Fermented food: Should patients with cardiometabolic diseases go back to an early neolithic diet?

Fermentation has been used since the Early Neolithic period to preserve foods. It has inherent organoleptic and nutritive properties that bestow health benefits, including reducing inflammation and oxidative stress, supporting the growth of salutogenic microbiota, enhancing intestinal mucosal protection and promoting beneficial immunometabolic health effects. The fermentation of food with specific microbiota increases the production salutogenic bioactive compounds that can activate Nrf2 mediated cytoprotective responses and mitigate the effects of the 'diseasome of aging' and its associated inflammageing, which presents as a prominent feature of obesity, type-2 diabetes, cardiovascular and chronic kidney disease. This review discusses the importance of fermented food in improving health span, with special reference to cardiometabolic diseases.

Can resveratrol supplementation reduce uremic toxins plasma levels from the gut microbiota in non-dialyzed chronic kidney disease patients?

BACKGROUND

Uremic toxins such as indoxyl sulfate (IS), p-cresyl sulfate (pCS), and indole-3-acetic acid (IAA) produced by the gut microbiota are recognized as risk factors for many comorbidities, including cardiovascular diseases. Chronic kidney disease (CKD) patients have an accumulation of these toxins and nutritional strategies have been proposed to mitigate gut dysbiosis and, consequently, reduce these toxins. This study aimed to evaluate the effects of resveratrol supplementation on the plasma levels of IS, pCS, and IAA in non-dialyzed CKD patients.

METHODS

In this placebo-controlled crossover study, twenty non-dialyzed patients were randomly divided into two groups: they received either one capsule/day containing 500 mg of trans-resveratrol (63 ± 7.5 years, glomerular filtration ratio (GFR): 34 ± 14 mL/min, body mass index (BMI): 26.8 ± 5.6 kg/m²) or a placebo containing 500 mg wheat flour (62 ± 8.4 years, GFR: 34 ± 13 mL/min, BMI: 28.6 ± 4.4 kg/m²) during four weeks. After eight weeks of washout (no supplementation), another four weeks of supplementation with crossover was initiated. IS, IAA, and pCS plasma levels were quantified by the Reverse Phase High-Efficiency Liquid Chromatography method with fluorescent detection. The mRNA expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa B (NF-κB) in peripheral blood mononuclear cells was evaluated by polymerase chain reaction. C-reactive protein (CRP) plasma levels were also evaluated.

RESULTS

As expected, the uremic toxins levels were negatively correlated with GFR, but no effect of trans-resveratrol supplementation was found on levels of IS, IAA, and pCS. There was a positive correlation between IS and Nrf2 (r = 0.24, p = 0.03) and also between IS and CRP (r = 0.21, p = 0.05).

CONCLUSION

Supplementation with trans-resveratrol did not reduce the plasma levels of IS, pCS, and IAA in non-dialyzed CKD patients. The interactions among uremic toxins and anti- and pro-inflammatory pathways deserve more studies.

Effects of Resveratrol Supplementation in Nrf2 and NF-κB Expressions in Nondialyzed Chronic Kidney Disease Patients: A Randomized, Double-Blind, Placebo-Controlled, Crossover Clinical Trial

INTRODUCTION

Resveratrol is a phenolic compound that has demonstrated anti-inflammatory and antioxidant effects, resulting from enhanced antioxidant enzymes production and modulating nuclear factors involved in the inflammation-oxidative stress cycle, as nuclear erythroid 2-related factor 2 (Nrf2) and nuclear factor-κB (NF-κB).

OBJECTIVE

The study aim was to evaluate the effects of resveratrol supplementation on Nrf2 and NF-κB expression in nondialyzed chronic kidney disease (CKD) patients.

MATERIALS AND METHODS

A randomized, double-blind, crossover trial was performed in 20 nondialyzed CKD patients (62.0 ± 8.0 years old, 45% men, body mass index of 27.7 ± 1.2 kg/m², estimated glomerular filtration rate of 34.0 ± 13.0 mL/minute). Eleven patients were randomly allocated to "placebo first" (4 weeks placebo; 8 weeks washout, 4 weeks 500 mg of resveratrol/day) and 9 to "resveratrol first" (4 weeks 500 mg of resveratrol/day, 8 weeks washout, 4 weeks placebo). The peripheral blood mononuclear cells were isolated and processed for expression Nrf2 and NF-κB by quantitative real-time polymerase chain reaction. Proinflammatory cytokines and antioxidant enzymes were also measured.

