The effects of omega-3 fatty acids supplementation on hemoglobin, hematocrit, and platelet levels of patients with ESRD condition undergoing dialysis

Background

Concomitant inflammation may boost the cardiovascular complications in end-stage renal disease (ESRD) patients undergoing hemodialysis (HD). Omega-3 fatty acids may have certain health benefits in HD patients. The aim of this study was to investigate the effects of omega-3 fatty acids supplementation on hematocrit (HCT), hemoglobin (HB) level and platelet (PLT) counts of HD patients.

Methods

A randomized controlled trial was conducted on HD patients at a private dialysis center in Rasht, Iran. Three omega-3 fatty acid supplement capsules (3 g/d) were administered daily for two months to patients in the intervention group (n = 55). The control group (n = 60) were given three placebo capsules containing medium chain triglyceride (MCT) oil, similar to the supplemental dose of the intervention group at the same period. Three parameters of HCT, HB and PLT were measured at baseline and after the intervention.

Results

The PLT count decreased in the intervention group compared to the control group (173.38 ± 74.76 vs. 227.68 ± 86.58 103/mm3, F = 4.83, P = 0.03). No significant change was found on the levels of HCT and HB parameters between the two groups after the intervention.

Conclusion

Omega-3 supplementation in HD patients may decrease the risk of forming blood clots in the blood vessels. Further studies are warranted.

Effect of Omega-3 Fatty Acids Supplementation on Homocysteine Level in Patients Undergoing Continuous Ambulatory Peritoneal Dialysis

Objective

One of the most common diseases with high morbidity and mortality rates is chronic kidney disease. Cardiovascular disease affects most patients with chronic kidney disorders, particularly patients undergoing dialysis; hence, appropriate prevention and management approaches are essential. This study aimed to evaluate the reduction of inflammatory biomarkers, especially homocysteine, by omega-3 fatty acids in peritoneal dialysis patients.

Methods

This study enrolled 60 peritoneal dialysis patients who met specified inclusion and exclusion criteria and were randomized to intervention or placebo groups. Omega-3 capsules were given at a dose of 3 g/d for 8 weeks. Inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP), homocysteine, albumin, and lipid profile measured before and after the study.

Findings

Results of this trial revealed that the levels of homocysteine, hs-CRP, and albumin did not change significantly during the study. Analysis of lipid profiles before and after intervention showed omega-3 has no significant effect on the level of total cholesterol or low-density lipoprotein cholesterol; However, the level of triglyceride reduced remarkably (P = 0.002). In addition, serum levels of high-density lipoprotein cholesterol increased at the end of the study (P < 0.001).

Conclusion

Omega-3 does not seem to be able to change the inflammatory markers significantly, particularly homocysteine. More extensive trials must be conducted to better understand the impact of omega-3 on inflammatory and nutritional markers, particularly in peritoneal dialysis patients.

Marine-derived n-3 fatty acids therapy for stroke

BACKGROUND

Currently, with stroke burden increasing, there is a need to explore therapeutic options that ameliorate the acute insult. There is substantial evidence of a neuroprotective effect of marine-derived n-3 polyunsaturated fatty acids (PUFAs) in animal models of stroke, leading to a better functional outcome.

OBJECTIVES

To assess the effects of administration of marine-derived n-3 PUFAs on functional outcomes and dependence in people with stroke.

SEARCH METHODS

We searched the Cochrane Stroke Trials Register (last searched 31 May 2021), the Cochrane Central Register of Controlled Trials (CENTRAL; 2021, Issue 5), MEDLINE Ovid (from 1948 to 31 May 2021), Embase Ovid (from 1980 to 31 May 2021), CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; from 1982 to 31 May 2021), Science Citation Index Expanded ‒ Web of Science (SCI-EXPANDED), Conference Proceedings Citation Index-Science - Web of Science (CPCI-S), and BIOSIS Citation Index. We also searched ongoing trial registers, reference lists, relevant systematic reviews, and used the Science Citation Index Reference Search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing marine-derived n-3 PUFAs to placebo or open control (no placebo) in people with a history of stroke or transient ischaemic attack (TIA), or both.

DATA COLLECTION AND ANALYSIS

At least two review authors independently selected trials for inclusion, extracted data, assessed risk of bias, and used the GRADE approach to assess the certainty of the body of evidence. We contacted study authors for clarification and additional information on stroke/TIA participants. We conducted random-effects meta-analysis or narrative synthesis, as appropriate. The primary outcome was efficacy (functional outcome) assessed using a validated scale, for example, the Glasgow Outcome Scale Extended (GOSE) dichotomised into poor or good clinical outcome, the Barthel Index (higher score is better; scale from 0 to 100), or the Rivermead Mobility Index (higher score is better; scale from 0 to 15). Our secondary outcomes were vascular-related death, recurrent events, incidence of other type of stroke, adverse events, quality of life, and mood.

MAIN RESULTS

We included 30 RCTs; nine of them provided outcome data (3339 participants). Only one study included participants in the acute phase of stroke (haemorrhagic). Doses of marine-derived n-3 PUFAs ranged from 400 mg/day to 3300 mg/day. Risk of bias was generally low or unclear in most trials, with a higher risk of bias in smaller studies. We assessed results separately for short (up to three months) and longer (more than three months) follow-up studies. Short follow-up (up to three months) Functional outcome was reported in only one pilot study as poor clinical outcome assessed with the GOSE (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.36 to 1.68, P = 0.52; 40 participants; very low-certainty evidence). Mood (assessed with the GHQ-30, lower score better) was reported by only one study and favoured control (mean difference (MD) 1.41, 95% CI 0.07 to 2.75, P = 0.04; 102 participants; low-certainty evidence). We found no evidence of an effect of the intervention for the remainder of the secondary outcomes: vascular-related death (two studies, not pooled due to differences in population, RR 0.33, 95% CI 0.01 to 8.00, P = 0.50, and RR 0.33, 95% CI 0.01 to 7.72, P = 0.49; 142 participants; low-certainty evidence); recurrent events (RR 0.41, 95% CI 0.02 to 8.84, P = 0.57; 18 participants; very low-certainty evidence); incidence of other type of stroke (two studies, not pooled due to different type of index stroke, RR 6.11, 95% CI 0.33 to 111.71, P = 0.22, and RR 0.63, 95% CI 0.25 to 1.58, P = 0.32; 58 participants; very low-certainty evidence); and quality of life (physical component, MD -2.31, 95% CI -4.81 to 0.19, P = 0.07, and mental component, MD -2.16, 95% CI -5.91 to 1.59, P = 0.26; 1 study; 102 participants; low-certainty evidence). Adverse events were reported by two studies (57 participants; very low-certainty evidence), one trial reporting extracranial haemorrhage (RR 0.25, 95% CI 0.04 to 1.73, P = 0.16) and the other one reporting bleeding complications (RR 0.32, 95% CI 0.01 to 7.35, P = 0.47). Longer follow-up (more than three months) One small trial assessed functional outcome with both the Barthel Index for activities of daily living (MD 7.09, 95% CI -5.16 to 19.34, P = 0.26), and the Rivermead Mobility Index for mobility (MD 1.30, 95% CI -1.31 to 3.91, P = 0.33) (52 participants; very low-certainty evidence). We carried out meta-analysis for vascular-related death (RR 1.02, 95% CI 0.78 to 1.35, P = 0.86; 5 studies; 2237 participants; low-certainty evidence) and fatal recurrent events (RR 0.69, 95% CI 0.31 to 1.55, P = 0.37; 3 studies; 1819 participants; low-certainty evidence). We found no evidence of an effect of the intervention for mood (MD 1.00, 95% CI -2.07 to 4.07, P = 0.61; 1 study; 14 participants; low-certainty evidence). Incidence of other type of stroke and quality of life were not reported. Adverse events (all combined) were reported by only one study (RR 0.94, 95% CI 0.56 to 1.58, P = 0.82; 1455 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

We are very uncertain of the effect of marine-derived n-3 PUFAs therapy on functional outcomes and dependence after stroke as there is insufficient high-certainty evidence. More well-designed RCTs are needed, specifically in acute stroke, to determine the efficacy and safety of the intervention. Studies assessing functional outcome might consider starting the intervention as early as possible after the event, as well as using standardised, clinically relevant measures for functional outcomes, such as the modified Rankin Scale. Optimal doses remain to be determined; delivery forms (type of lipid carriers) and mode of administration (ingestion or injection) also need further consideration.

