Fish-oil supplement has neutral effects on vascular and metabolic function but improves renal function in patients with Type 2 diabetes mellitus

Omega-3 fatty acids and endothelial function: A GRADE-assessed systematic review and meta-analysis

INTRODUCTION

N-3 polyunsaturated fatty acids (PUFAs) supplementation has been reported to have an impact on flow-mediated dilatation (FMD), a conventionally used clinical technique for estimating endothelial dysfunction. However, its proven effects on endothelial function are unclear. This systematic review and meta-analysis were conducted to evaluate the effects of n-3 PUFAs supplementation on FMD of the brachial artery.

METHOD

This study was performed following the PRISMA guidelines. To identify eligible RCTs, a systematic search was completed in PubMed/Medline, Scopus and Web of Science using relevant keywords. A fixed- or random-effects model was utilized to estimate the weighted mean difference (WMD) and 95% confidence interval (95% CI).

RESULTS

Thirty-two studies (with 35 arms) were included in this meta-analysis, involving 2385 subjects with intervention duration ranging from 4 to 48 weeks. The pooled meta-analysis demonstrated a significant effect of omega-3 on FMD (WMD = 0.8%, 95% CI = 0.3-1.3, p = .001) and heterogeneity was significant (I2  = 82.5%, p < .001).

CONCLUSION

We found that n-3 PUFA supplementation improves endothelial function as estimated by flow-mediated dilatation of the brachial artery.

Comparison of the efficacy of fish oil and probiotic supplementation on glucose and lipid metabolism in patients with type 2 diabetes: a systematic review and network meta-analysis

BACKGROUND

Abnormalities in glucose and lipid metabolism contribute to the progression and exacerbation of type 2 diabetes mellitus (T2DM). Fish oil and probiotics are dietary supplements that have the potential to improve glucose and lipid metabolism. However, their efficacy remains unclear in T2DM patients.

METHODS

PubMed, Embase, and the Cochrane Library were retrieved to collect randomized controlled trials (RCTs) on the efficacy of fish oil or probiotic supplementation in T2DM patients from the database inception to December 13, 2023. Primary outcome indicators encompassed glycated hemoglobin (HbA1c), homeostatic model assessment for insulin resistance (HOMA-IR) and blood lipid profile (triglyceride (TG) and total cholesterol (TC). Secondary outcome indicators included inflammatory markers such as tumor necrosis factor -α (TNF-α) and adipocytokine (including leptin and adiponectin). The R software was used for statistical analysis, and GraphPad Prism was used for figure rendering.

RESULTS

A total of 60 RCTs involving 3845 T2DM patients were included in the analysis. The results showed that the probiotics (Bifidobacterium, Lactobacillus, Lactococcus, Propionibacterium, etc.) were more effective in reducing HOMA-IR than fish oil (Surca = 0.935). Bifidobacterium demonstrated the highest efficacy in reducing HbA1c levels (Surca = 0.963). Regarding lipid metabolism, fish oil was superior to probiotics in lowering TG and TC levels (Surca values of 0.978 and 0.902, respectively). Furthermore, fish oil outperformed probiotics in reducing TNF-α (Surca = 0.839) and leptin (Surca = 0.712), and increasing adiponectin levels (Surca = 0.742). Node-splitting analysis showed good consistency (P > 0.05 for direct, indirect, and network comparison across various interventions).

CONCLUSIONS

In T2DM patients, fish oil was more effective than probiotics in regulating lipid metabolism. Probiotics outperformed fish oil in regulating glucose metabolism particularly; specifically, Bifidobacterium showed higher efficacy in reducing blood glucose.

Effects of Omega-3 Fatty Acids on Flow-mediated Dilatation and Carotid Intima Media Thickness: A Meta-analysis

PURPOSE OF REVIEW

To investigate the effects of omega-3 fatty acids on flow-mediated dilatation (FMD) and carotid intima-media thickness (CIMT) and explore the factors influencing these effects.

RECENT FINDINGS

FMD was significantly higher in the omega-3 fatty acid group compared to the control group (mean difference = 0.90%; p = 0.0003). In particular, the subgroup with CHD (both EPA + DHA < 1 g/day and ≥ 1 g/day) and the subgroup without CHD but with CHD risk factors (only EPA + DHA ≥ 1 g/day) showed significantly increased FMD after supplementation of omega-3 fatty acids. CIMT was not significantly different between the omega-3 fatty acid and control groups (standardized mean difference = -0.08; p = 0.26). Subgroup analysis of CHD patients was not conducted because of the limited number of studies. Intake of omega-3 fatty acids improved FMD in patients with CHD and patients with risk factors for CHD. Further research is needed on the effects of omega-3 fatty acids on CIMT.

Endothelial progenitor cells as an emerging cardiovascular risk factor in the field of food and nutrition research: advances and challenges

Dietary modifications can help prevent many cardiovascular disease (CVD) events. Endothelial progenitor cells (EPCs) actively contribute to cardiovascular system maintenance and could function as surrogate markers for evaluating improvement in cardiovascular health resulting from nutritional interventions. This review summarizes the latest research progress on the impact of food and nutrients on EPCs, drawing on evidence from human, animal, and in vitro studies. Additionally, current trends and challenges faced in the field are highlighted. Findings from studies examining cells as EPCs are generally consistent, demonstrating that a healthy diet, such as the Mediterranean diet or a supervised diet for overweight people, specific foods like olive oil, fruit, vegetables, red wine, tea, chia, and nutraceuticals, and certain nutrients such as polyphenols, unsaturated fats, inorganic nitrate, and vitamins, generally promote higher EPC numbers and enhanced EPC function. Conversely, an unhealthy diet, such as one high in sugar substitutes, salt, or fructose, impairs EPC function. Research on outgrowth EPCs has revealed that various pathways are involved in the modulation effects of food and nutrients. The potential of EPCs as a biomarker for assessing the effectiveness of nutritional interventions in preventing CVDs is immense, while further clarification on definition and characterization of EPCs is required.

