Effects of omega-3 fatty acid plus alpha-tocopherol supplementation on malnutrition–inflammation score, biomarkers of inflammation and oxidative stress in chronic hemodialysis patients

Efficacy of antioxidant intervention and exercise intervention for lipid peroxidation in dialysis patients: a meta-analysis

Background

Lipid peroxidation is a major factor known to contribute to occurrence of cardiovascular events in dialysis patients. This study aims to investigate whether antioxidant interventions can improve lipid peroxidation damage in dialysis patients.

Methods

A comprehensive search in PubMed, Embase, and the Cochrane Library was conducted to identify eligible randomized controlled trials (RCTs) up to June 2024. Endpoints of interest included biomarkers related to Lipid peroxidation. The results from eligible studies were performed using RevMan 5.3 and Stata17.0 software.

Results

A total of 25 RCTs were included, involving eight interventions such as vitamin C supplementation, vitamin E supplementation, vitamin E-coated dialyzer, ω-fatty acid supplementation, curcumin supplementation, pomegranate juice supplementation, exercise intervention, and multiple antioxidant interventions. Outcome indicators included malondialdehyde (MDA) and oxidized low-density lipoprotein (Ox-LDL). The meta-analysis revealed that vitamin E supplementation caused significant reductions in MDA (p = 0.01). Treatment with vitamin E-coated dialyzer markedly decreased MDA levels (p < 0.0001). Curcumin supplementation significantly reduced Ox-LDL levels (p = 0.03). Exercise intervention decreased MDA levels (p < 0.0001). Multiple antioxidant interventions significantly decreased MDA (p = 0.01).

Conclusion

Supplementation of vitamin E, vitamin E-coated dialyzer treatment, curcumin supplementation, exercise intervention, and multiple antioxidant interventions can effectively reduce the level of lipid peroxidation biomarkers in dialysis patients.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO (CRD42023455399).

Effect of oral nutritional supplements on inflammation and oxidative stress in hemodialysis patients: a meta-analysis

OBJECTIVE

This study aims to elucidate the effects of oral nutritional supplements on inflammatory factors and antioxidant status in patients undergoing hemodialysis through a meta-analysis of previous research.

METHODS

This study conducted literature databases from inception to November 2024, including PubMed, Embase, Cochrane, Wanfang, and China National Knowledge Infrastructure (CNKI), to identify all published randomized controlled trials assessing the impact of oral nutritional supplementation on inflammation and oxidative stress in patients on maintenance hemodialysis. Heterogeneity was assessed using the Chi-square test. Subgroup analyses and sensitivity analyses were performed to explore the sources of heterogeneity. Publication bias was evaluated using funnel plots and the Egger test.

RESULTS

Supplementation with unsaturated fatty acids did not significantly affect serum CRP levels in patients undergoing hemodialysis (MD = - 0.93, 95% CI [- 2.53, 0.68], Z = 1.13, P = 0.26). The total antioxidant capacity in the antioxidant group was higher than that in the control group (MD = 0.09, 95% CI [0.05, 0.14], Z = 4.41, P < 0.0001). The MDA levels in the antioxidant group were lower than those in the control group (MD = - 2.28, 95% CI [- 2.75, - 1.80], Z = 9.42, P < 0.0001), while the difference in IL-6 levels between the antioxidant group and the control group was not statistically significant (MD = - 0.10, 95% CI [- 0.56, 0.36], Z = 0.41, P = 0.68).

CONCLUSION

Unsaturated fatty acids do not have a significant effect on serum CRP levels in patients undergoing hemodialysis. The antioxidants (vitamin E and polyphenols) can enhance the antioxidant capacity and reduce MDA levels in these patients; however, their impact on IL-6 levels is not significant. Further high-quality randomized controlled trials are needed to validate these conclusions.

Effectiveness of fish oil in controlling inflammation in adult patients undergoing hemodialysis: A systematic review and meta-analysis

Objective

Hemodialysis patients with chronic kidney disease often exhibit inflammation characterized by elevated levels of C-reactive protein, Interleukin 6 and tumor necrosis factor-alpha, and they are shown to be associated with cardiovascular impairment and enhanced renal failure. This study aims to assess the impact of fish oil intake on inflammation indicators in adult hemodialysis patients.

Methods

From the inception to December 2023, the datasets Cochrane Central, Google Scholar, Science Direct, Embase, and Pubmed were examined. Two authors independently searched, selected, and screened the literature. The pooled results are represented by weighted mean difference (WMD) with 95% confidence intervals. To investigate the causes of heterogeneity, subgroup analysis was done. Sensitivity analysis was then used to evaluate the validity of the combined findings.

Results

Thirteen randomized control trials studies were included. The pooled results showed that fish oil supplementation caused a significant reduction of the C-reactive protein level (WMD, -2.92 mg/L; 95% Confidence interval, -5.23, to -0.61; p = 0.01; I 2 = 99%), especially in patients with baseline C-reactive protein ⩾5 mg/L (WMD, -4.39 mg/L; 95% Confidence interval, -5.93 to 2.85; p < 0.00001; I 2 = 33%). Subgroup analyses showed that C-reactive protein baseline level (C-reactive protein <5 mg/L) was the main source of heterogeneity. Fish oil intake may not reduce the level of Interleukin 6 (WMD, -2.26; 95% Confidence interval: -19.61 to 15.09; p = 0.80; I 2 = 93%), nor will it reduce the level of tumor necrosis factor-alpha (random model: WMD, -2.51; 95% Confidence interval: 6.08 to 1.06; p = 0.17; I 2 = 98%).

Conclusion

Hemodialysis patients, especially those with C-reactive protein > 5 mg/L, responded to fish oil supplementation to reduce their C-reactive protein level; however, Interleukin 6 and tumor necrosis factor-alpha levels did not appear to be affected.