A Consistency Model for Identifying the Effects of n-3 and n-6 Fatty Acids on Lipoproteins in Dialysis Patients

Numerous randomized controlled trials (RCTs) and meta-analyses have assessed the effects of supplemental dietary polyunsaturated fatty acids (PUFAs) on levels of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) and the LDL/HDL ratio in patients receiving renal replacement therapy (RRT). However, results are ambiguous due to mixed reports of various nutrients used in the intervention group. We performed a network meta-analysis of RCTs to assess the effects of PUFAs on lipid profiles in patients undergoing RRT. RCTs performed before November 2021 were gathered from three databases. The means, standard deviations and the number of cases for each arm were independently extracted by two authors to form a network meta-analysis of LDL and HDL levels and the LDL/HDL ratio in a random effects model. Twenty-eight RCTs (n = 2017 subjects) were included in this study. The pooled results revealed that the combination of omega-3 fatty acids (n-3) and omega-6 fatty acids (n-6) produced significantly lower LDL (standardized mean difference (SMD) = −1.43, 95% confidence interval: −2.28 to −0.57) than the placebo. Both n-3 fatty acids (SMD = 0.78) and the combination of n-3 + n-6 (SMD = 1.09) benefited HDL significantly compared with placebo. Moreover, n-3 alone also exhibited a significantly lower LDL/HDL ratio than placebo. Collectively, PUFAs seem to be adequate nutrients for controlling lipoproteins in patients undergoing RRT. Specifically, n-3 + n-6 supplementation improved LDL levels, while n-3 improved HDL levels and the LDL/HDL ratio. However, our data provide limited information on specific dosages of PUFAs to form a concrete recommendation.

Association of Dietary Intakes and Genetically Determined Serum Concentrations of Mono and Poly Unsaturated Fatty Acids on Chronic Kidney Disease: Insights from Dietary Analysis and Mendelian Randomization

Polyunsaturated fatty acid (PUFA) intake is generally associated with better renal function, while the association of monounsaturated fatty acids (MUFAs) remains unconfirmed. Mendelian randomization (MR) analysis was used to obtain unconfounded estimates of the causal association of dietary intake and genetically determined serum PUFA and MUFA levels with measures of renal function. Data from participants of the National Health and Nutrition Examination Surveys (NHANES) from 2005 to 2010 were used. Data from the largest genome-wide association studies (GWAS) on MUFAs, PUFAs, eGFR, and chronic kidney disease (CKD) were analysed for the entire sample. A total of 16,025 participants were included. eGFR improved across increasing quartiles of total PUFA intake from 86.3 ± 0.5 (Q1) to 96.2 ± 0.5 mL/min/1.73 m² (Q4), (p < 0.001). Conversely, there was no association between MUFA intake and measures of renal function (all p > 0.21). In multivariable models, the top quartile of PUFA intake had a 21% lower risk for CKD, but there was no significant association between CKD risk and MUFA intake. Genetically determined serum MUFA (heptadecenoate (17:1), myristoleic acid (14:1), and palmitoleic acid (16:1)) and PUFA (α-linolenic acid and eicosapentaenoic acid) concentrations had no significant association with eGFR and CKD risk. Additionally, no association was found in the analyses stratified by diabetes status. Higher dietary PUFA intake is associated with lower risk of CKD, while there was no association with serum levels of MUFAs or PUFAs. Additional studies including clinical trials are warranted.

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.

Dietary Lipids and Dyslipidemia in Chronic Kidney Disease

The progression of chronic kidney disease (CKD) leads to altered lipid metabolism. CKD patients exhibit high blood triglyceride (TG) levels, reduced concentrations and functionality of high-density lipoproteins (HDL), and elevated levels of atherogenic small, dense, low-density lipoproteins (sdLDL). Disorders of lipid metabolism and other metabolic disturbances place CKD patients at high risk for cardiovascular disease (CVD). Extensive evidence supports the cardioprotective effects of unsaturated fatty acids, including their beneficial effect on serum cholesterol and TG levels. Dietary lipids might therefore be especially important in the nutritional management of CKD. We review current dietary recommendations for fat intake by CKD patients and suggest potential nutritional interventions by emphasizing dietary lipids that might improve the blood lipid profile and reduce cardiovascular risk in CKD.

Lipoproteins in chronic kidney disease: from bench to bedside

Chronic kidney disease (CKD) is associated with high cardiovascular risk. CKD patients exhibit a specific lipoprotein pattern termed 'uraemic dyslipidaemia', which is characterized by rather normal low-density lipoprotein cholesterol, low high-density lipoprotein cholesterol, and high triglyceride plasma levels. All three lipoprotein classes are involved in the pathogenesis of CKD-associated cardiovascular diseases (CVDs). Uraemia leads to several modifications of the structure of lipoproteins such as changes of the proteome and the lipidome, post-translational protein modifications (e.g. carbamylation) and accumulation of small-molecular substances within the lipoprotein moieties, which affect their functionality. Lipoproteins from CKD patients interfere with lipid transport and promote inflammation, oxidative stress, endothelial dysfunction as well as other features of atherogenesis, thus contributing to the development of CKD-associated CVD. While, lipid-modifying therapies play an important role in the management of CKD patients, their efficacy is modulated by kidney function. Novel therapeutic agents to prevent the adverse remodelling of lipoproteins in CKD and to improve their functional properties are highly desirable and partially under development.

Plasma Fatty Acids and Quantitative Ultrasound, DXA and pQCT Derived Parameters in Postmenopausal Spanish Women

Different factors may contribute to the development of osteopenia or osteoporosis. Fatty acids are key nutrients for health, and a number of studies have reported an association between bone mineral density (BMD) and fatty acid intake. We aimed to investigate the relationships between serum levels of different fatty acids and bone parameters determined by quantitative bone ultrasound (QUS), peripheral quantitative computed tomography (pQCT), and dual-energy X-ray absorptiometry (DXA) in a sample of Spanish postmenopausal women. We enrolled a total of 301 postmenopausal women (median age 59 years; interquartile range (IQR) 7) in this study. All participants underwent full densitometric screening, including calcaneal quantitative ultrasound (QUS), peripheral quantitative computed tomography (pQCT), and dual-energy X-ray absorptiometry (DXA), as well as plasma fatty acid measurement. After adjustment for potential confounders, plasma n-3 polyunsaturated fatty acid (PUFA) levels correlated with BMD in the spine (r = 0.150; p = 0.014) and femoral neck (r = 0.143; p = 0.019). By multiple linear regression, an independent statistically significant positive relationship was observed between BMD in the spine and BMI (β = 0.288; p = 0.001) as well as total plasma n-3 PUFAs (β = 0.155; p = 0.009). The plasma n-3 PUFA level was also a significant and positive predictor of BMD at the femoral neck (β = 0.146; p = 0.009). Independent risk factors for low BMD (T-score ≤ 1) were determined by logistic regression analysis, and a relatively high level of plasma n-3 PUFAs (OR = 0.751; 95% CI 0.587-0.960, p = 0.022) was identified as a protective factor against low bone mass. In this single-center sample of Spanish postmenopausal women, we reported a significant positive and statistically independent association between BMD and plasma levels of n-3 PUFAs.