Could a lipid oxidative biomarker be applied to improve risk stratification in the prevention of cardiovascular disease?

There is significant evidence demonstrating the influence of oxidative stress on atherosclerosis and cardiovascular diseases (CVD). However, oxidative biomarkers have not been applied to follow patients under primary or secondary prevention. Many factors can explain this paradox: the higher complexity of the methods applied to quantify oxidative markers, the high variability observed among the studies, the lack of reference values, and the weak correlation with clinical endpoints. This review presents the role of the major reactive oxygen species (ROS) involved in cardiovascular pathophysiology and how they can be neutralized by endogenous and exogenous antioxidants based on classical and recent studies, highlighting the importance of the secondary products of fatty acid oxidation as potential biomarkers. Furthermore, we discuss the great variability of oxidative stress biomarkers, using as an example data obtained from 55 studies. Among the molecules directly formed from lipid oxidation, such as malondialdehyde (MDA), oxidized LDL (oxLDL), and isoprostanes (F₂-IsoP), and those associated with general oxidative conditions (ferric-reducing antioxidant power (FRAP), superoxide dismutase (SOD), glutathione (GSH)), MDA was the most lipid biomarker evaluated in the treatments and proved to be an independent factor compared with traditional markers used in the algorithms to stratify the patient's risk. Finally, this review suggests four steps to follow, aiming to include MDA in the algorithms applied to estimate CVD risk.

The role of selected nutraceuticals in management of prediabetes and diabetes: An updated review of the literature

Dysglycemia is a disease state preceding the onset of diabetes and includes impaired fasting glycemia and impaired glucose tolerance. This review aimed to collect and analyze the literature reporting the results of clinical trials evaluating the effects of selected nutraceuticals on glycemia in humans. The results of the analyzed trials, generally, showed the positive effects of the nutraceuticals studied alone or in association with other supplements on fasting plasma glucose and post-prandial plasma glucose as primary outcomes, and their efficacy in improving insulin resistance as a secondary outcome. Some evidences, obtained from clinical trials, suggest a role for some nutraceuticals, and in particular Berberis, Banaba, Curcumin, and Guar gum, in the management of prediabetes and diabetes. However, contradictory results were found on the hypoglycemic effects of Morus, Ilex paraguariensis, Omega-3, Allium cepa, and Trigonella faenum graecum, whereby rigorous long-term clinical trials are needed to confirm these data. More studies are also needed for Eugenia jambolana, as well as for Ascophyllum nodosum and Fucus vesiculosus which glucose-lowering effects were observed when administered in combination, but not alone. Further trials are also needed for quercetin.

The Potential of the Mediterranean Diet to Improve Mitochondrial Function in Experimental Models of Obesity and Metabolic Syndrome

The abnormal expansion of body fat paves the way for several metabolic abnormalities including overweight, obesity, and diabetes, which ultimately cluster under the umbrella of metabolic syndrome (MetS). Patients with MetS are at an increased risk of cardiovascular disease, morbidity, and mortality. The coexistence of distinct metabolic abnormalities is associated with the release of pro-inflammatory adipocytokines, as components of low-to-medium grade systemic inflammation and increased oxidative stress. Adopting healthy lifestyles, by using appropriate dietary regimens, contributes to the prevention and treatment of MetS. Metabolic abnormalities can influence the function and energetic capacity of mitochondria, as observed in many obesity-related cardio-metabolic disorders. There are preclinical studies both in cellular and animal models, as well as clinical studies, dealing with distinct nutrients of the Mediterranean diet (MD) and dysfunctional mitochondria in obesity and MetS. The term “Mitochondria nutrients” has been adopted in recent years, and it depicts the adequate nutrients to keep proper mitochondrial function. Different experimental models show that components of the MD, including polyphenols, plant-derived compounds, and polyunsaturated fatty acids, can improve mitochondrial metabolism, biogenesis, and antioxidant capacity. Such effects are valuable to counteract the mitochondrial dysfunction associated with obesity-related abnormalities and can represent the beneficial feature of polyphenols-enriched olive oil, vegetables, nuts, fish, and plant-based foods, as the main components of the MD. Thus, developing mitochondria-targeting nutrients and natural agents for MetS treatment and/or prevention is a logical strategy to decrease the burden of disease and medications at a later stage. In this comprehensive review, we discuss the effects of the MD and its bioactive components on improving mitochondrial structure and activity.

Positive Effects of Extra-Virgin Olive Oil Supplementation and DietBra on Inflammation and Glycemic Profiles in Adults With Type 2 Diabetes and Class II/III Obesity: A Randomized Clinical Trial

Background

Evidence on the effects of dietary interventions on inflammatory markers in individuals with obesity and type 2 diabetes mellitus (T2DM) is scarce. Our study evaluated the effects of extra-virgin olive oil alone and in combination with a traditional Brazilian diet on inflammatory markers and glycemic profiles in adults with both T2DM and class II/III obesity.