From genes to systems: The role of food supplementation in the regulation of sepsis-induced inflammation

Systemic inflammation includes a widespread immune response to a harmful stimulus that results in extensive systemic damage. One common example of systemic inflammation is sepsis, which is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Under the pro-inflammatory environment of sepsis, oxidative stress contributes to tissue damage due to dysfunctional microcirculation that progressively causes the failure of multiple organs that ultimately triggers death. To address the underlying inflammatory condition in critically ill patients, progress has been made to assess the beneficial effects of dietary supplements, which include polyphenols, amino acids, fatty acids, vitamins, and minerals that are recognized for their immuno-modulating, anticoagulating, and analgesic properties. Therefore, we aimed to review and discuss the contribution of food-derived supplementation in the regulation of inflammation from gene expression to physiological responses and summarize the precedented potential of current therapeutic approaches during systemic inflammation.

Antioxidants for adults with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a significant risk factor for cardiovascular disease (CVD) and death. Increased oxidative stress in people with CKD has been implicated as a potential causative factor. Antioxidant therapy decreases oxidative stress and may consequently reduce cardiovascular morbidity and death in people with CKD. This is an update of a Cochrane review first published in 2012.

OBJECTIVES

To examine the benefits and harms of antioxidant therapy on death and cardiovascular and kidney endpoints in adults with CKD stages 3 to 5, patients undergoing dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies until 15 November 2022 using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included all randomised controlled trials investigating the use of antioxidants, compared with placebo, usual or standard care, no treatment, or other antioxidants, for adults with CKD on cardiovascular and kidney endpoints.

DATA COLLECTION AND ANALYSIS

Titles and abstracts were screened independently by two authors who also performed data extraction using standardised forms. Results were pooled using random effects models and expressed as risk ratios (RR) or mean difference (MD) with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 95 studies (10,468 randomised patients) that evaluated antioxidant therapy in adults with non-dialysis-dependent CKD (31 studies, 5342 patients), dialysis-dependent CKD (41 studies, 3444 patients) and kidney transplant recipients (21 studies, 1529 patients). Two studies enrolled dialysis and non-dialysis patients (153 patients). Twenty-one studies assessed the effects of vitamin antioxidants, and 74 assessed the effects of non-vitamin antioxidants. Overall, the quality of included studies was moderate to low or very low due to unclear or high risk of bias for randomisation, allocation concealment, blinding, and loss to follow-up. Compared with placebo, usual care, or no treatment, antioxidant therapy may have little or no effect on cardiovascular death (8 studies, 3813 patients: RR 0.94, 95% CI 0.64 to 1.40; I² = 33%; low certainty of evidence) and probably has little to no effect on death (any cause) (45 studies, 7530 patients: RR 0.95, 95% CI 0.82 to 1.11; I² = 0%; moderate certainty of evidence), CVD (16 studies, 4768 patients: RR 0.79, 95% CI 0.63 to 0.99; I² = 23%; moderate certainty of evidence), or loss of kidney transplant (graft loss) (11 studies, 1053 patients: RR 0.88, 95% CI 0.67 to 1.17; I² = 0%; moderate certainty of evidence). Compared with placebo, usual care, or no treatment, antioxidants had little to no effect on the slope of urinary albumin/creatinine ratio (change in UACR) (7 studies, 1286 patients: MD -0.04 mg/mmol, 95% CI -0.55 to 0.47; I² = 37%; very low certainty of evidence) but the evidence is very uncertain. Antioxidants probably reduced the progression to kidney failure (10 studies, 3201 patients: RR 0.65, 95% CI 0.41 to 1.02; I² = 41%; moderate certainty of evidence), may improve the slope of estimated glomerular filtration rate (change in eGFR) (28 studies, 4128 patients: MD 3.65 mL/min/1.73 m², 95% CI 2.81 to 4.50; I² = 99%; low certainty of evidence), but had uncertain effects on the slope of serum creatinine (change in SCr) (16 studies, 3180 patients: MD -13.35 µmol/L, 95% CI -23.49 to -3.23; I² = 98%; very low certainty of evidence). Possible safety concerns are an observed increase in the risk of infection (14 studies, 3697 patients: RR 1.30, 95% CI 1.14 to 1.50; I² = 3%; moderate certainty of evidence) and heart failure (6 studies, 3733 patients: RR 1.40, 95% CI 1.11 to 1.75; I² = 0; moderate certainty of evidence) among antioxidant users. Results of studies with a low risk of bias or longer follow-ups generally were comparable to the main analyses.

AUTHORS' CONCLUSIONS

We found no evidence that antioxidants reduced death or improved kidney transplant outcomes or proteinuria in patients with CKD. Antioxidants likely reduce cardiovascular events and progression to kidney failure and may improve kidney function. Possible concerns are an increased risk of infections and heart failure among antioxidant users. However, most studies were of suboptimal quality and had limited follow-up, and few included people undergoing dialysis or kidney transplant recipients. Furthermore, the large heterogeneity in interventions hampers drawing conclusions on the efficacy and safety of individual agents.

Vitamin E Treatment Improves the Antioxidant Capacity of Patients Receiving Dialysis: A Systematic Review and Meta-Analysis

SCOPE

To summarize the effect of vitamin E-coated dialyzer membranes (VEMs) treatment or oral vitamin E intake on antioxidant molecules, such as superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), and total antioxidant level in patients receiving dialysis.

METHODS AND RESULTS

A literature search of PubMed, Embase, CNKI, and the Cochrane Library databases is performed from inception to July 1, 2023, with no language nor country restrictions. Twenty-four experimental studies involving 512 patients undergoing dialysis are selected for meta-analysis. The levels of antioxidant markers in the blood of patients receiving hemodialysis (HD) improve with long-term VEMs treatment (p = 0.016). According to the findings of each antioxidant index, there is a significant increase in the levels of erythrocyte-derived SOD (p = 0.047), CAT (p = 0.029), and plasma-derived total antioxidant level (p < 0.001). The antioxidant marker levels in patients receiving HD are significantly increased by oral vitamin E intake (p < 0.001). Erythrocyte-derived SOD (p = 0.003), GPX (p < 0.001), and CAT (p = 0.001) substantially improves after 2-6 months of intervention with oral vitamin E preparation. The antioxidant index of patients receiving peritoneal dialysis (PD) is unaffected by oral vitamin E treatment (p = 0.945).