Are Nutraceuticals Beneficial in Chronic Kidney Disease?

Chronic kidney disease (CKD) is a worldwide health problem in which prevalence is constantly rising. The pathophysiology of CKD is complicated and has not been fully resolved. However, elevated oxidative stress is considered to play a vital role in the development of this disease. CKD is also thought to be an inflammatory disorder in which uremic toxins participate in the development of the inflammatory milieu. A healthy, balanced diet supports the maintenance of a good health status as it helps to reduce the risk of the development of chronic diseases, including chronic kidney disease, diabetes mellitus, and hypertension. Numerous studies have demonstrated that functional molecules and nutrients, including fatty acids and fiber as well as nutraceuticals such as curcumin, steviol glycosides, and resveratrol not only exert beneficial effects on pro-inflammatory and anti-inflammatory pathways but also on gut mucosa. Nutraceuticals have attracted great interest recently due to their potential favorable physiological effects on the human body and their safety. This review presents some nutraceuticals in which consumption could exert a beneficial impact on the development and progression of renal disease as well cardiovascular disease.

Oral supplementation with omega-3 fatty acids and inflammation markers in patients with chronic kidney disease in hemodialysis

Chronic kidney disease (CKD) is an increasingly common public health problem that increases the risk of death because of cardiovascular complications by 2-3 times compared with the general population. This research concerns a prospective, randomized, double-blind study in patients with CKD undergoing hemodialysis. The participants were assigned to 1 of 2 groups: the study group (group A; 46 patients) received 4 capsules (2.4 g) of omega-3 fatty acids daily during the 12-week intervention, while patients in the control group (group B; 47 patients) received 4 capsules of paraffin oil. The patients' general characteristics, nutritional indicators, renal disease markers and inflammatory markers (C-reactive protein, interleukin (IL)-6, IL-10, and tumour necrosis factor alpha (TNF-α)) were evaluated. No differences were found between the general characteristics of the patients (P < 0.05), and no differences were shown in the nutritional indicators and markers of kidney disease (P < 0.05). Patients in group A showed significant decreases in levels of C-reactive protein, IL-6, TNF-α, and the IL-10/IL-6 ratio after 12 weeks of supplementation (P < 0.05). Patients in group B did not show any significant changes in concentrations of inflammatory markers during the intervention (P < 0.05). In conclusion, oral supplementation with omega-3 fatty acids produces a significant decrease in the concentrations of inflammation markers in patients with chronic kidney disease on hemodialysis. Novelty Oral supplementation with omega-3 fatty acids produced significant decreases in the concentrations of inflammation markers. This supplementation could be given to patients with uremic syndrome and coronary heart disease to reduce cardiovascular risk.

Lipid management in patients with chronic kidney disease

An increased risk of cardiovascular disease, independent of conventional risk factors, is present even at minor levels of renal impairment and is highest in patients with end-stage renal disease (ESRD) requiring dialysis. Renal dysfunction changes the level, composition and quality of blood lipids in favour of a more atherogenic profile. Patients with advanced chronic kidney disease (CKD) or ESRD have a characteristic lipid pattern of hypertriglyceridaemia and low HDL cholesterol levels but normal LDL cholesterol levels. In the general population, a clear relationship exists between LDL cholesterol and major atherosclerotic events. However, in patients with ESRD, LDL cholesterol shows a negative association with these outcomes at below average LDL cholesterol levels and a flat or weakly positive association with mortality at higher LDL cholesterol levels. Overall, the available data suggest that lowering of LDL cholesterol is beneficial for prevention of major atherosclerotic events in patients with CKD and in kidney transplant recipients but is not beneficial in patients requiring dialysis. The 2013 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for Lipid Management in CKD provides simple recommendations for the management of dyslipidaemia in patients with CKD and ESRD. However, emerging data and novel lipid-lowering therapies warrant some reappraisal of these recommendations.

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.

Marine-derived n-3 fatty acids therapy for stroke

BACKGROUND

Currently, with stroke burden increasing, there is a need to explore therapeutic options that ameliorate the acute insult. There is substantial evidence of a neuroprotective effect of marine-derived n-3 polyunsaturated fatty acids (PUFAs) in experimental stroke, leading to a better functional outcome.

OBJECTIVES

To assess the effects of administration of marine-derived n-3 PUFAs on functional outcomes and dependence in people with stroke.Our secondary outcomes were vascular-related death, recurrent events, incidence of other type of stroke, adverse events, quality of life, and mood.

SEARCH METHODS

We searched the Cochrane Stroke Group trials register (6 August 2018), the Cochrane Central Register of Controlled Trials (CENTRAL; Issue 1, January 2019), MEDLINE Ovid (from 1948 to 6 August 2018), Embase Ovid (from 1980 to 6 August 2018), CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; from 1982 to 6 August 2018), Science Citation Index Expanded ‒ Web of Science (SCI-EXPANDED), Conference Proceedings Citation Index-Science - Web of Science (CPCI-S), and BIOSIS Citation Index. We also searched ongoing trial registers, reference lists, relevant systematic reviews, and used the Science Citation Index Reference Search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing marine-derived n-3 PUFAs to placebo or open control (no placebo) in people with a history of stroke or transient ischaemic attack (TIA), or both.

DATA COLLECTION AND ANALYSIS

At least two review authors independently selected trials for inclusion, extracted data, assessed risk of bias, and used the GRADE approach to assess the quality of the body of evidence. We contacted study authors for clarification and additional information on stroke/TIA participants. We conducted random-effects meta-analysis or narrative synthesis, as appropriate. The primary outcome was efficacy (functional outcome) assessed using a validated scale e.g. Glasgow Outcome Scale Extended (GOSE) dichotomised into poor or good clinical outcome, Barthel Index (higher score is better; scale from 0 to 100) or Rivermead Mobility Index (higher score is better; scale from 0 to 15).