Methods

Adults aged 18-64 years with T2DM and class II/III obesity were randomized into two intervention groups: 1) extra-virgin olive oil only and 2) extra-virgin olive oil + a traditional Brazilian diet (OliveOil+DietBra). Data on sociodemographic characteristics, lifestyle, anthropometry, biochemical markers and inflammatory markers were collected. The primary outcomes were glycemic parameters and inflammatory markers. The body mass index (BMI) and weight were the secondary outcomes.

Results

Forty individuals with T2DM and class II/III obesity were enrolled, and 34 (85%) completed the intervention course. The intake of olive oil was 37.88 ± 12.50 mL/day in the olive oil group and 37.71 ± 12.23 mL/day in the OliveOil+DietBra group, with no significant difference between groups (p = 0.484). Compared to the olive oil only group, the OliveOil+DietBra group had significantly lower levels of fasting insulin (p = 0.047) at the end of the intervention, whereas the other glycemic parameters were not altered. In the OliveOil+DietBra group, serum levels of inflammatory cytokines, IL-1α (p = 0.006) and adiponectin (p = 0.049) were lower and those of TNFα were higher (p = 0.037). There was a significant reduction in BMI and weight compared to the baseline values in the OliveOil+DietBra group (p = 0.015).

Conclusions

The intervention with OliveOil+DietBra effectively decreased the levels of fasting insulin, IL-1α and adiponectin, suggesting its beneficial role in improving the inflammatory profiles and fasting insulin levels in adults with class II/III obesity and T2DM.

Clinical Trial Registration

ClinicalTrials.gov, identifier: NCT02463435.

Omega-3 Fatty Acids and Their Interaction with the Gut Microbiome in the Prevention and Amelioration of Type-2 Diabetes

Type-2 diabetes mellitus (T2DM) is often linked with hyperglycemia, disturbed lipid profiles, inflammation, and gut dysbiosis. Omega-3 fatty acid supplementation has a vital role in the management of T2DM. As a result, a better understanding of the potential role of omega-3 fatty acids in the development and progression of T2DM by influencing the intestinal microflora will help to improve the therapeutic intervention for T2DM and related complications. Focusing on the molecular mechanisms and signaling pathways induced by omega-3 fatty acids, this paper attempts to comprehensively review and discuss the putative associations between omega-3 fatty acids, gut dysbiosis, and the pathophysiology of T2DM and its related comorbidities. In addition, we contemplate the importance of gut microbiota in T2DM prevention and treatment and ponder the role of omega-3 fatty acids in T2DM by positively modulating gut microbiota, which may lead to discovery of novel targets and therapeutic strategies thereby paving way for further comprehensive, mechanistic, and clinical studies.

Could nutrient supplements provide additional glycemic control in diabetes management? A systematic review and meta-analysis of randomized controlled trials of as an add-on nutritional supplementation therapy

This systematic review and meta-analysis assessed the antidiabetic effect of pharmaconutrients as an add-on in type 2 diabetes mellitus patients by pooling data from currently available randomized controlled trials (RCTs). Data sources included the PubMed and EMBASE, Cochrane Central Register of Controlled Trials. RCTs reporting changes in glycosylated hemoglobin (HbA1c), fasting blood glucose (FBG), or homeostasis model assessment of insulin resistance (HOMA-IR) levels following add-on pharmaconutritional therapies for T2DM patients consuming antidiabetic drugs were targeted. Using random-effects meta-analyses, we identified pharmaconutrients with effects on glycemic outcomes. Heterogeneity among studies was presented using I² values. Among 9537 articles, 119 RCTs with nine pharmaconutrients (chromium; coenzyme Q10; omega-3 fatty acids; vitamins C, D, and E; alpha-lipoic acid; selenium; and zinc) were included. Chromium (HbA1c, FBG, and HOMA-IR), coenzyme Q10 (HbA1c and FBG), vitamin C (HbA1c and FBG), and vitamin E (HbA1c and HOMA-IR) significantly improved glycemic control. Baseline HbA1c level and study duration influenced the effects of chromium and vitamin E on HbA1c level. Sensitivity analyses did not modify the pooled effects of pharmaconutrients on glycemic control. Administration of chromium, coenzyme Q10, and vitamins C and E for T2DM significantly improved glycemic control. This study has been registered in PROSPERO (CRD42018115229).

Efficacy and Safety of Da-Chai-Hu-Tang in Lipid Profiles in High-Risk, Statin-Treated Patients with Residual HyperTG: A 12-Week, Randomized, Active-Control, Open Clinical Study

Da-Chai-Hu-Tang (DCHT) is a herbal extract that has been shown to reduce serum triglyceride (TG) levels in animal experiments as well as small clinical trials. This study aimed to evaluate the efficacy and safety of DCHT in high-risk, statin-treated patients with residual hypertriglyceridemia (hyperTG). This was a 12-week, randomized, active-controlled, open-label, single-center trial. Of these patients, 42 had high cardiovascular risks whose LDL cholesterol levels were controlled by statin treatment; however, with TG levels of 200 to 500 mg/dL they were randomly assigned 1:1 to the OMEGA3 or DCHT group. The primary endpoint was defined as the percentage change in TG at 12 weeks, and changes in other lipid profiles and endothelial cell function were included as secondary endpoints. Safety analyses were also conducted. In the OMEGA3 group, the average TG level decreased from 294.5 ± 72.0 to 210.0 ± 107.8 mg/dL (p = 0.004), and in the DCHT group, from 288.7 ± 59.1 to 227.5 ± 98.1 mg/dL (p = 0.001). The percentage change in TG was −27.6 ± 33.6 and −22.4 ± 24.1 (p = 0.58), respectively, and there was no significant difference between the two groups. There were no severe adverse events in either group. In high-risk, statin-treated patients with residual hyperTG, the administration of OMEGA3 or DCHT for 12 weeks resulted in a significant reduction in TG, and the effect of DCHT was not inferior to that of OMEGA3.