RESULTS

The effect size of Nrf2 supplementation (-0.13, P = .29) and NF-κB (0.09, P = .31) was not significant. There was no difference in proinflammatory biomarkers or antioxidant biomarkers after resveratrol supplementation.

CONCLUSION

In this pilot study, 500 mg of resveratrol supplementation for 4 weeks had no antioxidant and anti-inflammatory effect in nondialyzed CKD patients. Additional studies with differing doses and/or time of treatment should be conducted to better elucidate the effects of the resveratrol supplementation in CKD patients.

A practical approach to a low protein diet in Brazil

BACKGROUND

Chronic kidney disease (CKD) is an emerging health public problem in Brazil. Nutritional counseling with focus on protein restriction is a promising strategy to treatment of nondialysis CKD patients due its effects on slowing renal loss. However, Brazilian people have high protein intake, which is a challenge when low protein diet (LPD) should be prescribed. This review describes a practical approach to the dietetic management of nondialysis CKD patients in Brazil.

DISCUSSION

Although Brazilian cuisine varies greatly by region, Brazil has current trends of incorporating Western dietary habits, including high intake of red meat. Traditional plant-based foods, such as rice and beans, are also important contributors to the high protein content to the Brazilian diet. Thus, a successful implementation of LPD requires adaptation of these dietary habits, with reduction of portion sizes and adequate food substitution options. Intensive nutritional counseling with specialized renal dietitians is also important to improve compliance to the LPD. Moreover, the precarious health system organization and economic problems are barriers to nutritional care, which could be solved with intensive and specialized perspectives of treatment. The adherence to protein restriction is important for better metabolic and clinical control of nondialysis CKD patients. Early dietetic attention, nutrition education strategies and intensive specialized nutritional counseling are essential to achieve diet habits that promote adherence to the LPD without excluding cultural characteristics of the Brazilian diet.

NRF2 and NF-κB mRNA expression in chronic kidney disease: a focus on nondialysis patients

PURPOSE

To evaluate nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-kappaB (NF-κB) mRNA expression in nondialysis chronic kidney disease (CKD) patients, comparing with data from hemodialysis (HD) patients and healthy individuals.

METHODS

Twenty nondialysis CKD patients (62.0 ± 8.1 years old, 11 men, estimated glomerular filtration rate of 36.8 ± 13.6 mL/min/1.73 m(2)), twenty HD patients (55.0 ± 15.2 years old, 13 men, and dialysis vintage of 76.5 ± 46.3 months) and eleven healthy individuals (50.9 ± 8.0 years old, 6 men) were enrolled in the study. The peripheral blood mononuclear cells were isolated and processed for the evaluation of expression of NF-κB and Nrf2 by quantitative real-time polymerase chain reaction.

RESULTS

Nrf2 mRNA expression was significantly higher in nondialysis (1.12 ± 0.57) when compared to HD patients (0.58 ± 0.35, p = 0,006) but similar to healthy individuals (1.13 ± 0.64). Inversely, NF-κB mRNA expression was lower in nondialysis (1.21 ± 0.71) when compared to HD patients (2.08 ± 0.7, p < 0.0001) and similar to healthy individuals (1.04 ± 0.22). Nrf2 mRNA was positively correlated with NF-κB mRNA expression in nondialysis CKD patients (r = 0.52, p = 0.02) and healthy individuals (r = 0.77, p < 0.006). By contrast, Nrf2 mRNA was inversely correlated with NF-κB mRNA expression (r = -0.65, p = 0.003) in HD patients.

CONCLUSION

Nondialysis CKD patients may conserve regular homeostatic balance between Nrf2 and NF-κB expressions, being comparable to healthy individuals. However, HD patients seem to have Nrf2 downregulation and NF-κB upregulation. Thus, the association among Nrf2 and NF-κB expressions and nutritional status, kidney disease progression or immune deregulation deserve further investigation.

