Effects of Low Protein Diet on Nuclear Factor Erythroid 2-Related Factor 2 Gene Expression in Nondialysis Chronic Kidney Disease Patients.

OBJECTIVE(S): Low protein diets (LPD; 0.6 g/kg/day), prescribed for nondialysis chronic kidney disease (CKD) patients, have demonstrated numerous benefits. LPDs may modulate inflammation and oxidative stress through the nuclear factor erythroid 2-related factor 2 (Nrf2), which encodes antioxidant and phase II detoxifying enzymes. LPDs also inhibit or antagonize nuclear factor kB (NF-kB) activity, which orchestrates inflammatory and oxidative stress responses. The objective of this study was to evaluate the effects of LPD on Nfr2 and NF-κB messenger RNA (mRNA) expression in nondialysis CKD patients. METHODS: In this longitudinal study, a LPD was prescribed for 30 nondialysis CKD patients for 6 months. Peripheral blood mononuclear cells were isolated, and quantitative real-time polymerase chain reaction analysis was performed to evaluate Nrf2, NF-κB, and NADPH quinine oxidoreductase-1 mRNA expression. Thiobarbituric acid-reactive substance (TBARS) levels, a marker of lipid peroxidation, were also evaluated. RESULTS: (Age 55.5 ± 14.0 years; body mass index 29.1 ± 5.9 kg/m2; glomerular filtration rate 35.6 ± 12.2 mL/minute). After 6 months of nutritional intervention, Nrf2 mRNA expression increased from 0.85 (0.47-1.56) to 1.28 (0.63-2.63) nmol/mL (P = .03), and TBARS levels were significantly decreased from 1.78 (1.31-2.38) to 1.30 (1.07-2.22) nmol/mL (P = .04). NF-κB mRNA expression showed no significant difference after 6 months, but the Nrf2/NF-κB ratio was increased. CONCLUSION(S): In this study, a LPD appeared to modulate Nrf2 expression and decrease the levels of TBARS in nondialysis CKD patients. However, more studies are needed to confirm the effectiveness of LPD on the modulation of transcription factors involved with oxidative stress and inflammation in nondialysis CKD patients.

Effects of Low-Protein Diet on lipid and anthropometric profiles of patients with chronic kidney disease on conservative management / Efeitos da dieta hipoproteica sobre os perfis lipídico e antropométrico de pacientes com doença renal crônica em tratamento conservador

ABSTRACT Introduction: Chronic Kidney disease (CKD) patients have a high prevalence of cardiovascular mortality, and among the risk factors are dyslipidemia and obesity, common findings in the early stages of CKD. The aim of this study was to evaluate the effects of low protein diet (LPD) on the lipid and anthropometric profile in non-dialysis CKD patients. Methods: Forty CKD patients were studied (20 men, 62.7 ± 15.2 years, glomerular filtration rate (GFR) 26.16 ± 9.4 mL/min/1.73m2). LPD (0.6g/kg/d) was prescribed for six months and, biochemical and anthropometric parameters like body mass index (BMI), waist circumference and body fat mass (assessed by dual X-ray absorptiometry - DXA) were evaluated before and after six months with LPD. Results: After six months of nutritional intervention, patients presented reduction on BMI (from 28.1 ± 5.6 to 27.0 ± 5.3 Kg/m2, p = 0.001), total cholesterol (from 199.7 ± 57.1 to 176.0 ± 43.6mg/dL, p = 0.0001), LDL (from 116.2 ± 48.1 to 97.4 ± 39.1 mg/dL, p = 0,001) and uric acid (from 6.8 ± 1.4 to 6.2 ± 1.3 mg/dL, p = 0.004). In addition, GFR values were increased from 26.2 ± 9.5 to 28.9 ± 12.7mL/min (p = 0.02). The energy, proteins, cholesterol and fiber intake were reduced significantly. Conclusion: LPD prescribe to non-dialysis CKD patients for six months was able to improve some cardiovascular risk factors as overweight and plasma lipid profile, suggesting that LPD can be also an important tool for protection against cardiovascular diseases in these patients.

RESUMO Introdução: Pacientes com Doença Renal Crônica (DRC) possuem alta prevalência de mortalidade cardiovascular e, dentre os fatores de risco, encontram-se alterações no perfil lipídico e excesso de peso, que são achados comuns na DRC. O objetivo deste estudo foi avaliar os efeitos da dieta hipoproteica sobre o perfil antropométrico e lipídico de pacientes com DRC em tratamento conservador. Métodos: Foram estudados 40 pacientes com DRC (20 homens, 62,7 ± 15,2 anos, e Taxa de Filtração Glomerular (TFG) de 26,2 ± 9,4 mL/min/1,73m2). Os pacientes receberam prescrição de dieta hipoproteica (0,6g/kg/d) e parâmetros bioquímicos e antropométricos como índice de massa corporal (IMC), circunferência da cintura (CC) e percentual de gordura corporal (GC) avaliado por absorciometria com raio-x de dupla energia (DXA), foram analisados antes e após 6 meses de intervenção. Resultados: Os pacientes apresentaram após 6 meses, redução do IMC (de 28,1 ± 5,6 para 27,0 ± 5,3Kg/m2, p = 0,001), colesterol total (de 199,7 ± 57,1 para 176,0 ± 43,6mg/dL, p = 0,0001), LDL (de 116,2 ± 48,1 para 97,4 ± 39,1 mg/dL, p = 0,001) e ácido úrico (de 6,8 ± 1,4 para 6,2 ± 1,3 mg/dL, p = 0,004) e, aumento da TFG de 26,2 ± 9,5 para 28,9 ± 12,7mL/min (p = 0,02). Houve redução significativa na ingestão de energia e proteínas, bem como de colesterol e fibras. Conclusão: A intervenção com dieta hipoproteica para pacientes com DRC em tratamento conservador por seis meses foi capaz de melhorar alguns fatores de risco cardiovascular, como o excesso de peso e o perfil lipídico plasmático, sugerindo que a dieta hipoproteica, além de outros benefícios pode também ser importante ferramenta para a proteção de doenças cardiovasculares nesses pacientes.