Impact of following a healthy dietary pattern with co-consuming wolfberry on number and function of blood outgrowth endothelial cells from middle-aged and older adults

Blood outgrowth endothelial cells (BOECs) have received growing attention in relation to cardiovascular disease (CVD). However, the effect of diet intervention, a primary strategy for CVD prevention, on BOECs is not reported. This study aims to investigate the effect of following a healthy dietary pattern (HDP) with or without wolfberry consumption, healthy food with potential cardiovascular benefits, on the number and function of BOECs in middle-aged and older adults. Twenty-four subjects consumed either an HDP only (n = 9) or an HDP supplemented with 15 g day^-1 wolfberries (n = 15) for 16 weeks. At pre- and post-intervention, vascular health biomarkers and composite CVD risk indicators were assessed. BOECs were derived from peripheral blood mononuclear cells and their angiogenic and migration activities were measured. Isolated BOECs have typical endothelial cobblestone morphology, express von Willebrand factor and KDR. Consuming an HDP improved the BOEC colony's growth rate, which was demonstrated by significant time effects in the colony's culture time between passages 1 and 2 (P = 0.038). Both interventions increased BOECs' tube formation capacity. Moreover, HDP intervention contributed to a time effect on BOEC migration activity (P = 0.040 for t_1/2gap). Correlation analysis revealed that BOEC colony number was positively associated with blood pressure, atherogenic index, vascular age, and Framingham risk score. In conclusion, adherence to an HDP improved BOECs' function in middle-aged and older populations, while additional wolfberry consumption did not provide an enhanced effect. Our results provide mechanistic dissection on the beneficial effects on BOECs of dietary pattern modification.

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 ω-3 Polyunsaturated Fatty Acids-Derived Bioactive Lipids on Metabolic Disorders

Arachidonic acid (ARA) is an important ω-6 polyunsaturated fatty acid (PUFA), and docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and n-3 docosapentaenoic acid (n-3 DPA) are three well-known ω-3 PUFAs. These fatty acids can be metabolized into a number of bioactive lipids. Eicosanoids derived from ARA have drawn great attention because of their important and complex biofunctions. Although EPA, DHA and n-3 DPA have also shown powerful biofunctions, we have fewer studies of metabolites derived from them than those from ARA. Recently, growing research has focused on the bioaction of ω-3 PUFA-derived metabolites, which indicates their great potential for treating metabolic disorders. Most of the functional studies of these bioactive lipids focused on their anti-inflammatory effects. However, several studies elucidated their direct effects on pancreatic β cells, hepatocytes, adipocytes, skeletal muscle cells, and endothelial cells. These researches revealed the importance of studying the functions of metabolites derived from ω-3 polyunsaturated fatty acids other than themselves. The current review summarizes research into the effects of ω-3 PUFA-derived oxylipins on metabolic disorders, including diabetes, non-alcoholic fatty liver disease, adipose tissue dysfunction, and atherosclerosis.

Lipid-modifying effects of krill oil vs fish oil: a network meta-analysis

CONTEXT

Krill oil is a good source of n-3 phospholipids and has greater bioavailability than fish oil, which contains n-3 triglycerides. However, it is unclear whether krill oil affects circulating lipid concentrations more beneficially than fish oil.

OBJECTIVE

A network meta-analysis was conducted to compare the lipid-modifying effects of krill oil and fish oil.

DATA SOURCES

PubMed and Embase databases were searched.

STUDY SELECTION

A total of 64 randomized controlled trials that determined the lipid-modifying effects of krill oil or fish oil were selected.

DATA EXTRACTION

The MetaXL program was used for meta-analysis. A subgroup analysis and a network meta-regression were conducted to investigate the dose-response effect of the n-3 fatty acid content of fish oil and krill oil.

RESULTS

Krill oil was associated with significantly lower triglyceride levels than control supplements (weighted mean difference [WMD] -23.26 [95%CI, -38.84 to -7.69]). However, the net differences in triglycerides (WMD -4.07 [95%CI, -15.22 to 7.08]), low-density lipoprotein cholesterol (WMD 3.01 [95%CI, -5.49 to 11.51]), high-density lipoprotein cholesterol (WMD 1.37 [95%CI, -3.73 to 6.48]), and total cholesterol (WMD 1.69 [95%CI, -6.62 to 10.01]) were not significantly different between the krill oil and fish oil groups. One gram of n-3 fatty acids contained in fish oil and krill oil lowered median triglycerides by 8.971 mg/dL (95% credible interval [CrI], 2.27 to 14.04) and 9.838 mg/dL (95%CrI, 0.72 to 19.40), respectively.

CONCLUSIONS

The lipid-modifying effects of krill oil and fish oil do not differ. The reduction in triglycerides depends on the dose of n-3 fatty acids consumed.