MAIN RESULTS

We included 29 RCTs; nine of them provided outcome data (3339 participants). Only one study included participants in the acute phase of stroke (haemorrhagic). Doses of marine-derived n-3 PUFAs ranged from 400 mg/day to 3300 mg/day. Risk of bias was generally low or unclear in most trials, with a higher risk of bias in smaller studies. We assessed results separately for short (up to three months) and longer (more than three months) follow-up studies.Short follow-up (up to three months)Functional outcome was reported in only one pilot study as poor clinical outcome assessed with GOSE (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.36 to 1.68; 40 participants; very low quality evidence). Mood (assessed with GHQ-30, lower score better), was reported by only one study and favoured control (mean difference (MD) 1.41, 95% CI 0.07 to 2.75; 102 participants; low-quality evidence).We found no evidence of an effect of the intervention for the remainder of the secondary outcomes: vascular-related death (two studies, not pooled due to differences in population, RR 0.33, 95% CI 0.01 to 8.00, and RR 0.33, 95% CI 0.01 to 7.72; 142 participants; low-quality evidence); recurrent events (RR 0.41, 95% CI 0.02 to 8.84; 18 participants; very low quality evidence); incidence of other type of stroke (two studies, not pooled due to different type of index stroke, RR 6.11, 95% CI 0.33 to 111.71, and RR 0.63, 95% CI 0.25 to 1.58; 58 participants; very low quality evidence); and quality of life (physical component mean difference (MD) -2.31, 95% CI -4.81 to 0.19, and mental component MD -2.16, 95% CI -5.91 to 1.59; one study; 102 participants; low-quality evidence).Adverse events were reported by two studies (57 participants; very low quality evidence), one trial reporting extracranial haemorrhage (RR 0.25, 95% CI 0.04 to 1.73) and the other one reporting bleeding complications (RR 0.32, 95% CI 0.01 to 7.35).Longer follow-up (more than three months)One small trial assessed functional outcome with both Barthel Index (MD 7.09, 95% CI -5.16 to 19.34) for activities of daily living, and Rivermead Mobility Index (MD 1.30, 95% CI -1.31 to 3.91) for mobility (52 participants; very low quality evidence). We carried out meta-analysis for vascular-related death (RR 1.02, 95% CI 0.78 to 1.35; five studies; 2237 participants; low-quality evidence) and fatal recurrent events (RR 0.69, 95% CI 0.31 to 1.55; three studies; 1819 participants; low-quality evidence).We found no evidence of an effect of the intervention for mood (MD 1.00, 95% CI -2.07 to 4.07; one study; 14 participants; low-quality evidence). Incidence of other type of stroke and quality of life were not reported.Adverse events (all combined) were reported by only one study (RR 0.94, 95% CI 0.56 to 1.58; 1455 participants; low-quality evidence).

AUTHORS' CONCLUSIONS

We are very uncertain of the effect of marine-derived n-3 PUFAs therapy on functional outcomes and dependence after stroke as there is insufficient high-quality evidence. More well-designed RCTs are needed, specifically in acute stroke, to determine the efficacy and safety of the intervention.Studies assessing functionality might consider starting the intervention as early as possible after the event, as well as using standardised clinically-relevant measures for functional outcomes, such as the modified Rankin Scale. Optimal doses remain to be determined; delivery forms (type of lipid carriers) and mode of administration (ingestion or injection) also need further consideration.

The effects of fish oil on gene expression in patients with polycystic ovary syndrome

BACKGROUND

This study was conducted to determine the effects of fish oil administration on gene expression related to insulin, lipid and inflammation in women with polycystic ovary syndrome (PCOS).

MATERIALS AND METHODS

This randomized, double-blind, placebo-controlled trial was conducted among 40 subjects with PCOS, aged 18-40 years. Subjects were randomly allocated into two groups to take either 1000 mg omega-3 fatty acids from fish oil (n = 20) or placebo (n = 20) twice a day for 12 weeks. Gene expression related to insulin, lipid and inflammation was quantified in peripheral blood mononuclear cells (PBMC) of PCOS women with RT-PCR method.

RESULTS

Our study demonstrated that after the 12-week intervention, compared with the placebo, fish oil supplementation upregulated gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) (P < .001) in PBMC of subjects with PCOS. In addition, compared to the placebo, taking fish oil supplements downregulated gene expression of interleukin-1 (IL-1) (P = .02) and interleukin-8 (IL-8) (P = .01) in PBMC of subjects with PCOS. We did not observe any significant effect of fish oil supplementation on gene expression of lipoprotein(a) [LP(a)], low-density lipoprotein receptor (LDLR), glucose transporter 1 (GLUT-1), tumour necrosis factor alpha (TNF-α) and transforming growth factor beta (TGF-β) in PBMC of subjects with PCOS.

CONCLUSIONS

Overall, fish oil supplementation for 12 weeks to subjects with PCOS significantly improved gene expression of PPAR-γ, IL-1 and IL-8, but did not influence gene expression of LP(a), LDLR, GLUT-1, TNF-α and TGF-β.

Flaxseed Oil Supplementation Improve Gene Expression Levels of PPAR-γ, LP(a), IL-1 and TNF-α in Type 2 Diabetic Patients with Coronary Heart Disease

This study was carried out to determine the effects of flaxseed oil administration on gene expression levels related to insulin, lipid and inflammation in overweight diabetic patients with coronary heart disease (CHD). This randomized double-blind, placebo-controlled trial was conducted among 60 diabetic patients with CHD. Subjects were randomly allocated into two groups to intake either 1000 mg n-3 fatty acid from flaxseed oil containing 400 mg α-Linolenic acid [ALA (18:3n-3)] (n = 30) or placebo (n = 30) twice a day for 12 weeks. Gene expression related to insulin, lipid and inflammation were quantified in peripheral blood mononuclear cells (PBMC) of diabetic patients with CHD with RT-PCR method. Results of RT-PCR demonstrated that after the 12-week intervention, compared with the placebo, flaxseed oil supplementation could up-regulate gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) (P = 0.02) in PBMC of diabetic patients with CHD. In addition, compared with the placebo, taking flaxseed oil supplements down-regulated gene expression levels of lipoprotein(a) [LP(a)] (P = 0.001), interleukin-1 (IL-1) (P = 0.001) and tumor necrosis factor alpha (TNF-α) (P = 0.02) in PBMC of diabetic patients with CHD. We did not observe any significant effect of flaxseed oil supplementation on gene expression levels of low-density lipoprotein receptor (LDLR), IL-8 and transforming growth factor beta (TGF-β) in PBMC of diabetic patients with CHD. Overall, flaxseed oil supplementation for 12 weeks in diabetic patients with CHD significantly improved gene expression levels of PPAR-γ, LP(a), IL-1 and TNF-α, but did not influence LDLR, IL-8 and TGF-β.

Stirring the Pot: Can Dietary Modification Alleviate the Burden of CKD?

Diet is one of the largest modifiable risk factors for chronic kidney disease (CKD)-related death and disability. CKD is largely a progressive disease; however, it is increasingly appreciated that hallmarks of chronic kidney disease such as albuminuria can regress over time. The factors driving albuminuria resolution remain elusive. Since albuminuria is a strong risk factor for GFR loss, modifiable lifestyle factors that lead to an improvement in albuminuria would likely reduce the burden of CKD in high-risk individuals, such as patients with diabetes. Dietary therapy such as protein and sodium restriction has historically been used in the management of CKD. Evidence is emerging to indicate that other nutrients may influence kidney health, either through metabolic or haemodynamic pathways or via the modification of gut homeostasis. This review focuses on the role of diet in the pathogenesis and progression of CKD and discusses the latest findings related to the mechanisms of diet-induced kidney disease. It is possible that optimizing diet quality or restricting dietary intake could be harnessed as an adjunct therapy for CKD prevention or progression in susceptible individuals, thereby reducing the burden of CKD.