CONCLUSION

Vitamin E therapy has a favorable effect on the retention of antioxidant compounds in patients undergoing dialysis.

Effects of omega-3 supplementation on serum albumin, pre-albumin and the CRP/albumin ratio in hospitalized patients: a systematic review and meta-analysis

CONTEXT

Low serum albumin and pre-albumin concentrations are associated with edema, infection, thrombosis, heart failure, and mortality.

OBJECTIVE

This comprehensive systematic review and meta-analysis of clinical trials was conducted to summarize the available findings on the impact of omega-3 supplementation on albumin, pre-albumin, and the C-reactive protein/albumin ratio in hospitalized patients.

DATA SOURCES

PubMed, Web of Science, Scopus, and Google Scholar databases were searched from January 1990 to October 2021.

DATA EXTRACTION

Extracted data from 50 randomized controlled trials (RCTs) with a total number of 3196 participants were analyzed using the random-effects model. The dose-dependent effect was also evaluated.

DATA ANALYSIS

Oral omega-3 supplementation significantly increased serum albumin concentrations in patients with cancer (weighted mean difference [WMD]: 0.19; 95% CI: 0.05, 0.33, P= 0.006), patients on dialysis (WMD: 0.14; 95% CI: 0.01, 0.28, P= 0.042), and those with hypoalbuminemia (WMD: 0.38; 95% CI: 0.03, 0.72, P = 0.033); however, there was no significant effect among patients with gastrointestinal or hepatologic diseases. Moreover, each 1000 mg/day increase in oral omega-3 supplementation resulted in elevated serum albumin levels in cancer patients (WMD: 0.15; 95% CI: 0.07, 0.24, P < 0.001). In addition, a favorable effect of oral omega-3 supplementation on pre-albumin levels was observed among patients with cancer (WMD: 33.87; 95% CI: 12.34, 55.39, P = 0.002). A similar significant effect of parenteral omega-3 supplementation on pre-albumin concentrations was seen among those with gastrointestinal and hepatologic diseases as well (WMD: 23.30; 95% CI: 13.58, 33.03, P < 0.001). No significant effect of oral omega-3 supplementation on the CRP/albumin ratio was found.

CONCLUSIONS

Overall, omega-3 fatty acids supplementation resulted in a favorable change in serum albumin and pre-albumin concentrations in hospitalized patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021285704.

Beneficial Effects of Vitamin E Supplementation on Endothelial Dysfunction, Inflammation, and Oxidative Stress Biomarkers in Patients Receiving Hemodialysis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Inflammation and oxidative stress are closely related to cardiovascular complications and atherosclerosis, and have the potential to lead to an increase in death in patients receiving hemodialysis. Vitamin E has antioxidant and anti-inflammatory properties. We conducted a systematic review and meta-analysis to assess the effects of vitamin E supplementation on endothelial dysfunction, inflammation, and oxidative stress biomarkers in adult patients receiving hemodialysis. We searched the MEDLINE, EMBASE, Web of Science, and Cochrane Library databases and identified randomized controlled trials of adult patients receiving hemodialysis until 30 August 2021. A total of 11 trials with 491 randomized patients were included. The pooled data indicated that vitamin E supplementation significantly decreased intercellular adhesion molecule-1 [standardized mean difference (SMD): -1.35; 95% confidence interval (CI): -2.57, -0.13; p = 0.03, I2 = 89%], vascular cell adhesion molecule-1 (SMD: -1.08; 95% CI: -2.05, -0.11; p = 0.03, I2 = 81%), C-reactive protein (SMD: -0.41; 95% CI: -0.75, -0.07; p = 0.02, I2 = 64%), and malondialdehyde (SMD: -0.76; 95% CI: -1.26, -0.25; p = 0.003, I2 = 77%) levels, but not interleukin-6 levels compared to those in the control group. Our results suggest that vitamin E supplementation may help alleviate oxidative stress and both vascular and systemic inflammation in patients receiving hemodialysis.

Effects of Omega-3 Fatty Acid Intake in Patients Undergoing Dialysis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective: Fish oil supplementation has been shown to be beneficial for hemodialysis (HD) patients. The aim of this study was to evaluate the efficacy and safety of omega-3 fatty acid supplementation or dietary adjustment in dialysis patients.Methods: A systematic literature search was performed to identify relevant randomized controlled trials (RCTs) to study the effects of omega-3 supplementation on dialysis patients. The variables of interest included the levels of blood lipids, inflammatory indicators, proteins, parathyroid hormone (PTH), gastrointestinal adverse reactions, and all-cause mortality. The mean differences (MDs) and 95% confidence intervals (CIs) were calculated, and heterogeneity was assessed with the I² test. Subgroup and sensitivity analyses were performed to identify potential sources.Results: The systematic review included 49 RCTs and evaluated the efficacy and safety of omega-3 fatty acid supplementation in dialysis patients. Data synthesis showed that compared with the control group, the group receivingomega-3 supplementation exhibited significantly decreased serum triglyceride (TG) levels, decreased C-reactive protein (CRP) and TNF-alpha levels, increased hemoglobin levels, reduced serum phosphorus levels, increased PTH levels, and increased gastrointestinal adverse reactions to a certain extent. Furthermore, there was no effect on the blood total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), albumin or calcium levels and all-cause mortality.Conclusion: Omega-3 fatty acid supplementation is related to a reduction in serum TG, LDL and inflammation index levels and has few adverse reactions. Therefore, omega-3 fatty acid supplementation may be a useful nutrition therapy for dialysis patients.

The effect of fish oil on inflammation markers in adult patients undergoing hemodialysis: A meta-analysis

OBJECTIVE

This meta-analysis was to assess the effect of fish oil supplementation on inflammation markers in adult patients receiving hemodialysis.

METHODS

CENTRAL, EMBASE, MEDLINE databases were searched from inception to 10 April 2020. Two authors independently searched, selected, and screened the literature. The pooled results are represented by WMD or SMD with 95% confidence intervals. Subgroup analysis and meta-regression were used to explore sources of heterogeneity, and sensitivity analysis was used to assess the robustness of the pooled results. Funnel plots were used to assess publication bias.