Effects of long-term vitamin D and n-3 fatty acid supplementation on inflammatory and cardiac biomarkers in patients with type 2 diabetes: secondary analyses from a randomised controlled trial

AIMS/HYPOTHESIS

Interventions that reduce inflammation may delay progression of microvascular and macrovascular complications in diabetes. We examined the effects of vitamin D₃ and/or n-3 fatty acid supplementation vs placebo on 5 year changes in serum inflammatory and cardiac biomarkers in adults with type 2 diabetes.

METHODS

This study reports pre-specified secondary outcomes of the Vitamin D and Omega-3 Trial to Prevent and Treat Diabetic Kidney Disease, in which 1312 US adults with type 2 diabetes and without known cardiovascular disease, malignancy, or end-stage kidney disease were randomised using computer-generated random numbers in blocks of eight to vitamin D₃ (2000 IU/day) vs placebo and n-3 fatty acids (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]; 1 g/day) vs placebo in a 2 × 2 factorial design. Participants, examiners, and researchers assessing outcomes were blinded to intervention assignment. We measured serum IL-6, high-sensitivity C-reactive protein (hsCRP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) at baseline and after 2 and 5 years.

RESULTS

A total of 333 participants were randomised to vitamin D₃ and placebo n-3 fatty acids, 289 to n-3 fatty acids and placebo vitamin D₃, 370 to vitamin D₃ and n-3 fatty acids, and 320 to 2 placebos; 989 (75%) and 934 (71%) participants returned blood samples at 2 and 5 years, respectively. Participants had a mean age of 67.6 years (46% women). Overall, baseline geometric means of IL-6, hsCRP and NT-proBNP were 1.2 pg/ml, 1.9 mg/l and 262 ng/l, respectively. After 5 years, mean IL-6 and hsCRP remained within 6% of their baseline values while mean NT-proBNP increased by 55% overall. Compared with placebo, participants assigned to vitamin D₃ had a 1.24-fold greater increase in NT-proBNP over 5 years (95% CI 1.09, 1.41; p = 0.003), while IL-6 and hsCRP did not have a significant difference in change. Comparing n-3 fatty acids with placebo, there was no significant difference in change in IL-6, hsCRP or NT-proBNP. No heterogeneity was observed in subgroup analyses accounting for baseline eGFR, urine albumin to creatinine ratio, initial biomarker concentration, 25-hydroxyvitamin D level or EPA+DHA index.

CONCLUSIONS/INTERPRETATION

Among adults with type 2 diabetes, supplementation with vitamin D₃ or n-3 fatty acids did not reduce IL-6, hsCRP or NT-proBNP over 5 years.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01684722 FUNDING: The study was funded by grant R01DK088762 from the National Institute of Diabetes and Digestive and Kidney Diseases. Graphical abstract.

Effect of omega-3 polyunsaturated fatty acids in modulation of vascular tone under physiological and pathological conditions

Omega-3 polyunsaturated fatty acids (n-3 PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are mainly found in marine fish oils and commercially available fish oil supplements. Several studies have documented that n-3 PUFAs can reduce the risk of cardiovascular diseases through anti-inflammatory, anti-thrombotic, and anti-atherosclerotic properties. Notably, regulation of vascular tone is one of the most important bases of cardiovascular health and especially for maintaining blood pressure within optimal physiological ranges. Recent clinical and animal studies indicate an association between n-3 PUFAs and vascular functions. In this regard, many clinical trials and basic experimental studies have been conducted so far to investigate the influence of n-3 PUFAs on vascular tone. In this review, we have summarized the results obtained from both clinical and basic studies that evaluated the effect of n-3 PUFAs under physiological and pathological conditions. Moreover, we also focus on verifying the underlying basic molecular mechanism of n-3 PUFAs on the vascular system.

Analysis of the intricate effects of polyunsaturated fatty acids and polyphenols on inflammatory pathways in health and disease

Prevention and treatment of non-communicable diseases (NCDs), including cardiovascular disease, diabetes, obesity, cancer, Alzheimer's and Parkinson's disease, arthritis, non-alcoholic fatty liver disease and various infectious diseases; lately most notably COVID-19 have been in the front line of research worldwide. Although targeting different organs, these pathologies have common biochemical impairments - redox disparity and, prominently, dysregulation of the inflammatory pathways. Research data have shown that diet components like polyphenols, poly-unsaturated fatty acids (PUFAs), fibres as well as lifestyle (fasting, physical exercise) are important factors influencing signalling pathways with a significant potential to improve metabolic homeostasis and immune cells' functions. In the present manuscript we have reviewed scientific data from recent publications regarding the beneficial cellular and molecular effects induced by dietary plant products, mainly polyphenolic compounds and PUFAs, and summarize the clinical outcomes expected from these types of interventions, in a search for effective long-term approaches to improve the immune system response.

Omega-3 polyunsaturated fatty acid supplementation versus placebo on vascular health, glycaemic control, and metabolic parameters in people with type 1 diabetes: a randomised controlled preliminary trial

Background

The role of omega-3 polyunsaturated fatty acids (n-3PUFA), and the potential impact of n-3PUFA supplementation, in the treatment and management of type 1 diabetes (T1D) remains unclear and controversial. Therefore, this study aimed to examine the efficacy of daily high-dose-bolus n-3PUFA supplementation on vascular health, glycaemic control, and metabolic parameters in subjects with T1D.

