Effects of turmeric extract supplementation on the lipid and lipoprotein subfraction profile in hemodialysis patients: A randomised, double-blind, crossover and controlled trial

Dyslipidemia is common in patients with chronic kidney disease. Curcumin, a bioactive polyphenol from Curcuma longa, can improve lipid profile. This study aims to analyze the effects of Curcuma Longa extract supplementation on lipid profile and lipoprotein subfractions in hemodialysis (HD) patients. This is a longitudinal, double-blind, washout-period randomized clinical trial. The patients were randomized into two groups: the curcumin group (n = 10) (orange and carrot juice with 2.5 g of Curcuma Longa extract) and the control group (n = 11) (juice without curcumin) 3x/w during HD sessions for 3 months. After the washout period, patients continued the supplementation as a crossover for the same period. The lipid profile was measured using enzymatic assays. The high-density lipoprotein and low-density lipoprotein subfractions analyses were performed using LipoprintTM. In the curcumin group, the triglyceride values tended to decrease with a different triglyceride variation between the pre and post-intervention for the control and curcumin groups of 38.5 (19.8) mg/dL (p = 0.06). There was no statistical difference in the others parameters. In conclusion, Curcuma longa extract may be a good nutritional strategy to reduce triglyceride plasma levels in hemodialysis patients, but it seems ineffective for the other parameter.

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.

Does resistance exercise performed during dialysis modulate Nrf2 and NF-κB in patients with chronic kidney disease?

Studies have shown that nuclear factor erythroid 2-related factor 2 (Nrf2) can be modulated by physical exercise. However, the impact of resistance exercise has never been investigated in patients with chronic kidney disease (CKD). The aim of this study was to evaluate the effects of resistance exercise programs on the expression of transcription factors Nrf2 and nuclear factor κB (NF-κB) in CKD patients on hemodialysis (HD). Patients on an HD program were randomly assigned to an exercise group of 25 patients (54.5% women, aged 45.7±15.2years and time on dialysis=71.2±45.5months) or a control group of 19 patients who had no exercise intervention (61.5% women, aged 42.5±13.5years and time on dialysis=70.1±49.9months). A strength exercise program was performed 3 times a week during the HD sessions. Peripheral blood mononuclear cells were isolated and processed for the expression of Nrf2 and NF-κB by quantitative real-time polymerase chain reaction 3months before and after the exercise program. Using an enzyme-linked immunosorbent assay, the activity of glutathione peroxidase (GPx) as well as the products of high-sensitivity C-reactive protein and nitric oxide (NO) were assessed. Nrf2 expression (ranging from 0.86±0.4 to 1.76±0.8) and GPx activity were significantly increased after exercise intervention. In the exercise group, no difference in the levels of NO was observed; however, there was a significant reduction in the control group. In conclusion, these data suggest that resistance exercises seem to be capable of inducing Nrf2 activation in CKD patients on HD.