacientes com SM. SUJEITOS E MÉTODOS: Foi realizado um ensaio clínico em 40 pacientes com SM (20 controles e 20 pacientes que consumiram 3 g/dia de PUFAs). RESULTADOS: O grupo que recebeu tratamento apresentou redução significativa nos níveis de triacilgliceróis e aumento no TRAP, mas sofreu aumento nos níveis de LDL, glicose e na resistência à insulina. CONCLUSÃO: Conclui-se que a ingestão de óleo de peixe foi capaz de diminuir os níveis de triacilgliceróis e aumentar o TRAP de pacientes com SM, porém verificou-se aumento nos níveis de LDL e na resistência à insulina.

OBJECTIVE: Metabolic syndrome (MS) is a cluster of factors which favors the development of cardiovascular diseases. Previous studies have shown that polyunsaturated fatty acids (PUFAs) can improve some of these factors. This study aimed to evaluate the effect of fish oil on glucose and lipid profiles, oxidative stress and total antioxidant capacity (TRAP) in patients with MS. SUBJECTS AND METHODS: We conducted a clinical trial in 40 patients with the MS (20 controls and 20 patients receiving 3 g/day of PUFAs). SUBJECTS AND RESULTS: The group that received treatment showed a significant decrease in levels of triglycerides and increased in TRAP, but they had a significant increase in LDL, glucose and insulin resistance. CONCLUSION: We conclude that intake of fish oil resulted in decreased levels of triglycerides and increased the TRAP of patients with MS; however, increased LDL levels and insulin resistance, were observed.

Importância da ingestão de soja nos sintomas do climatério, osteoporose e doenças cardiovasculares / The importance of soy ingestion in postmenopausal symptoms, osteoporosis, and cardiovascular diseases

A soja é um alimento consumido especialmente por orientais e seu consumo data de pelo menos 5.000 anos. Os grãos de soja são ricos em proteínas e em fitoestrógenos, as isoflavonas, e seu consumo tem sido implicado na prevenção de doenças. Estudos epidemiológicos demonstraram que, em países orientais, a taxa de morbidade e mortalidade para doenças cardiovasculares, diabetes e câncer é menor do que a dos países ocidentais. Outro fato que merece ser salientado é que mulheres orientais, na menopausa, queixam-se muito menos dos sintomas do climatério do que as ocidentais. Estes resultados parecem ser devido ao maior consumo de soja por aquela população. Esta revisão examina as evidências e os possíveis mecanismos envolvidos entre o consumo de soja, a melhora dos sintomas do climatério e a prevenção de doenças cardiovasculares e metabólicas. Os sintomas do climatério, como, por exemplo, os fogachos e o aumento da incidência de osteoporose, são atenuados com o consumo da soja. As isoflavonas, além de sua ação hipoglicêmica, têm sido implicadas na prevenção de doenças cardiovasculares, por melhorarem o perfil lipídico dos pacientes. Com relação aos biomarcadores e citocinas inflamatórias, apesar de incipientes, os resultados das pesquisas são promissores. Por outro lado, o metabolismo de ferro parece ser afetado pelo seu consumo. Embora ainda existam alguns resultados contraditórios quanto ao consumo de soja, esta é indicada a todos que desejam ter uma alimentação saudável, realizar um tratamento natural para os sintomas do climatério e, ao mesmo tempo, prevenir doenças metabólicas.