Methods

Twenty-seven adults with T1D were recruited to a 6-month randomised, double-blind, placebo-controlled trial. Subjects received either 3.3 g/day of encapsulated n-3PUFA or encapsulated 3.0 g/day corn oil placebo (PLA) for 6-months, with follow-up at 9-months after 3-month washout. Erythrocyte fatty acid composition was determined via gas chromatography. Endpoints included inflammation-associated endothelial biomarkers (vascular cell adhesion molecule-1 [VCAM-1], intercellular adhesion molecule-1 [ICAM-1], E-selectin, P-selectin, pentraxin-3, vascular endothelial growth factor [VEGF]), and their mediator tumor necrosis factor alpha [TNFα] analysed via immunoassay, vascular structure (carotid intima-media thickness [CIMT]) and function (brachial artery flow mediated dilation [FMD]) determined via ultrasound technique, blood pressure, glycosylated haemoglobin (HbA1c), fasting plasma glucose (FPG), and postprandial metabolism.

Results

Twenty subjects completed the trial in full. In the n-3PUFA group, the mean ± SD baseline n-3PUFA index of 4.93 ± 0.94% increased to 7.67 ± 1.86% (P < 0.001) after 3-months, and 8.29 ± 1.45% (P < 0.001) after 6-months. Total exposure to n-3PUFA over the 6-months (area under the curve) was 14.27 ± 3.05% per month under n-3PUFA, and 9.11 ± 2.74% per month under PLA (P < 0.001). VCAM-1, ICAM-1, E-selectin, P-selectin, pentraxin-3, VEGF, TNFα, CIMT, FMD, blood pressure, HbA1c, FPG, and postprandial metabolism did not differ between or within groups after treatment (P > 0.05).

Conclusions

This study indicates that daily high-dose-bolus of n-3PUFA supplementation for 6-months does not improve vascular health, glucose homeostasis, or metabolic parameters in subjects with T1D. The findings from this preliminary RCT do not support the use of therapeutic n-3PUFA supplementation in the treatment and management of T1D and its associated complications.

Trial Registration ISRCTN, ISRCTN40811115. Registered 27 June 2017, http://www.isrctn.com/ISRCTN40811115.

Effects of fish oil supplementation on glucose control and lipid levels among patients with type 2 diabetes mellitus: a Meta-analysis of randomized controlled trials

BACKGROUND

Previous studies have yielded inconsistent findings on the role of fish oil in type 2 diabetes mellitus (T2DM). We systematically summarized the available evidence from randomized controlled trials (RCT) and aimed to investigate the effects of fish oil supplementation on glucose control and lipid levels among patients with T2DM.

METHODS

A comprehensive literature search was performed in electronic databases (PubMed, ProQuest, Cochrane Library, CNKI, VIP, and Wanfang) to identify all relevant RCTs which were published up to May 31st, 2019. We used Modified Jadad Score system to evaluate the quality of each included RCT. The pooled effects were estimated using random-effects model and presented as standardized mean differences with 95% confidence intervals.

RESULTS

A total of 12 RCTs were included in this meta-analysis. There was no significant difference in glucose control outcomes comparing fish oil supplementation to placebo. The effect size of fasting plasma glucose (FPG) was 0.13 (95% CI: - 0.03 to 0.28, p > 0.05). No marked change was observed in fasting insulin (FINS), glycosylated hemoglobin (HbA1c), and HOMA of insulin resistance (HOMA-IR) levels. Fish oil supplementation was associated with a decrease of triglyceride (TG) level by - 0.40 (95%CI: - 0.53 to - 0.28, p < 0.05), and an increase of high density lipoprotein (HDL) cholesterol level by 0.21 (95%CI: 0.05 to 0.37, p < 0.05). In subgroup analysis, HDL cholesterol level was higher among Asian and low-dose(< 2 g/d n-3 PUFA) subgroups compared to their counterparts (p < 0.05). TG level was lower in mid and long duration groups, along with an inconspicuous difference in short duration group.

CONCLUSIONS

This meta-analysis shows that among patients with T2DM, fish oil supplementation leads to a favorable blood lipids profile but does not improve glucose control.

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.

Omega-3 Fatty Acids Effects on Inflammatory Biomarkers and Lipid Profiles among Diabetic and Cardiovascular Disease Patients: A Systematic Review and Meta-Analysis

The purpose of this systematic review and meta-analysis was to investigate omega-3 fatty acids’ influence on 12 inflammatory biomarkers—LDL, HDL, total cholesterol, TG, HbA1c, Apo AI, Apo AII, Apo B, CRP, TNF-α, glucose, and fasting blood glucose among diabetic and cardiovascular disease (CVD) patients. We searched articles in six database engines, and 16 of the 696 articles reviewed met the inclusion criteria. Among these, lipid and inflammatory biomarkers investigated commonly included total cholesterol (11 studies), LDL, and TG (10 studies each). Overall, omega-3 was associated with a significant reduction in Apo AII among diabetic patients, as compared to different controls (−8.0 mg/dL 95% CI: −12.71, −3.29, p = 0.0009), triglycerides (−44.88 mg/dL 95% CI: −82.6, −7.16, p < 0.0001), HDL (−2.27 mg/dL 95% CI: −3.72, −0.83, p = 0.002), and increased fasting blood glucose (16.14 mg/dL 95% CI: 6.25, 26.04, p = 0.001). Omega-3 also was associated with increased LDL among CVD patients (2.10 mg/dL 95% CI: 1.00, 3.20, p = 0.0002). We conclude that omega-3 fatty acids may be associated with lower inflammatory biomarkers among diabetic and cardiovascular patients. Clinicians should be aware of these potential benefits; however, it is essential to recommend that patients consult with clinicians before any omega-3 intake.