Effect of omega-3 fatty acid supplementation on serum lipids and vascular inflammation in patients with end-stage renal disease: a meta-analysis

Omega-3 fatty acids (O3FAs) are associated with lower cardiovascular disease (CVD) risk in adults. However, this association in patients with end-stage renal disease (ESRD) remains controversial prompting the need for investigation into the role of O3FAs on serum lipids and vascular inflammation markers. The present meta-analysis summarized the effects of O3FA supplementation on serum lipids and vascular inflammatory markers in patients with ESRD. PubMed, EmBase, and the Cochrane Library were searched to identify randomized controlled trials (RCTs) focused on serum lipids and vascular inflammation markers in patients with ESRD. Standard mean differences (SMD) were used to measure the effect of O3FA supplementation on serum lipids and vascular inflammatory markers. The final pooled analysis included 20 RCTs involving 1,461 patients with ESRD. The results indicated that O3FA supplementation reduced TG by 0.61, LDL by 0.35 and CRP by 0.56. However, O3FA had no significant effect on TC, HDL, albumin, hemoglobin, homocysteine, DBP, glucose, lipoprotein(a), and ferritin. O3FA supplementation is associated with lower several serum lipids and vascular inflammation markers in patients with ESRD.

Long chain n-3 polyunsaturated fatty acids and vascular function in patients with chronic kidney disease and healthy subjects: a cross-sectional and comparative study

Background

Patients with chronic kidney disease have a markedly increased cardiovascular mortality compared with the general population. Long chain n-3 polyunsaturated fatty acids have been suggested to possess cardioprotective properties. This cross-sectional and comparative study evaluated correlations between hemodynamic measurements, resistance artery function and fish consumption to the content of long chain n-3 polyunsaturated fatty acids in adipose tissue, a long-term marker of seafood intake.

Methods

Seventeen patients with chronic kidney disease stage 5 + 5d and 27 healthy kidney donors were evaluated with hemodynamic measurements before surgery; from these subjects, 11 patients and 11 healthy subjects had vasodilator properties of subcutaneous resistance arteries examined. The measurements were correlated to adipose tissue n-3 polyunsaturated fatty acids. Information on fish intake was obtained from a dietary questionnaire and compared with adipose tissue n-3 polyunsaturated fatty acids.

Results

Fish intake and the content of n-3 polyunsaturated fatty acids in adipose tissue did not differ between patients and controls. n-3 polyunsaturated fatty acid levels in adipose tissue were positively correlated to systemic vascular resistance index; (r = 0.44; p = 0.07 and r = 0.62; p < 0.05, chronic kidney disease and healthy subjects respectively) and negatively correlated to cardiac output index (r = −0.69; p < 0.01 and r = −0.50; p < 0.05, chronic kidney disease and healthy subjects respectively). No correlation was observed between n-3 polyunsaturated fatty acid levels in adipose tissue and vasodilator properties in resistance arteries. n-3 PUFA content in adipose tissue increased with increasing self-reported fish intake.

Conclusions

The correlations found, suggest a role for n-3 polyunsaturated fatty acids in hemodynamic properties. However, this is apparently not due to changes in intrinsic properties of the resistance arteries as no correlation was found to n-3 polyunsaturated fatty acids.

Interventions for lowering plasma homocysteine levels in dialysis patients

BACKGROUND

People with end-stage kidney disease (ESKD) have high rates of cardiovascular events. Randomised controlled trials (RCTs) of homocysteine-lowering therapies have not shown reductions in cardiovascular event rates in the general population. However, people with kidney disease have higher levels of homocysteine and may have different mechanisms of cardiovascular disease. We performed a systematic review of the effect of homocysteine-lowering therapies in people with ESKD.

OBJECTIVES

To evaluate the benefits and harms of established homocysteine lowering therapy (folic acid, vitamin B6, vitamin B12) on all-cause mortality and cardiovascular event rates in patients with ESKD.

SEARCH METHODS

We searched Cochrane Kidney and Transplant's Specialised Register to 25 January 2016 through contact with the Information Specialist using search terms relevant to this review.

SELECTION CRITERIA

Studies conducted in people with ESKD that reported at least 100 patient-years of follow-up and assessed the effect of therapies that are known to have homocysteine-lowering properties were included.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data using a standardised form. The primary outcome was cardiovascular mortality. Secondary outcomes included all-cause mortality, incident cardiovascular disease (fatal and nonfatal myocardial infarction and coronary revascularisation), cerebrovascular disease (stroke and cerebrovascular revascularisation), peripheral vascular disease (lower limb amputation), venous thromboembolic disease (deep vein thrombosis and pulmonary embolism), thrombosis of dialysis access, and adverse events. The effects of homocysteine-lowering therapies on outcomes were assessed with meta-analyses using random-effects models. Prespecified subgroup and sensitivity analyses were conducted.

MAIN RESULTS

We included six studies that reported data on 2452 participants with ESKD. Interventions investigated were folic acid with or without other vitamins (vitamin B6, vitamin B12). Participants' mean age was 48 to 65 years, and proportions of male participants ranged from 50% to 98%.Homocysteine-lowering therapy probably leads to little or no effect on cardiovascular mortality (4 studies, 1186 participants: RR 0.93, 95% CI 0.70 to 1.22). There was no evidence of heterogeneity among the included studies (I² = 0%). Homocysteine-lowering therapy had little or no effect on all-cause mortality or any other of this review's secondary outcomes. All prespecified subgroup and sensitivity analyses demonstrated little or no difference. Reported adverse events were mild and there was no increase in the incidence of adverse events from homocysteine-lowering therapies (3 studies, 1248 participants: RR 1.12, 95% CI 0.51 to 2.47; I(2) = 0%). Overall, studies were assessed as being at low risk of bias and there was no evidence of publication bias.

AUTHORS' CONCLUSIONS

Homocysteine-lowering therapies were not found to reduce mortality (cardiovascular and all-cause) or cardiovascular events among people with ESKD.

Ratio of dietary ω-3 and ω-6 fatty acids-independent determinants of muscle mass-in hemodialysis patients with diabetes

OBJECTIVE

ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) are essential nutrients in the human diet and possibly affect muscle mass. We evaluated the association between the dietary ratios of ω-3 and ω-6 PUFAs and muscle mass, indicated as skeletal muscle mass (SMM) and appendicular skeletal muscle mass (ASM), in patients with diabetes undergoing hemodialysis (HD).

METHODS

In this cross-sectional study, data on 69 patients with diabetes who underwent standard HD therapy were analyzed. For estimating muscle mass, anthropometric and bioelectrical impedance analyses were conducted following dialysis. In addition, routine laboratory and 3-d dietary data were obtained. The adequate intake (AI) cut-off for ω-3 PUFAs was 1.6 g/d and 1.1 g/d for male and female patients, respectively.

RESULTS

The average age of the participants was 63.0 ± 10.4 y. The mean ratios of ω-3/ω-6 PUFA intake, ω-6/ω-3 PUFA intake, SMM, and ASM of the patients were 0.13 ± 0.07, 9.4 ± 6.4, 24.6 ± 5.4 kg, and 18.3 ± 4.6 kg, respectively. Patients who had AI of ω-3 PUFAs had significantly higher SMM and ASM than did their counterparts. Linear and stepwise multivariable adjustment analyses revealed that insulin resistance and the ω-6/ω-3 PUFA ratio were the independent deleterious determinants of ASM normalized to height in HD patients.

CONCLUSIONS

Patients with AI of ω-3 PUFAs had total-body SMM and ASM that were more appropriate. A higher dietary ratio of ω-6/ω-3 PUFAs was associated with reduced muscle mass in HD patients.