Soy based products are consumed by oriental people for more than 5000 years. Soy grains are rich in proteins and phytoestrogens, the isofl avones, and soy consume have been implicated in disease prevention. Epidemiological studies have shown that cardiovascular disease, diabetes and cancer present higher morbidity and mortality in occidental than oriental countries. Another issue that deserves consideration is that oriental pos menopausal women are less symptomatic than the occidental ones, and soy ingestion seems to be an important cause. This review analyses the evidences and possible mechanisms evolved in the action of soy and its relationship with postmenopausal symptoms, cardiovascular and metabolic diseases. Isofl avones, besides a hypoglycemic action, have been implicated in the prevention of cardiovascular disease by improving lipid profi le. Infl ammatory biomarkers and cytokines research, although incipient, show promising results. On the other hand, iron metabolism seems to be negatively affected by soy ingestion. In spite of some contradictory results, long term ingestion of soy based products seems an appropriate measure to all persons who wish to consume a healthy food diet, proportioning a natural treatment of postmenopausal symptoms and the prevention of cardiovascular diseases.

Efeitos e mecanismos de ação dos ácidos graxos poliinsaturados n-3 na prevenção de doenças cardiovasculares / Mechanisms of action of polyunsaturated n-3 fatty acids for cardiovascular disease prevention

A ingestão de óleo de peixe tem demonstrado efeitos benéficos na prevenção das doenças cardiovasculares (DCV) e este efeito está relacionado à presença de ácidos graxos poliinsaturados n-3, em especial dos ácidos eicosapentaenóico (EPA, C20:5n-3) e docosahexaenóico (DHA, C22:6n-3), encontrados nos óleos de peixes de águas frias e profundas como salmão, arenque, atum e sardinhas. Estes compostos têm demonstrado importante ação antilipêmica, antiinflamatória, antitrombótica, antiarrítimica, anti-hipertensiva, entre outras. A ingestão de óleo de peixe em pacientes com doença cardíaca isquêmica e hiperlipoproteinemia diminuiu os níveis séricos de fibrinogênio, a viscosidade plasmática e a resistência vascular periférica total. Eles também atuam ajudando a manter a elasticidade da parede das artérias, impedindo a coagulação do sangue, reduzindo a pressão sangüínea e estabilizando a arritmia cardíaca. O seu principal efeito nas doenças coronárias é a redução da produção de tromboxana A2, agregante plaquetário que favorece a trombose. Outra ação destes compostos é a redução nos níveis de triacilgliceróis e da lipoproteína de densidade muito baixa (VLDL), porém com aumento da lipoproteína de baixa densidade (LDL). O aumento da LDL com redução da VLDL parece estar relacionado com a conversão da VLDL em LDL ou à redução na atividade do receptor de LDL. O EPA e o DHA modulam a resposta inflamatória, atuando na diminuição da transcrição de citocinas pró-inflamatórias e na expressão de moléculas de adesão na superfície vascular. Este estudo propõe-se a revisar os principais mecanismos envolvidos na prevenção de DCV pelos ácidos graxos n-3.

Fish oil ingestion has shown beneficial effects for cardiovascular disease (CVD) prevention, and this effect is related to the polyunsaturated fatty acids, specially eicosapentaenoic (EPA, C20:5n-3) and docosahexaenoic (DHA, C22:6n-3), found in fish from cold and deep water, such as salmon, tune and sardine. These compounds have important antilipidemic, antiinflammatory, antithrombotic, antiarrhytmic, and antihypertensive action. Fish oil ingestion in patients with ischemic heart disease and hyperlipoproteinemia decreased fibrinogen serum levels, plasmatic viscosity and total peripheral resistance. They also act by helping to maintain artery wall elasticity, preventing blood coagulation, reducing blood pressure and preventing fatal cardiac arrhythmias. Their major effect in coronary disease isthe decrease production of thromboxane A2, platelet aggregant that favors thrombosis; another effect is the reduction of tryacylglicerol levels and very low density lipoprotein (VLDL), although with low density lipoprotein (LDL) increase. This increment seems related to the conversion of VLDL in LDL or to the decreased activity of LDL receptor. EPA and DHA modulate inflammatory reaction through the reduction of pro-inflammatory cytokines transcription and adhesion molecules expression on the vascular surface. This review proposes to study the main mechanisms evolved in CVD prevention by n-3 polyunsaturated fatty acids.