Vitamin D and omega-3 trial to prevent and treat diabetic kidney disease: Rationale, design, and baseline characteristics

Diabetic kidney disease (DKD), defined as reduced glomerular filtration rate (GFR), elevated urine albumin excretion, or both that is clinically attributable to diabetes, is a common and morbid diabetes complication. Animal-experimental data, observational human studies, and short-term clinical trials suggest that vitamin D and omega-3 fatty acid supplements may be safe and inexpensive interventions to reduce the incidence and progression of DKD. The Vitamin D and Omega-3 Trial to Prevent and Treat DKD (VITAL-DKD) was designed as an ancillary study to the VITAL trial of 25,871 US adults. In a 2 × 2 factorial design, VITAL participants were randomly assigned to vitamin D₃ (cholecalciferol, 2000 IU daily) or placebo and to marine omega-3 fatty acids (eicospentaenoic acid and docosahexaenoic acid, 1 g/d) or placebo. VITAL-DKD enrolled a subset of 1326 VITAL participants with type 2 diabetes at baseline to test the effects of vitamin D and omega-3 fatty acids on changes in estimated GFR and urine albumin excretion. Over five years of follow-up, VITAL-DKD collected blood and urine samples to quantify changes in estimated GFR (the primary study outcome) and urine albumin excretion. At baseline, mean age of VITAL-DKD participants was 67.6 years, 46% were women, 30% were of racial or ethnic minority, and the prevalence of DKD (estimated GFR <60 mL/min/1.73m² or urine albumin-creatinine ratio ≥ 30 mg/g) was 17%. In this type 2 diabetes population, VITAL-DKD will test the hypotheses that vitamin D and omega-3 fatty acids help prevent the development and progression of DKD.

Plasma polyunsaturated fatty acid profile is associated with vascular endothelial function in patients with type 2 diabetes

Decreased plasma n-3 polyunsaturated fatty acid levels or the n-3/n-6 polyunsaturated fatty acid ratios are associated with a risk of cardiovascular events. In this cross-sectional study, we measured plasma levels of eicosapentaenoic acid, docosahexaenoic acid, and arachidonic acid and investigated the association between the plasma polyunsaturated fatty acid profile and vascular endothelial function in 396 patients with type 2 diabetes. Endothelium-dependent, flow-mediated dilatation of the brachial artery was measured using ultrasonography. Multiple regression analyses, including age, sex, body mass index, and other cardiovascular risk factors, revealed that plasma eicosapentaenoic acid levels ( β = 0.140, p = 0.008) and the eicosapentaenoic acid/arachidonic acid ratio ( β = 0.127, p = 0.019), but not plasma docosahexaenoic acid levels ( β = 0.067, p = 0.220) or the docosahexaenoic acid/arachidonic acid ratio ( β = 0.034, p = 0.559), were independently and positively associated with flow-mediated dilatation. In conclusion, plasma eicosapentaenoic acid levels and the eicosapentaenoic acid/arachidonic acid ratio are independently associated with endothelial function in patients with type 2 diabetes. This study indicates a positive association between eicosapentaenoic acid, rather than docosahexaenoic acid, and endothelial function in type 2 diabetes.

Treatment with omega-3 polyunsaturated fatty acids does not improve endothelial function in patients with type 2 diabetes and very high cardiovascular risk: A randomized, double-blind, placebo-controlled study (Omega-FMD)

BACKGROUND AND AIMS

Numerous recent studies conducted in different clinical settings have focused on the benefits of omega-3 polyunsaturated fatty acids (n-3 PUFAs) in the prevention of cardiovascular diseases. There is limited evidence that patients with type 2 diabetes (T2D) and very high cardiovascular risk can also benefit from a high dose of n-3PUFAs, especially those on optimal medical therapy as recommended by the guidelines. The aim of the present study was to assess the impact of high-dose n-3 PUFA treatment on endothelial function in patients with T2D and established atherosclerotic cardiovascular disease (ASCVD).

METHODS

We conducted a prospective randomized double-blind, placebo-controlled, 2-center study, in which endothelial function was measured using flow-mediated dilation (FMD) and nitroglycerin-mediated dilation (NMD). Serum fatty acids composition was measured by gas chromatography. All measurements were done at baseline and after 3 months of treatment with PUFAs at a dose of 2 g/d (n = 36) or placebo (n = 38).

RESULTS

The majority of the study population was treated with optimal medical therapy. Despite significantly higher concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid in the n-3 PUFA group after 3-month treatment, we did not observe significant changes in endothelial function indices (FMD and NMD). However, in regression analysis, only baseline FMD was associated with EPA concentration before 3 months of n-3 PUFA treatment.

CONCLUSIONS

Three months of high-dose n-3 PUFA treatment in very high-risk patients with ASCVD and T2D did not improve the endothelial function indices.

There Is No Impact of Diabetes on the Endothelial Function of Chronic Kidney Disease Patients

BACKGROUND

Patients with chronic kidney disease (CKD) and type 2 diabetes mellitus (DM) have increased risk of endothelial dysfunction, cardiovascular disease, and mortality. Several studies have separately analyzed endothelial function in these populations. However, data of patients with both CKD and DM are scarce. The aim of this study was to evaluate whether the presence of DM has any additional effect on the endothelial dysfunction of CKD patients.