Plasma n-3 Polyunsaturated Fatty Acids and Bone Mineral Density in Renal Transplant Recipients

OBJECTIVE

Renal transplant recipients (RTR) suffer high rates of bone loss and increased risk of fracture. Marine n-3 polyunsaturated fatty acids (n-3 PUFA), found mainly in fish and seafood, may have beneficial effects on bone and are positively associated with bone mineral density (BMD) in healthy elderly. The aim of this study was to investigate if this association prevails despite the more complex causes of bone loss in RTR.

DESIGN, SUBJECTS, AND METHODS

A total of 701 RTR were included in a cross-sectional analysis. BMD of lumbar spine, proximal femur, and distal forearm were measured by dual energy x-ray absorptiometry scan, and blood samples were drawn in the fasting state for measurement of plasma fatty acid composition 10 weeks posttransplant. Multiple linear regression analysis was used to assess the association between plasma marine n-3 PUFA levels and BMD.

RESULTS

Mean age was 52.2 years, and two-thirds were men. Based on femoral neck T-scores, 26% of patients were osteoporotic and 52% osteopenic. Z-scores increased significantly across quartiles of marine n-3 PUFA levels, and marine n-3 PUFA was a positive predictor of BMD at total hip and lumbar spine after multivariate adjustment. No association was found between n-6 PUFA content and BMD.

CONCLUSIONS

Plasma marine n-3 PUFA levels were positively associated with BMD at the hip and lumbar spine 10 weeks posttransplant.

Does Omega-3 supplementation decrease carotid intima-media thickening in hemodialysis patients?

Objective:

A randomized, double-blind, placebo-controlled clinical trial was performed to assess the effect of omega-3 supplementation (3 g/day) on atherosclerosis progression by measuring carotid intima-media thickness (cIMT) in hemodialysis (HD) patients.

Methods:

A total of 54 HD patients were randomized into two groups: Intervention group (n = 27), in which patients were given 3 g/day omega-3 for 6 months and placebo group (n = 27), in which patients received placebo using the same administration protocol. All patients underwent a carotid artery ultrasound scan to measure cIMT at baseline and at 6 months.

Findings:

cIMT decreased significantly in omega-3 group (0.79 ± 0.21 mm at baseline vs. 0.65 ± 0.18 mm at 6 months, P < 0.001). On the other hand, a nonsignificant increase in cIMT was seen in placebo group (0.75 ± 0.17 mm at baseline vs. 0.79 ± 0.17 mm at 6 months, P = 0.12). Moreover, cIMT was statistically significantly different between omega-3 and placebo groups at 6 months (P < 0.001). After 6 months, a statistically significant increase was observed in high-density lipoprotein level in omega-3 group compared to placebo group (P = 0.03). Urea reduction ratio was also statistically significantly higher in omega-3 than placebo group at 6 months (P = 0.03). No significant difference was observed in terms of other variables between the two groups.

Conclusion:

These data suggested that omega-3 supplementation plays a protective role in the progression of atherosclerosis in HD patients.

Mitochondria: a new therapeutic target in chronic kidney disease

Cellular metabolic changes during chronic kidney disease (CKD) may induce higher production of oxygen radicals that play a significant role in the progression of renal damage and in the onset of important comorbidities. This condition seems to be in part related to dysfunctional mitochondria that cause an increased electron "leakage" from the respiratory chain during oxidative phosphorylation with a consequent generation of reactive oxygen species (ROS). ROS are highly active molecules that may oxidize proteins, lipids and nucleic acids with a consequent damage of cells and tissues. To mitigate this mitochondria-related functional impairment, a variety of agents (including endogenous and food derived antioxidants, natural plants extracts, mitochondria-targeted molecules) combined with conventional therapies could be employed. However, although the anti-oxidant properties of these substances are well known, their use in clinical practice has been only partially investigated. Additionally, for their correct utilization is extremely important to understand their effects, to identify the correct target of intervention and to minimize adverse effects. Therefore, in this manuscript, we reviewed the characteristics of the available mitochondria-targeted anti-oxidant compounds that could be employed routinely in our nephrology, internal medicine and renal transplant centers. Nevertheless, large clinical trials are needed to provide more definitive information about their use and to assess their overall efficacy or toxicity.

Ratio of Dietary n-6/n-3 Polyunsaturated Fatty Acids Independently Related to Muscle Mass Decline in Hemodialysis Patients

Background

n-3 polyunsaturated fatty acids (PUFAs) might be useful nutritional strategy for treating patients with sarcopenia. We evaluated the effect of the intake of dietary n-3 PUFAs on the skeletal muscle mass (SMM), appendicular skeletal muscle mass (ASM), and its determinants in patients receiving standard hemodialysis (HD) treatment for the management of end stage renal disease.

Methods

In this cross-sectional study, data of 111 HD patients were analyzed. Anthropometric and bioelectrical impedance measurements used to estimate the muscle mass were performed the day of dialysis immediately after the dialysis session. Routine laboratory and 3-day dietary data were also collected. The cutoff value of adequate intake (AI) for both n-3 PUFAs and alpha-linolenic acid (ALA) was 1.6 g/day and 1.1 g/day for men and women, respectively.

Results

The mean age, mean dietary n-3 PUFAs intake, ALA intake, ratio of n-6/n-3 PUFAs intake, SMM, and ASM of patients were 61.4 ± 10.4 years, 2.0 ± 1.3 g/day, 1.5 ± 1.0 g/day, 9.5 ± 6.7 g/day, 23.9 ± 5.5 kg, and 17.5 ± 4.5 kg, respectively. A higher SMM and ASM significantly observed in patients who achieved an AI of n-3 PUFAs. Similar trends appeared to be observed among those patients who achieved the AI of ALA, but the difference was not significantly, except for ASM (P = 0.047). No relevant differences in demographics, laboratory and nutritional parameters were observed, regardless of whether the patients achieved an AI of n-3 PUFAs. Multivariate analysis showed that the BMI and equilibrated Kt/V were independent determinants of the muscle mass. Moreover, the ratio of n-6/n-3 PUFAs was an independent risk determinant of reduced ASM in HD patients.

Conclusion

Patients with an AI of n-3 PUFAs had better total-body SMM and ASM. A higher dietary ratio of n-6/n-3 PUFAs seemed to be associated with a reduced muscle mass in HD patients.

Effect of Omega-3 fatty acids on blood pressure and serum lipids in continuous ambulatory peritoneal dialysis patients

OBJECTIVE

Hypertension and hyperlipidemia are two major risk factors for cardiovascular disease in continuous ambulatory peritoneal dialysis (CAPD) patients. This study was designed to investigate the effect of omega-3 fatty acids on blood pressure (BP) and serum lipids in CAPD patients.

METHODS

This study was a randomized double-blind clinical trial in which 90 CAPD patients were randomly assigned to either the omega-3 or the placebo group. Patients in omega-3 group received 3 g/day omega-3 for 8 weeks, whereas patients in the control group received placebo. At baseline and at the end of 8 weeks, the patients' BP was controlled, and serum biochemistry was measured.