RESULTS

Eleven RCT (randomized control trials) studies were included. The pooled results showed that fish oil supplementation caused a significant reduction of the CRP(C-reactive protein) level (random model: WMD, -3.36, 95%CI: -5.46 to -1.26, P = .002), especially in patients with baseline CRP ≥ 5 mg/L (random model: WMD, -4.43, 95%CI: -6.10 to -2.76, P = .00001, I²  = 41%). Meta-regression analyses showed that CRP baseline level (CRP < 5 mg/L) was the main source of heterogeneity (P = .036). Sensitive analyses revealed that the result was hardly changed. Fish oil supplementation might not reduce the level of IL-6 (random model: WMD, -2.26, 95%CI: -19.61 to 15.09, P = .80) in four studies or the level of TNF-α (random model: SMD, -2.51, 95%CI: -6.08 to 1.06, P = .17) in three studies.

CONCLUSIONS

Fish oil supplementation could reduce the level of CRP in hemodialysis patients, especially in patients with CRP ≥ 5 mg/L, but had no effects on IL-6 and TNF-α.

Effect of Omega-3 Fatty Acid Alone and in Combination with Proprietary Chromium Complex on Endothelial Function in Subjects with Metabolic Syndrome: A Randomized, Double-Blind, Parallel-Group Clinical Study

Metabolic syndrome (MetS) represents a cluster of metabolic abnormalities that include hypertension, central obesity, insulin resistance, and dyslipidemia and is strongly associated with an increased risk of diabetes, cardiovascular diseases (CVD), and all-cause mortality. Early diagnosis is important to employ lifestyle and risk factor modification. Existing therapies are limited. Studies report positive effect of omega-3 fatty acids (ω-3FA) on symptoms of metabolic syndrome. The present study was undertaken to evaluate the effect of ω-3FA alone and in combination with proprietary chromium complex (PCC) on endothelial function in subjects with metabolic syndrome. In this randomized, double-blind, parallel-group study, subjects were enrolled into the study after ethics committee (EC) approval and informed consent. Eligible subjects were randomized to receive ω-3FA concentrate 2000 mg (Group A-18 subjects), ω-3FA concentrate 2000 mg + PCC200 mcg (Group B-19 subjects), and ω-3FA concentrate 2000 mg + PCC400 mcg (Group C-21 subjects) daily for 12 weeks. Endothelial dysfunction as measured by reflection index (RI), biomarkers of oxidative stress (NO, MDA, and glutathione), and inflammation (hsCRP, endothelin-1, ICAM-1, and VCAM-1) were evaluated at baseline, 4, and 12 weeks. Lipid-profile and platelet-aggregation tests were performed at baseline and 12 weeks. Adverse drug reactions were recorded. Compliance was assessed by pill count method. GraphPad Prism8 was used for statistical analysis. Significant changes were seen from 4 weeks onwards in all the parameters evaluated. Significant improvement in RI% (mean ± SD = -2.56 ± 0.77 to -3.27 ± 0.67-group A, -2.33 ± 0.76 to 4.72 ± 0.79-group B; -2.39 ± 1.13 to 6.46 ± 1.00-group C) was seen at 12 weeks. Significant improvement in biomarkers of oxidative stress and inflammation was seen with all the treatment groups. Similarly, significant improvement in lipid profile was seen in group B and group C, while group A showed change in HDL, VLDL, and TG. Group C demonstrated the best response in the parameters evaluated. Three patients in group C reported gastrointestinal adverse events, which resolved spontaneously; none stopped the therapy. So, the addition of PCC to ω-3FA may prove to have beneficial effect in reducing cardiovascular morbidity in MetS patients.

Effect of nutritional support on nutritional status and inflammation in malnourished patients undergoing maintenance hemodialysis

INTRODUCTION

Protein energy wasting/malnutrition is a strong predictor of morbidity and mortality in patients on maintenance hemodialysis (MHD). We aimed to compare the effects of oral and/or intradialytic parenteral nutrition (IDPN) support on nutritional and inflammatory parameters in malnourished patients with MHD.

METHODS

This is an observational study of 56 malnourished patients on MHD. We offered combined oral nutritional support (ONS) and IDPN for 12 months to all patients. Depending on patient choices for treatment, they were classified into four groups: group 1 (ONS only), group 2 (IDPN only), group 3 (both ONS and IDPN), and group 4 (patients who refused artificial nutrition support and only followed dietary advice). Normalized protein catabolic rate (nPCR), malnutrition inflammation score (MIS), and body composition (fat mass [FM], muscle mass [MM]) were assessed monthly.

FINDINGS

The mean serum albumin levels of groups 2 and 3 significantly increased with the intervention, whereas that of group 4 significantly decreased. The mean nPCR levels of groups 2 and 3 significantly increased. Group 3 had the most significant positive change in serum albumin and nPCR levels. Mean serum C-reactive protein (CRP) levels of groups 1, 2, and 3 decreased, whereas those of group 4 increased. A ∆ in CRP was only identified in group 3. The MIS of groups 1, 2, and 3 significantly decreased whereas that of group 4 significantly increased. The ∆% in FM was 1.1, 1.9, 9.1, and -2.9 for groups 1, 2, 3, and 4, respectively, and that in MM was -0.6, 4.4, 6.9, and -7.9 for groups 1, 2, 3, and 4, respectively.

DISCUSSION

Compared to monotherapy or nutritional counseling, the choice of ONS plus IDPN is associated with improved nutritional status and decreased inflammation in malnourished patients on MHD. Nonetheless, interventional studies must be conducted to confirm these observations.

The effects of vitamin E supplementation on malondialdehyde as a biomarker of oxidative stress in haemodialysis patients: a systematic review and meta-analysis

Background

Haemodialysis (HD) patients tend to have higher levels of oxidative stress (OS), associated with increased morbidity and premature mortality, compared to the general population. Levels of malondialdehyde (MDA), a biomarker of OS, are reduced by the antioxidant properties of vitamin E (VE) but outcomes from randomised control trials of VE supplementation on MDA in HD patients have been inconsistent.