Resistance exercise training does not affect plasma irisin levels of hemodialysis patients

Irisin, a hormone secreted by myocytes induced in exercise, acts as a muscle-derived energy-expenditure signal that binds to undetermined receptors on the white adipose tissue surface, stimulating its browning and uncoupling protein 1 (UCP1) expression. The purpose of this study was to assess the effect of an intradialytic resistance exercise training program (RETP) on plasma irisin levels of hemodialysis (HD) patients and compare the baseline plasma irisin levels of HD patients to healthy subjects. This longitudinal study enrolled 26 patients undergoing HD (50% men, 44.8±14.1 years, body mass index (BMI) 23.5±3.9 kg/m²). The healthy subjects group consisted of 11 women and 7 men with mean age of 50.9±6.6 years and BMI, 24.2±2.7 kg/m². Anthropometric and biochemistry parameters (Irisin by Enzyme-Linked Immunosorbent Assay) were measured at the baseline and after 6 months of RETP (in both lower limbs). There was no difference regarding gender, age, and BMI between HD patients and healthy subjects. Plasma irisin levels in HD patients were lower than in healthy subjects (71.0±41.6 vs. 101.3±12.5 ng/ml, p<0.05). Although the muscle mass increased in consequence of exercise [evaluated by arm muscle area from 27.9 (24.1) to 33.1 (19.0) cm²], plasma irisin did not differ significantly after exercises (71.0±41.6 vs. 73.3±36.0 ng/ml). HD patients seem to have lower plasma irisin when compared to healthy subjects. Moreover, a resistance exercise training program was unable to augment plasma irisin despite increasing muscle mass.

Zinc-α2-glycoprotein: is there association between this new adipokine and body composition in hemodialysis patients?

Peptides involved in the regulation of body composition are of interest in hemodialysis (HD) patients because protein wasting associated with high fat mass (FM) is present in these patients. Zinc-α2-glycoprotein (ZAG), a new adipokine, is involved in the regulation of lipid metabolism, adiposity, and energy balance. The purpose of this study was to evaluate ZAG levels and its relationship with body composition and dietary intake in HD patients. Forty-nine HD patients (28 men, 53.1 ± 12.5 years, and BMI 24.0 ± 4.3 kg/m2) were studied and compared with 20 healthy subjects (9 men, 49.5 ± 15.2 years, and BMI 25.6 ± 4.1 kg/m(2)). Plasma ZAG levels were measured using the ELISA methods and body composition was evaluated through anthropometric data. Dietary intake was assessed 3 days by 24-hour food recall. Although most of the HD patients (59.2%) were eutrophic according to BMI, 92.3% presented high percentage of body fat (BF), and 43.5%, reduced fat-free mass according to midarm muscle circumference values. ZAG levels were ∼2.5-fold higher in HD patients (135.9 ± 40.9 mg/L) compared with healthy individuals (54.6 ± 23.0 mg/L) (p < 0.0001). Circulating ZAG was not associated with dietary intake; however, this peptide was negatively correlated with %BF and, for each 1% reduction in BF, ZAG levels increased by 2.4 mg/L (p = 0.02). In summary, circulating ZAG is increased and inversely correlated with adiposity in HD patients; however, in spite of its higher plasma levels, the majority of HD patients did not show low BF.

Underreporting of energy intake in maintenance hemodialysis patients: a cross-sectional study

OBJECTIVE

To analyze the reported energy intake (EI(rep)) in hemodialysis (HD) patients by total energy expenditure (TEE) measured by a dedicated device.

DESIGN

Cross-sectional study.

SETTING

RenalCor and RenalVida Clinics (Rio de Janeiro, Brazil).

PATIENTS AND OTHERS PARTICIPANTS

Forty-eight HD patients (51.4 ± 12.2 years, 62% men, body mass index [BMI], 23.8 ± 4.5 kg/m(2)) were studied.

MAIN OUTCOME MEASURE

EI(rep) was evaluated using a 3-day food record. TEE was measured over a 2-day period by SWA (SenseWear Pro2 Armband, BodyMedia Inc., Pittsburgh, PA). Subjects were identified as underreporters (URs), acceptable reporters (ARs), or overreporters (ORs) from their EI(rep)/TEE ratio. ARs were defined as having the EI(rep)/TEE ratio in the range of 0.76 to 1.24, URs as EI(rep)/TEE <0.76, ORs as EI(rep)/TEE >1.24 according to Goldberg index.