FINDINGS

Mean systolic BP decreased (-22.2 ± 14.2 mmHg) in the omega-3 group at the end of the study while in the placebo group increased (+0.5 ± 30.2 mmHg) (P < 0.0001). Mean diastolic BP of the omega-3 group decreased more (-11.95 ± 11.9 mmHg) comparing with the placebo group (-1.1 ± 17.3 mmHg) (P = 0.001). There were no significant differences between the two groups in mean changes in serum triglyceride, and total, high-density lipoprotein, and low-density lipoprotein cholesterol.

CONCLUSION

The results of this study indicate that omega-3 reduced BP significantly but had no effect on lipid profile in our CAPD patients.

Associations of fish oil and vitamin B and E supplementation with cardiovascular outcomes and mortality in people receiving haemodialysis: a review

Background

Cardiovascular complications are the leading cause of mortality in patients with end-stage kidney disease. Research indicates that the Mediterranean diet is protective of cardiovascular disease in the general population. Components of this diet have been trialled in haemodialysis patients with the aim of reducing the risk of cardiovascular disease and improving associated risk factors. Components include fish, fruit and vegetables in the form of fish oil supplements and vitamin and antioxidant supplements. This narrative review provides an overview of observational studies, and interventional and randomised controlled trials examining the association of these supplements with cardiovascular outcomes in haemodialysis patients.

Methods

We reviewed the relevant literature by searching English-language publications in Web of Science and references from relevant articles published since 1992. Eight-seven abstracts were reviewed and 38 relevant articles were included.

Results

The extant literature suggests that risk of mortality is reduced in patients with a higher fish intake and those with higher serum omega-3 fatty acid levels. However, the pathways by which risk of mortality is reduced have not been fully extrapolated. While only a few studies have examined the effect of vitamin B supplementation in haemodialysis patients, these studies suggest that supplementation alone does not reduce the risk of mortality. Finally, studies examining vitamin E supplementation have drawn inconsistent conclusions regarding its pro-oxidant or antioxidant effects. Differences between studies are likely due to methodological variations in regards to dose, route of administration and treatment duration.

Conclusions

Nutritional and dietary supplementation in haemodialysis patients is an area which requires larger, more methodologically robust randomised controlled trials to determine if risk of cardiovascular outcomes can be improved.

Effects of fish oil on serum lipid profile in dialysis patients: a systematic review and meta-analysis of randomized controlled trials

Background

The effects of fish oil supplements on lipid profile in dialysis patients are controversial. With increasing interest in the potential health benefits of fish oil, it is important to explore its real effects.

Objective

We aimed to identify and quantify the effects of fish oil on triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in dialysis patients.

Methods

PubMed, EMBASE and the Cochrane Central Register of Controlled Trials were searched for relevant trials of fish oil and lipid profile in dialysis patients. We identified 209 potential studies and included 13 randomized controlled trials. Eligible studies, determined by consensus using predefined criteria, were reviewed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and a meta-analysis was performed.

Results

Compared with the control group, serum TG and TC levels in the fish oil group were reduced by 0.23 mmol/L (95% CI, −0.31, −0.14, P <0.01) and 0.12 mmol/L (95% CI, −0.23, −0.01, P =0.03), respectively. HDL-C levels were increased by 0.20 mmol/L (95% CI, 0.01, 0.40, P <0.01) attributable to fish oil. In contrast, fish oil did not influence serum LDL-C levels. Subgroup analysis showed the effects of fish oil were stronger in subjects with higher baseline TG levels, and the long-term intervention (>12w) demonstrated a tendency towards greater improvement of serum HDL-C and LDL-C levels compared with short-term intervention (≤12 w). However, both of the changes were not statistically significant in meta-regression analysis. There were no obvious difference in effects of different doses and components of fish oil on lipid levels.

Conclusion

Fish oil supplements reduced serum TG and TC levels, and increased HDL-C levels, without affecting LDL-C levels among dialysis patients. It should benefit patients at risk of cardiovascular diseases. Based on randomized controlled trials, we suggested a daily supplement dose of fish oil for dialysis patients of >1 g, but a high dose might not be necessary.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-511X-13-127) contains supplementary material, which is available to authorized users.

Oxidation of marine omega-3 supplements and human health

Marine omega-3 rich oils are used by more than a third of American adults for a wide range of purported benefits including prevention of cardiovascular disease. These oils are highly prone to oxidation to lipid peroxides and other secondary oxidation products. Oxidized oils may have altered biological activity making them ineffective or harmful, though there is also evidence that some beneficial effects of marine oils could be mediated through lipid peroxides. To date, human clinical trials have not reported the oxidative status of the trial oil. This makes it impossible to understand the importance of oxidation to efficacy or harm. However, animal studies show that oxidized lipid products can cause harm. Oxidation of trial oils may be responsible for the conflicting omega-3 trial literature, including the prevention of cardiovascular disease. The oxidative state of an oil can be simply determined by the peroxide value and anisidine value assays. We recommend that all clinical trials investigating omega-3 harms or benefits report the results of these assays; this will enable better understanding of the benefits and harms of omega-3 and the clinical importance of oxidized supplements.

The effect of n-3 polyunsaturated fatty acids on plasma lipids and lipoproteins in patients with chronic renal failure--a meta-analysis of randomized controlled trials

OBJECTIVE

To systemically review and analyze the effect of n-3 polyunsaturated fatty acid (PUFA) consumption on plasma lipids and lipoproteins in patients with end-stage renal disease.

DESIGN

Systemic review, with meta-analysis of randomized controlled clinical trials.

METHODS

We performed a systemic review and meta-analysis of the lipid-modulating effects of n-3 PUFAs by combining evidences from 10 randomized controlled trials including 557 patients with end-stage renal disease.

RESULTS

Pooled analysis revealed that n-3 PUFA intake significantly reduced serum triglyceride levels by -0.78 mmol/L (95% confidence interval: -1.12 to -0.44 mmol/L, P < .0001). Consumption of n-3 PUFAs also reduced the plasma low-density lipoprotein cholesterol levels by -0.09 mmol/L and elevated plasma high-density lipoprotein cholesterol levels by -0.25 mmol/L, but these changes were not statistically significant. Plasma levels of total cholesterols were elevated in both n-3 PUFA and control groups, with a lesser increase in the n-3 PUFA group, without statistical significance. Metaregression showed no correlation between the amounts or duration of n-3 PUFA intake and their lipid-modulating effects.

CONCLUSIONS

In our meta-analysis, n-3 PUFA consumption significantly lowered the serum triglyceride levels. No significant changes were found on the degrees of low-density lipoprotein cholesterol reduction and total cholesterol or high-density lipoprotein cholesterol elevation effects.

Dietary and synthetic activators of the antistress gene response in treatment of renal disease

Renal failure is associated with increased vascular inflammation, oxidative stress and dicarbonyl stress linked to development of cardiovascular disease, and other complications. The endogenous defense to inflammatory, oxidative, and dicarbonyl challenge to vascular function is coordinated by nuclear factor E2-related factor 2 (nrf2), kelch-related erythroid cell-derived protein with CNC homology (ECH) protein 1 (keap1), and antioxidant response element-linked gene expression in the antistress gene response. Intervention trials of the synthetic nrf2 activator, bardoloxone methyl, in patients with advanced diabetic nephropathy, showing improvement of renal function and decreased inflammation, suggest that nrf2 activators may have therapeutic benefit in chronic renal failure. Activators of nrf2 are of both synthetic and dietary origin. The aim of this review is to describe the "nrf2/keap1/antioxidant response element" transcriptional system and studies of this system in renal failure, and to assess the current status and future prospects that dietary nrf2 activators may be of benefit to patients with chronic renal failure.