Methods

We undertook a systematic review and meta-analysis of adult HD patients from VE supplementation studies with measures of MDA. The following search criteria of MEDLINE and EMBASE were considered from inception to January 2020: ‘dialysis’ AND ‘Vitamin E OR tocopherol’ AND ‘malondialdehyde OR MDA’. Two reviewers independently extracted study data and assessed risk of bias. Mean MDA levels and standard deviation were determined before and after VE supplementation. Standardised mean difference (SMD) and standard error were calculated as the within person difference and units of measure were not consistently recorded across all studies. The SMD were pooled using random effects meta-analysis.

Results

The SMD of MDA levels from 18 comparisons was significantly lower in HD patients following VE supplementation (− 1.55; confidence interval: − 2.17 to − 0.94, P < 0.00001). There were significant levels of heterogeneity between studies (I² value = 91%; P < 0.00001) with evidence of potential publication bias toward smaller studies.

Conclusions

Our findings support the use of VE to reduce the effects of OS in HD patients although high levels of heterogeneity and variation in the methodological approaches used by some studies highlight the need for further investigation.

The efficacy of L-carnitine in improving malnutrition in patients on maintenance hemodialysis: a meta-analysis

The improvement of malnutrition with levocarnitine in maintenance hemodialysis (MHD) patients is controversial. We performed a meta-analysis to evaluate the efficacy of levocarnitine in improving malnutrition in MHD patients. We performed a literature search for relevant articles related to the treatment of malnutrition by L-carnitine in MHD patients in PubMed, Embase, Web of Science, China National Knowledge Infrastructure, and Wanfang databases. We set the publication dates from 1950 to July 2019. The levels of albumin, prealbumin, total protein, and transferrin before and after treatment were used for assessing malnutrition. Twenty-seven studies were included in the present analysis. The results of the random effects model indicated that L-carnitine treatment improved the albumin level in patients on MHD patients. The pooled standardized mean difference of albumin level was 2.51 (95% confidence interval (CI): 2.13-2.90, P<0.001). The pooled total protein level was 3.83 (95% CI: 2.41-5.24, P = 0.000) and the pooled transferrin level was 0.35 (95% CI: 0.18-0.52, P = 0.000). Significant differences were observed with the total protein and transferrin levels. The results indicated that levocarnitine significantly improved the prealbumin level in patients on MHD. The pooled prealbumin level was 70.86 (95% CI: 42.99-98.73, P = 0.000). No publication bias was detected (P>0.05). The present meta-analysis indicated that L-carnitine can have a favorable effect on malnutrition biomarkers in patients on MHD, including the increase in albumin, total protein, transferrin, and prealbumin levels. The L-carnitine could be an option for treatment of MHD patients.

Circulating fatty acid profiles are associated with protein energy wasting in maintenance hemodialysis patients: a cross-sectional study

The metabolic impact of circulating fatty acids (FAs) in patients requiring hemodialysis (HD) is unknown. We investigated the associations between plasma triglyceride (TG) FAs and markers of inflammation, insulin resistance, nutritional status and body composition. Plasma TG-FAs were measured using gas chromatography in 341 patients on HD (age = 55.2 ± 14.0 years and 54.3% males). Cross-sectional associations of TG-FAs with 13 markers were examined using multivariate linear regression adjusted for potential confounders. Higher levels of TG saturated fatty acids were associated with greater body mass index (BMI, r = 0.230), waist circumference (r = 0.203), triceps skinfold (r = 0.197), fat tissue index (r = 0.150), serum insulin (r = 0.280), and homeostatic model assessment of insulin resistance (r = 0.276), but lower malnutrition inflammation score (MIS, r =  − 0.160). Greater TG monounsaturated fatty acid levels were associated with lower lean tissue index (r =  − 0.197) and serum albumin (r =  − 0.188), but higher MIS (r = 0.176). Higher levels of TG n-3 polyunsaturated fatty acids (PUFAs) were associated with lower MIS (r =  − 0.168) and interleukin-6 concentrations (r =  − 0.115). Higher levels of TG n-6 PUFAs were associated with lower BMI (r =  − 0.149) but greater serum albumin (r = 0.112). In conclusion, TG monounsaturated fatty acids were associated with poor nutritional status, while TG n-3 PUFAs were associated with good nutritional status. On the other hand, TG saturated fatty acids and TG n-6 PUFAs had both favorable and unfavorable associations with nutritional parameters.

Doping Polysulfone Membrane with Alpha-Tocopherol and Alpha-Lipoic Acid for Suppressing Oxidative Stress Induced by Hemodialysis Treatment

The reduction of free radicals by bioactive membranes used for hemodialysis treatment is an important topic due to the constant rise of oxidative stress-associated cardiovascular mortality by hemodialysis patients. Therefore, it is urgent to find an effective solution that helps to solve this problem. Polysulfone membranes enriched with α-lipoic acid, α-tocopherol, and with both components are fabricated by spin coating. The antioxidant properties of these membranes are evaluated in vitro by determining the lipid-peroxidation level and the total antioxidant status of the blood plasma. The biocompatibility is assessed by quantifying the protein adsorption, platelet adhesion, complement activation, and hemolytic effect. All types of membranes show in vitro antioxidant activity and a trend to reduce oxidative stress in vivo; the best results show membranes prepared with a combination of both compounds and prove to be nonhemolytic and hemocompatible. Moreover, the membrane specific separation ability for the main waste products is not affected by antioxidants incorporation.

Evaluation of the Effect of Fish Oil Alone and in Combination with a Proprietary Chromium Complex on Endothelial Dysfunction, Systemic Inflammation and Lipid Profile in Type 2 Diabetes Mellitus - A Randomized, Double-Blind, Placebo-Controlled Clinical Study

PURPOSE

This study was conducted to evaluate the effectiveness of fish oil alone and with an adjunct, a proprietary chromium complex (PCC), on cardiovascular parameters - endothelial dysfunction, lipid profile, systemic inflammation and glycosylated hemoglobin - in a 12-week randomized, double-blind, placebo-controlled clinical study in type 2 diabetes mellitus subjects.