RESULTS

The mean TEE and EI(rep) were 34.7 ± 9.4 kcal/kg/day and 22.8 ± 10.6 kcal/kg/day, respectively, and 37.5% of patients presented overweight or obesity. Thirty-one patients (65%) were identified as URs, and the mean of Goldberg index was 0.54 ± 0.12 (0.23 to 0.75), versus 0.95 ± 0.12 (0.79 to 1.2) for ARs. There were no ORs among the patients studied. There were negative correlations between Goldberg index and BMI (r = -0.35, P < .01) and % body fat (r = -0.4, P < .01) and between EI(rep) and BMI (r = -0.58, P < .001).

CONCLUSION

These results confirm a high prevalence of underreporting of EI in HD patients, particularly in patients with high BMI.

Is zinc-α2-glycoprotein a cardiovascular protective factor for patients undergoing hemodialysis?

BACKGROUND

Zinc-α2-glycoprotein (ZAG) is a lipid mobilizing factor. Its anti-inflammatory action and expression pattern suggest that ZAG could act by protecting against the obesity-associated disorders. In hemodialysis (HD) patients, ZAG levels were described to be elevated but its effects on markers of inflammation and LDL oxidation are still unclear. We investigated the relationship between ZAG and markers of systemic inflammation and LDL atherogenic modification profile in HD patients.

METHODS

Forty-three patients regularly on HD were studied and compared to 20 healthy subjects. Plasma ZAG, adiponectin, electronegative LDL [LDL(-)], an atherosclerotic negatively charged LDL subfraction, and anti-LDL(-) autoantibodies levels were measured by ELISA. Markers of inflammation and atherogenic cell recruitment (TNF-α, interleukin-6, VCAM-1, ICAM-1, MCP-1 and PAI-1) were also determined.

RESULTS

Inflammatory markers and atherogenic cell recruitment were higher in HD patients when compared to healthy subjects. ZAG levels were also higher in HD patients (151.5 ± 50.1 mg/l vs 54.6 ± 23.0 mg/l; p<0.0001) and its levels were negatively correlated with TNF-α (r=-0.39; p=0.001) and VCAM-1 (r=-0.52; p<0.0001) and, positively correlated with anti-LDL(-) autoantibodies (r=0.38; p=0.016). On multivariate analyses, plasma ZAG levels were independently associated with VCAM-1 (p=0.01).

CONCLUSION

ZAG is inversely associated with markers of pro-atherogenic factors linked to systemic inflammation and oxidative stress. Thus, this adipokine may constitute a novel marker of a favorable metabolic profile regarding cardiovascular risk factors in HD population.

The newly identified anorexigenic adipokine nesfatin-1 in hemodialysis patients: Are there associations with food intake, body composition and inflammation?

Nesfatin-1 is a recently identified anorexigenic peptide that has been implicated in appetite regulation, weight loss and/or malnutrition. Anorexia and malnutrition are common features of chronic kidney disease (CKD) that predispose patients to worse outcomes. However, the reasons for the occurrence of anorexia in CKD patients are not fully elucidated. The aim of this study was to investigate the association between nesfatin-1 and protein intake and body composition in patients undergoing hemodialysis (HD). Twenty five HD patients from a private Clinic in Rio de Janeiro, Brazil were studied and compared with 15 healthy subjects that were matched for body mass index (BMI), % body fat mass (by anthropometrics) and age. Appetite was measured using a specific questionnaire, and food intake was evaluated based on 3-day food records. Nesfatin-1 levels were measured by ELISA and leptin, TNF-α and IL-6 levels were determined by a multiplex assay kit. Serum nesfatin-1 levels did not differ between HD patients (0.16±0.07ng/mL) and healthy subjects (0.17±0.10ng/mL). Nesfatin-1 levels showed significant negative correlations with protein intake (r=-0.42; p=0.03), but did not associate with inflammatory markers or appetite scores. Combining patients and controls, we observed positive correlations with BMI (r=0.33; p=0.03), % body fat (r=0.35; p=0.03), leptin (r=0.45; p=0.006) and the triceps skinfold thickness (r=0.36; p=0.02). In multivariate analysis % body fat was the main determinant of nesfatin-1 variance. In conclusion, nesfatin-1 levels did not differ between HD patients and healthy subjects and negatively correlated with protein intake. This pathway is likely not dysregulated in uremia.