Protein oxidative stress and dyslipidemia in dialysis patients

Our aim was to investigate and determine the associations between oxidative stress (OS), dyslipidemia and inflammation in patients treated with continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD) using observational cross-sectional study. Twenty patients in CAPD and 48 in HD for at least 8 weeks and aged ≥18 years were included in the study. Individuals with malignant or acute inflammatory disease were excluded. A control group of 17 healthy individuals was also recruited. The biochemical parameter evaluations were analyzed using colorimetric kits for albumin, serum glucose, total cholesterol (TC) and lipid fractions. To determine the inflammatory status, CRP, IL-6 and TNF-α were analyzed by automated chemiluminescence kits. Plasma advanced oxidation protein products (AOPP) were determined by spectrophotometry. Mean AOPP levels were significantly higher for the HD group compared to the control, and there was no difference in AOPP concentrations between the control and CAPD groups. Dialysis patients had levels of inflammatory parameters higher than controls, and showed a high prevalence of patients with dyslipidemia, especially in CAPD. In the HD group, AOPP was positively correlated with triglycerides (TG) and inversely associated with HDL. Also the HD group was observed to have negative associations between TNF-α and HDL, LDL and TC. In the CAPD group, CRP was inversely correlated with HDL. Hemodialysis patients had increased protein OS and associations of inflammation and dyslipidemia were also observed in these dialysis groups. A more detailed characterization of the relations between oxidative stress and other more traditional risk factors has therapeutic importance, since cardiovascular diseases are the leading cause of death among dialysis patients.

Marine n-3 fatty acids, atrial fibrillation and QT interval in haemodialysis patients

Patients treated with haemodialysis are at high risk of sudden cardiac death (SCD) often caused by arrhythmias. Atrial fibrillation (AF) is frequent among haemodialysis patients and is associated with increased mortality. Prolonged QTc is a risk marker of ventricular arrhythmia and is thereby associated with SCD. Studies have suggested that n-3 PUFA may have an antiarrhythmic effect, but the exact mechanism is not clear. The aim of this study was to examine whether AF was associated with n-3 PUFA in plasma phospholipids and whether supplementation with n-3 PUFA would shorten the QTc interval in haemodialysis patients compared to placebo. In a double-blinded randomised, placebo-controlled intervention trial 206 haemodialysis patients with CVD were treated with 1·7 g n-3 PUFA or placebo (olive oil) daily for 3 months. Blood samples and electrocardiogram evaluations were carried out at baseline and after 3 months. The QT interval, PQ interval and heart rate were measured in all patients with sinus rhythm (SR). At baseline 13 % of patients had AF. The content of the n-3 PUFA, DHA, was significantly lower (P < 0·05) in serum of patients with AF compared with patients with SR. Thus, the DHA content was independently negatively associated with AF. Supplementation with n-3 PUFA did not shorten the QT interval significantly compared to the placebo group (P = 0·42), although subgroup analysis within the n-3 PUFA group revealed a shortening effects on QTc (P = 0·01). In conclusion, an inverse association was found between the presence of AF and the plasma DHA in haemodialysis patients. Intervention with n-3 PUFA did not shorten the QTc interval compared to placebo.

Dietary omega-3 fatty acid, ratio of omega-6 to omega-3 intake, inflammation, and survival in long-term hemodialysis patients

BACKGROUND

Mortality in long-term hemodialysis patients is high, mostly attributed to cardiovascular events, and may be related to chronic inflammation. We hypothesized that the anti-inflammatory benefits of higher dietary intake of omega-3 compared with omega-6 polyunsaturated fatty acids may modulate the inflammatory processes and decrease death risk.

STUDY DESIGN

Prospective cohort study using linear and Cox proportional regressions.

SETTING & PARTICIPANTS

145 hemodialysis patients from 8 DaVita dialysis clinics in Southern California in 2001-2007.

PREDICTORS

Intake of dietary omega-3 and ratio of omega-6 to omega-3 using 3-day food record supplemented by dietary interview.

OUTCOMES

1-year change in serum C-reactive protein (CRP) level and 6-year survival.

RESULTS

Patients were aged 53 ± 14 years (mean ± SD) and included 43% women and 42% African Americans. Median dietary omega-3 intake, ratio of omega-6 to omega-3 intake, baseline serum CRP level, and change in CRP level over 1 year were 1.1 (25th-75th percentile, 0.8-1.6) g/d, 9.3 (25th-75th percentile, 7.6-11.3), 3.1 (25th-75th percentile, 0.8-6.8) mg/L, and +0.2 (25th-75th percentile, -0.4 to +0.8) mg/L, respectively. In regression models adjusted for case-mix, dietary calorie and fat intake, body mass index, and history of hypertension, each 1-unit higher ratio of omega-6 to omega-3 intake was associated with a 0.55-mg/L increase in serum CRP level (P = 0.03). In the fully adjusted model, death HRs for the first (1.7-<7.6), second (7.6-<9.3), third (9.3-<11.3), and fourth (11.3-17.4) quartiles of dietary omega-6 to omega-3 ratio were 0.39 (95% CI, 0.14-1.18), 0.30 (95% CI, 0.09-0.99), 0.67 (95% CI, 0.25-1.79), and 1.00 (reference), respectively (P for trend = 0.06).

LIMITATIONS

3-day food record may underestimate actual dietary fat intake at an individual level.

CONCLUSIONS

Higher dietary omega-6 to omega-3 ratio appears to be associated with both worsening inflammation over time and a trend toward higher death risk in hemodialysis patients. Additional studies including interventional trials are needed to examine the association of dietary fatty acids with clinical outcomes in these patients.

Omega-3 fatty acids supplementation does not affect serum lipids in chronic hemodialysis patients

OBJECTIVE

The aim of this study was to test the hypothesis that omega-3 fatty acids have an effect on serum lipids and inflammation markers in chronic hemodialysis (HD) patients.

DESIGN

The study followed a single-blind, randomized, crossover design.

SETTING

The study was conducted at the Hemodialysis Unit of the Laikon General Hospital in Athens, Greece.

PATIENTS

A total of 25 chronic HD patients were included in the study (16 men, 9 women, age: 51 ± 15 years).

INTERVENTION

Patients were randomly assigned to one of the following 2 intervention groups: omega-3 fatty acids plus α-tocopherol (920 mg eicosapentaenoic Acid (EPA), 760 mg docosahexaenoic acid (DHA), 8 mg α-tocopherol in total per day) or α-tocopherol supplement (100 mg/week resulting in 14.2 mg/day) alone for 4 weeks. After a washout period of 4 weeks, the 2 groups were crossed.

MAIN OUTCOME MEASURES

Medical history data were collected and anthropometric and nutritional intake evaluation was performed at the beginning and at the end of both interventions. Hematological and biochemical parameters as well as C-reactive protein levels were measured.

RESULTS

No statistically significant results were recorded in the lipidemic profiles of the participants between baseline and the 2 interventions. C-reactive protein levels also did not change significantly between the 2 interventions (5.54 ± 3.33 to 6.70 ± 5.01 mg/L [P = .19] with vitamin E vs. 7.13 ± 5.04 to 6.87 ± 5.24 [P = .78] with omega-3, P overall = .53).

CONCLUSION

The results of this study do not provide support for the positive effects of omega-3 fatty acid supplementation in HD patients.