PATIENTS AND METHODS

In this randomized, double-blind, parallel group study, 59 subjects in three groups completed the study: Group A, fish oil 2000 mg; Group B, fish oil 2000 mg + PCC 10 mg (200 µg of Cr³⁺); and Group C, fish oil 2000 mg + PCC 20 mg (400 µg of Cr³⁺) daily for 12 weeks (2000 mg of fish oil contained 600 mg of eicosapentaenoic acid [EPA] and 400 mg of docosahexaenoic acid [DHA], the omega-3 fatty acids). Endothelial function, by estimating reflection index (RI), biomarkers of oxidative stress (nitric oxide [NO], malondialdehyde [MDA], glutathione [GSH]) and inflammatory biomarkers (high-sensitivity C-reactive protein [hsCRP], intercellular adhesion molecule-1 [ICAM-1], vascular cell adhesion molecule-1 [VCAM-1], endothelin-1) were evaluated at baseline, and 4 and 12 weeks. Lipid profile, platelet aggregation and glycosylated hemoglobin [HbA1c) were tested at baseline and 12 weeks. Any reported adverse drug reactions were recorded. Statistical analysis was performed using GraphPad Prism 8.

RESULTS

The present study shows that fish oil by itself, at a dose of 2000 mg (600 mg of EPA + 400 mg of DHA) per day, led to significant, but only modest, improvement in cardiovascular parameters (RI from -2.38±0.75 to -3.92±0.60, MDA from 3.77±0.16 to 3.74±0.16 nM/mL, NO from 30.60±3.18 to 32.12±3.40 µM/L, GSH from 568.93±5.91 to 583.95±6.53 µM/L; p≤0.0001), including triglyceride levels. However, when PCC was added to fish oil, especially at the 20 mg dose, there were highly significant improvements in all the parameters tested (RI from -2.04±0.79 to -8.73±1.36, MDA from 3.67±0.39 to 2.89±0.34 nM/mL, NO from 28.98±2.93 to 40.01±2.53 µM/L, GSH from 553.82±8.18 to 677.99±10.19 µM/L; p≤0.0001), including the lipid profile. It is noteworthy that the triglycerides were decreased significantly by addition of 20 mg of PCC although the dose of fish oil was only 2 g/day and the baseline triglyceride levels were only about 200 mg/dL. Fish oil alone did not significantly decrease the HbA1c, whereas the addition of 20 mg of PCC did.

CONCLUSION

Addition of PCC, especially at 20 mg dose, significantly improves the efficacy of fish oil in addressing cardiovascular risk factors compared to fish oil given alone.

Malnutrition impairs mitochondrial function and leukocyte activation

BACKGROUND

The aim of this study was to evaluate markers of inflammation, oxidative stress and endothelial function in a disease-related malnutrition (DRM) outpatient population.

METHODS

For this cross-sectional study, a total of 83 subjects were included and clustered in 3 groups: 34 with normonutrition (NN), 21 with DRM without inflammation (DRM-I) and 28 with DRM and inflammation (DRM + I). Nutritional diagnosis was conducted for all subjects according to ASPEN. Biochemical parameters, proinflammatory cytokines, reactive oxygen species production, glutathione, mitochondrial membrane potential, oxygen consumption, adhesion molecules and leukocyte-endothelium interactions were evaluated.

RESULTS

DRM + I patients showed lower albumin, prealbumin, transferrin, and retinol-binding protein levels with respect to the NN group (p < 0.05), differences that were less noticeable in the DRM-I group. DRM + I was associated with a significant increase in hsCRP and IL6 vs the NN and DRM-I groups, and TNFα was increased in both DRM vs NN. DRM was characterised by increased oxidative stress, which was marked by a significant increase in ROS levels and a decrease in mitochondrial membrane potential in the DRM + I group. An evident reduction in mitochondrial oxygen consumption and glutathione concentration was observed in both DRM groups, and was accompanied by increased leukocyte adhesion and adhesion molecules and decreased rolling velocity in the DRM + I group. Furthermore, percentage of weight loss was negatively correlated with albumin, prealbumin, transferrin, O₂ consumption, glutathione and leukocyte rolling velocity, and positively correlated with hsCRP, IL6, TNFα, ROS, leukocyte adhesion, and VCAM-1.

CONCLUSIONS

Our results show that DRM is associated with oxidative stress and an inflammatory state, with a deterioration of endothelial dysfunction in the DRM + I population.

Omega-3 fatty acids supplementation and oxidative stress parameters: A systematic review and meta-analysis of clinical trials

Omega-3 fatty acids (omega-3 FAs) supplementation effects on oxidants and antioxidants are always controversial. Oxidative stress (OS) is one of the major mechanisms that contribute to the pathogenesis of several chronic diseases. The present systematic review and meta-analysis aimed to summarize the finding of randomized clinical trials (RCTs) examining the effects of omega-3 FAs on OS markers. Five databases including PubMed, Embase, Scopus, Web of science, and Cochrane were searched up to May 5th, 2019 with no language restriction. RCTs included if they compared OS indices among subjects who received omega-3 FAs supplements and subjects who supplemented with placebo. To estimate the effects of omega-3 FAs supplementation, standardized mean difference (SMD) with 95% confidence intervals (95% CI) were pooled using random effects model. Of 5,887 publications, 39 trials involving 2,875 participants were included for the meta-analysis. The pooled analysis of data indicated that omega-3 FAs significantly increased serum total antioxidant capacity (TAC) (SMD: 0.48, 95% CI: 0.23, 0.72, P< 0.001; I²= 60%), glutathione peroxidase (GPx) (SMD: 0.73, 95% CI: 0.30, 1.16, P= 0.001; I²= 83%) activity and decreased malondialdehyde (MDA) (SMD= -0.42, 95% CI: -0.62, -0.21; P < 0.001; I²= 74%) compared to the placebo group. However, the effects of omega-3 FAs on nitric oxide (NO) (SMD: -0.17 , 95% CI: -0.77, 0.43, P = 0.57; I²= 91%), reduced glutathione (GSH) (SMD= 0.23, 95% CI= -0.17, 0.64, P= 0.25; I²= 75%), superoxide dismutase (SOD) (0.12 , 95% CI: -0.40, 0.65, P= 0.64; I²= 89%) and catalase (CAT) (0.16, 95% CI: -0.33, 0.65, P= 0.52; I²= 75%,) activities was not significant. Supplementation with omega-3 FAs significantly improves MDA, TAC levels, and GPx activity. Thus, omega-3 FAs can be mentioned as enhancer factors in antioxidant defense against reactive oxygen species (ROS).