Relationship between total ghrelin and inflammation in hemodialysis patients

In hemodialysis (HD) patients studies have shown that plasma ghrelin is increased and it has been speculated that ghrelin levels might be related to systemic inflammation. The present study attempted to correlate the serum levels of total ghrelin with serum TNF-α and IL-6, and with nutritional status and body composition in HD patients. Forty-seven HD patients from a single dialysis unit (18 women, mean age 55.3±12.2 yr; BMI 24.4±4.2kg/m(2); % body fat 29.4±7.4%) were studied and compared to 21 healthy subjects (12 women, 50.7±15.7 yr and BMI 25.6±4.0kg/m(2); % body fat 30.0±5.7%). Biochemical data, serum total ghrelin, TNF-α and IL-6 levels were measured. The body composition was evaluated by dual energy X-ray absortiometry (DEXA) and energy and protein intake were evaluated. Patients showed elevated plasma ghrelin levels when compared to healthy subjects (1.14±1.0ng/mL vs 0.58±0.4; p<0.001). There was a positive correlation between ghrelin levels and TNF-α (r=0.25; p<0.04), IL-6 (r=0.42; p<0.02), and a negative correlation between TNF-α and protein intake (r=-0.28; p<0.03), and energy intake (r=-0.34; p<0.01). No correlation was observed with any aspect of body composition. Plasma ghrelin levels are elevated in HD patients and associated with the state of systemic inflammation. We suggest that the inflammatory state may affect ghrelin bioactivity and metabolism in hemodialysis patients.

Use of handgrip strength in the assessment of the muscle function of chronic kidney disease patients on dialysis: a systematic review

BACKGROUND

Even though handgrip strength (HGS) is considered a simple and reliable method to evaluate muscle function and, indirectly, the nutritional status in clinical settings, there is still no consensus concerning its use in patients with chronic kidney disease (CKD) undergoing dialysis. This study presents a systematic review of the literature on the use of HGS as a parameter for nutritional assessment and a prognostic marker in patients on dialysis.

METHODS

The MEDLINE database (1966 to October 2009) was consulted for this systematic review by using the search terms hand strength or muscle strength dynamometer and dialysis. Eighteen articles were identified and included in the analysis.

RESULTS

Similar to the general population, HGS values were associated with age and gender. The analysed studies showed correlation between muscle function estimated by HGS and variables used in the assessment of muscle mass and nutritional status, as well as the prediction of clinical complications.

CONCLUSIONS

The analysis indicates that HGS is a useful tool for continuous and systematic assessment of muscle mass related to nutritional status in patients on dialysis. However, it is still necessary to standardize the techniques used for HGS, especially with respect to the position of measurement, the evaluation period, the choice of arm side and the diagnostic criterion.

Influence of renal function and diet on acid-base status in chronic kidney disease patients

OBJECTIVE

We investigated the influence of potential renal acid load (PRAL) and renal function on the degree of metabolic acidosis in patients with chronic kidney disease (CKD).

DESIGN

This was a cross-sectional study.

SETTING

This study was conducted at the Nephrology Outpatient Division of the Hospital Universitário Clementino Fraga Filho (Rio de Janeiro, Brazil).

PATIENTS

Thirty CKD patients undergoing conservative treatment were divided according to plasma HCO(3)(-) values into acidotic (HCO(3)(-) <or=22 mM, n = 15) and nonacidotic (HCO(3)(-) >22 mM, n = 15).

MAIN OUTCOME MEASURE

Biochemical, nutritional, and anthropometric parameters and PRAL were measured.

RESULTS

The mean of plasma HCO(3)(-) values was 17.7 +/- 2.8 mM in the acidotic group, and 25.1 +/- 2.2 mM in the nonacidotic group. There was no significant difference in mean PRAL values between the acidotic (9.8 +/- 6.4 mEq/day) and nonacidotic (12.7 +/- 10.0 mEq/day) groups, but there was a significant correlation between plasma HCO(3)(-) and creatinine clearance (r = 0.78, P < .0001). Based on the receiver operating characteristic curve, the level of creatinine clearance to begin detection of acidosis was 31.8 mL/min, with a sensitivity and specificity of 86.7%.

CONCLUSION

The acid-base status of this group of CKD patients undergoing conservative treatment was mainly determined by degree of renal insufficiency rather than diet.