The effect of omega-3 and vitamin E on oxidative stress and inflammation: Systematic review and meta-analysis of randomized controlled trials

Background: Several studies have investigated the effect of omega-3 fatty acids and vitamin E on oxidative stress and inflammation, but their findings are inconsistent. The aim of this meta-analysis is to elucidate the overall effects of co-supplementation with omega-3 fatty acids and vitamin E on oxidative stress and inflammation. Methods: We searched titles, abstracts, and keywords of relevant articles indexed in PubMed, ISI, Scopus, and Google Scholar databases up to December 2018 to identify eligible RCT studies. Random effects model was used to estimate the pooled effect of co-supplementation with omega-3 fatty acids and vitamin E on oxidative stress and inflammation. Results: Overall, 7 RCTs with 504 participants were included in this meta-analysis. We found that co-supplementation with omega-3 fatty acids and vitamin E decreased hs-CRP (weighed mean difference (WMD) = -2.15 mg/L; 95% CI: -3.40, -0.91 mg/L; P < 0.001) concentrations and increased total antioxidant capacity (TAC) (WMD = 92.87 mmol/L; 95% CI: 31.97, 153.77 mmol/L; P = 0.03), and nitric oxide levels (NO) (WMD: 6.95 μmol/L; 95% CI: 3.86, 10.04, P < 0.001) compared with control group. Omega-3 fatty acids and vitamin E had no significant effect on malondialdehyde (MDA) (WMD: 1.54 mmol/L; 95% CI: -1.29, 4.36; P = 0.196), and glutathione (GSH) (WMD: 20.87 mmol/L; 95% CI: -20.04, 61.6, P = 0.31) levels. Conclusion: The present meta-analysis found that omega-3 fatty acids and vitamin E co-supplementation significantly decreased hs-CRP and increased NO and TAC, although it had no significant effect on MDA and GSH.

The Effect of Omega-3 Supplementation on Serum Levels of Inflammatory Biomarkers and Albumin in Hemodialysis Patients: A Systematic Review and Meta-analysis

This systematic review and meta-analysis were performed to evaluate the effect of omega-3 supplementation on serum levels of inflammatory biomarkers (C-reactive protein [CRP], high-sensitivity CRP [hs-CRP], tumor necrosis factor-alpha, interleukin-6) and albumin in patients on hemodialysis. A literature search was performed in MEDLINE, Cochrane Central Register of Controlled Trials, PubMed, EMBASE, Web of Science, and Google Scholar. Randomized controlled trials that evaluated the effect of omega-3 supplementation versus placebo were selected. Eight randomized controlled trials comprising 371 patients on hemodialysis were included. According to our results, omega-3 supplementation significantly decreased serum levels of CRP (standardized mean difference [SMD]: -1.95 mg/Dl; 95% confidence interval [CI]: -3.09, -0.80) and hs-CRP (SMD: -2.09; 95% CI: -3.62, -0.56) but did not significantly improve albumin (SMD: 0.91; 95% CI: -0.78, 2.59), tumor necrosis factor-alpha (SMD: -1.51; 95% CI: -3.24, 0.22), and interleukin-6 (SMD: 0.72, 95% CI: -0.56, 1.99). We concluded that omega-3 supplementation leads to a significant decrease in serum levels of CRP and hs-CRP.

Efficacy of Polyunsaturated Fatty Acids on Inflammatory Markers in Patients Undergoing Dialysis: A Systematic Review with Network Meta-Analysis of Randomized Clinical Trials

The effects of polyunsaturated fatty acids (PUFAs) on inflammatory markers among patients receiving dialysis have been discussed for a long time, but previous syntheses made controversial conclusion because of highly conceptual heterogeneity in their synthesis. Thus, to further understanding of this topic, we comprehensively gathered relevant randomized clinical trials (RCTs) before April 2019, and two authors independently extracted data of C-reactive protein (CRP), high-sensitivity C-reactive protein (hs-CRP), and interleukin-6 (IL-6) for conducting network meta-analysis. Eighteen eligible RCTs with 962 patients undergoing dialysis were included in our study. The result showed that with placebo as the reference, PUFAs was the only treatment showing significantly lower CRP (weighted mean difference (WMD): −0.37, 95% confidence interval (CI): −0.07 to −0.68), but the CRP in PUFAs group was not significantly lower than vitamin E, PUFAs plus vitamin E, or medium-chain triglyceride. Although no significant changes were noted for hs-CRP and IL-6 levels, PUFAs showed the best ranking among treatments according to surface under the cumulative ranking. Therefore, PUFAs could be a protective option for patients receiving dialysis in clinical practice.

Efficacy of Nutritional Interventions on Inflammatory Markers in Haemodialysis Patients: A Systematic Review and Limited Meta-Analysis

Low-grade chronic inflammation is prevalent in patients undergoing haemodialysis (HD) treatment and is linked to the development of premature atherosclerosis and mortality. The non-pharmacological approach to treat inflammation in HD patients through nutritional intervention is well cited. We aimed to assess the efficacy of different nutritional interventions at improving inflammatory outcomes in HD patients, based on markers such as C-reactive protein (CRP), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α). We searched PubMed, Cochrane Library, and Embase for randomized controlled trials (RCT) published before June 2017. Inclusion criteria included RCTs on adult patients on maintenance HD treatment with duration of nutritional interventions for a minimum 4 weeks. Risk of bias was assessed using the Jadad score. In total, 46 RCTs experimenting different nutritional interventions were included in the review and categorized into polyphenols rich foods, omega-3 fatty acids, antioxidants, vitamin D, fibres, and probiotics. Meta-analyses indicated significant reduction in CRP levels by omega-3 fatty acids (Random model effect: -0.667 mg/L, p < 0.001) and vitamin E (fixed model effect: -0.257 mg/L, p = 0.005). Evidence for other groups of nutritional interventions was inconclusive. In conclusion, our meta-analysis provided evidence that omega-3 fatty acids and vitamin E could improve inflammatory outcomes in HD patients.

Update on the Impact of Omega 3 Fatty Acids on Inflammation, Insulin Resistance and Sarcopenia: A Review

Elderly and patients affected by chronic diseases face a high risk of muscle loss and impaired physical function. Omega 3 fatty acids (FA) attenuate inflammation and age-associated muscle loss, prevent systemic insulin resistance and improve plasma lipids, potentially impacting on sarcopenia. This paper aims to review recent randomized clinical studies assessing the effects a chronic omega 3 FA supplementation on inflammatory and metabolic profile during conditions characterized by sarcopenia (aging, insulin resistance, type 2 diabetes, chronic renal failure). A comprehensive search of three online databases was performed to identify eligible trials published between 2012 and 2017. A total of 36 studies met inclusion criteria. Omega 3 FA yielded mixed results on plasma triglycerides in the elderly and no effects in renal patients. No changes in systemic insulin resistance were observed. Inflammation markers did not benefit from omega 3 FA in insulin resistant and in renal subjects while decreasing in obese and elderly. Muscle related parameters improved in elderly and in renal patients. In conclusion, in aging- and in chronic disease-associated sarcopenia omega 3 FA are promising independently of associated anabolic stimuli or of anti-inflammatory effects. The evidence for improved glucose metabolism in insulin resistant and in chronic inflammatory states is less solid.

Factors Associated with Frailty and Its Trajectory among Patients on Hemodialysis

BACKGROUND AND OBJECTIVES

Frailty is common among patients on hemodialysis and associated with adverse outcomes. However, little is known about changes in frailty over time and the factors associated with those changes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

To address these questions, we examined 762 participants in the A Cohort to Investigate the Value of Exercise/Analyses Designed to Investigate the Paradox of Obesity and Survival in ESRD cohort study, among whom frailty was assessed at baseline and 12 and 24 months. We used ordinal generalized estimating equations analyses and modeled frailty (on a scale from zero to five possible components) and death during follow-up.

RESULTS

The mean frailty score at baseline was 1.9, and the distribution of frailty scores was similar at each evaluation. However, most participants' scores changed, with patients improving almost as often as worsening (overall change, 0.2 points per year; 95% confidence interval, 0.1 to 0.3). Hispanic ethnicity (0.6 points per year; 95% confidence interval, 0.0 to 1.1) and diabetes (0.7 points per year; 95% confidence interval, 0.3 to 1.0) were associated with higher frailty scores and higher serum albumin concentration with lower frailty scores (-1.1 points per g/dl; 95% confidence interval, -1.5 to -0.7). In addition, patients whose serum albumin increased over time were less likely to become frail, with each 1-g/dl increase in albumin associated with a 0.4-point reduction in frailty score (95% confidence interval, -0.80 to -0.05). To examine the underpinnings of the association between serum albumin and frailty, we included serum IL-6, normalized protein catabolic rate, and patient self-report of hospitalization within the last year in a second model. Higher IL-6 and hospitalization were statistically significantly associated with worse frailty at any point and worsening frailty over time, whereas normalized protein catabolic rate was not independently associated with frailty.

CONCLUSIONS

There was substantial year to year variability in frailty scores, with approximately equal numbers of patients improving and worsening. Markers of inflammation and hospitalization were independently associated with worsening frailty. Studies should examine whether interventions to address inflammation or posthospitalization rehabilitation can improve the trajectory of frailty.

The effects of omega-3 fatty acids and vitamin E co-supplementation on clinical and metabolic status in patients with Parkinson's disease: A randomized, double-blind, placebo-controlled trial

The current research was performed to evaluate the effects of omega-3 fatty acids and vitamin E co-supplementation on clinical signs and metabolic status in people with Parkinson's disease (PD). This randomized double-blind placebo-controlled clinical trial was conducted in 60 patients with PD. Participants were randomly assigned into two groups to receive either 1000 mg omega-3 fatty acids from flaxseed oil plus 400 IU vitamin E supplements (n = 30) or placebo (n = 30) for 12 weeks. Unified Parkinson's disease rating stage (UPDRS) were recorded at baseline and the after 3-month intervention. After 12 weeks' intervention, compared with the placebo, omega-3 fatty acids and vitamin E co-supplementation led to a significant improve in UPDRS (-3.3 ± 10.0 vs. +4.4 ± 14.9, P = 0.02). Furthermore, co-supplementation decreased high-sensitivity C-reactive protein (hs-CRP) (-0.3 ± 0.6 vs. +0.3 ± 0.3 μg/mL, P < 0.001), and increased total antioxidant capacity (TAC) (+65.2 ± 68.7 vs. +16 ± 52.4 μmol/L, P = 0.003) and glutathione (GSH) concentrations (+41.4 ± 80.6 vs. -19.6 ± 55.9 μmol/L, P = 0.001) compared with the placebo. Additionally, co-supplementation meaningfully decreased insulin (-2.1 ± 4.9 vs. +1.4 ± 6.2 μIU/mL, P = 0.01), homeostasis model of assessment-estimated insulin resistance (-0.7 ± 1.8 vs.+0.3 ± 1.6, P = 0.02) and Beta cell function (-5.9 ± 13.9 vs. +5.7 ± 25.5, P = 0.03), and increased quantitative insulin sensitivity check index (+0.009 ± 0.02 vs. -0.006 ± 0.03, P = 0.03) compared with the placebo. Overall, our study demonstrated that omega-3 fatty acids and vitamin E co-supplementation in people with PD had favorable effects on UPDRS, hs-CRP, TAC, GSH and markers of insulin metabolism.