METHODS

We measured endothelial progenitor cells (EPCs), stromal-derived factor 1 alpha (SDF-1α), serum and urinary nitric oxide (NO), flow-mediated dilation (FMD), and pulse wave velocity (PWV) in 37 CKD patients with DM (CKD-DM group) and in 37 without DM (CKD group).

RESULTS

CKD-DM group had a higher prevalence of obesity (P < 0.01), previous myocardial infarction (P = 0.02), myocardial revascularization (P = 0.04), and a trend for more peripheral artery disease (P = 0.07). Additionally, CKD-DM group had higher EPC (P = 0.001) and PWV (P < 0.001) values. On the other hand, no difference in SDF-1α and serum or urinary NO and FMD was observed between the groups.

CONCLUSIONS

Endothelial dysfunction is frequent in CKD patients, and an additive effect of diabetes cannot be implicated, suggesting the predominant role of uremia in this condition.

Dietary program and physical activity impact on biochemical markers in patients with type 2 diabetes: A systematic review

Objectives

Evaluate the effectiveness of the implementation of independently or combined dietary and physical activity programs on the blood glucose values and lipid profile in patients with type 2 diabetes, including participants aged 60 years and over.

Design

Systematic review.

Data source

PubMed/Medline database, with language restrictions. Papers published between 2010 and 2016 were included.

Study selection

A total of 30 randomised controlled trials were included that focused on physical activity and dietary interventions in patients with type 2 diabetes mellitus and include participants aged 60 years and over.

Results

The selected articles have shown that the implementation of physical activity programs (aerobic, resistance, flexibility and combined exercises), and programs based on a higher intake of vegetables, grains, legumes, fruits, unsaturated fatty acids, as well as consumption of foods with low glycaemic index, calorie restriction, intake of probiotics, vitamin D supplementation and educational sessions about diabetes improves blood glucose levels, as well as the lipid profile, in patients with type 2 diabetes.

Conclusions

Physical activity and dietary programs are fundamental in the treatment and metabolic control of type 2 diabetes mellitus.

Omega-3 polyunsaturated fatty acids improve endothelial function in humans at risk for atherosclerosis: A review

Epidemiology studies and clinical trials show that omega-3 polyunsaturated fatty acids (n-3 PUFAs) can prevent atherosclerotic morbidity and evidence suggests this may be mediated by improving endothelial dysfunction. Endothelial dysfunction is characterized by reduced vasodilation and a pro-inflammatory, pro-thrombotic state, and is an early pathological event in the development of atherosclerosis. Flow-mediated dilation (FMD), a gold standard for assessing endothelial dysfunction, is a predictor of future cardiovascular events and coronary heart disease risk. Notably, risk factors for endothelial dysfunction include classic risk factors for atherosclerosis: Elevated lipids, diabetes, hypertension, elevated BMI, cigarette smoking, and metabolic syndrome. In this paper, we review the ability of n-3 PUFAs to improve endothelial dysfunction in individuals with classic risk factors for atherosclerosis, but lacking diagnosed atherosclerotic disease, with the goal of identifying those individuals that might gain the most vasoprotection from n-3 PUFA supplements. We include trials using eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), or alpha-linolenic acid (ALA) alone, or EPA+DHA; and assessing endothelial function by FMD, forearm blood flow, or peripheral arterial tonometry. We found that n-3 PUFAs improved endothelial dysfunction in 16 of 17 studies in individuals with hyperlipidemia, elevated BMI, metabolic syndrome, or that smoked cigarettes, but only in 2 of 5 studies in diabetics. Further, these trials showed that use of EPA+DHA consistently improve endothelial dysfunction; ALA-enriched diets appear promising; but use of EPA or DHA alone requires further study. We conclude that individuals with hyperlipidemia, elevated BMI, metabolic syndrome, or that smoke could derive vaosprotective benefits from EPA+DHA supplementation.

Eicosapentaenoic acid and docosahexaenoic acid containing supplements modulate risk factors for cardiovascular disease: a meta-analysis of randomised placebo-control human clinical trials

BACKGROUND

Over 200 clinical trials have examined the effect of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplements on risk factors associated with cardiovascular disease. However, an updated analysis of the evidence is lacking. The aim of the present meta-analysis was to quantify the effect of supplements containing EPA and DHA on risk factors for cardiovascular disease.

METHODS

An analysis was carried on 171 clinical trials with acceptable quality (Jadad score ≥3) that were identified from a comprehensive electronic search strategy of two databases (Pubmed and Cochrane Library). A random effect model was used to obtain an overall estimate on outcomes of interest. Heterogeneity between trial results was tested for using a standard chi-squared test.

RESULTS

Compared with control, EPA and DHA supplements produced significant reductions of triglycerides of 0.368 mmol L^-1 [95% confidence interval (CI) = -0.427 to -0.309], systolic blood pressure of 2.195 mmHg (95% CI = -3.172 to -1.217), diastolic blood pressure of 1.08 mmHg (95% CI = -1.716 to -0.444), heart rate of 1.37 bpm (95% CI = -2.41 to -0.325) and C-reactive protein of 0.343 mg L^-1 (95% CI = -0.454 to -0.232). This analysis indicates an increase in both low-density lipoprotein cholesterol (mean difference = 0.150 mmol L^-1 ; 95% CI = 0.058-0.243) and high-density lipoprotein cholesterol (mean difference = 0.039 mmol L^-1 ; 95% CI = 0.024-0.054). The triglyceride-lowering effect was dose-dependent.

CONCLUSIONS

The lipid-lowering, hypotensive, anti-arrhythmic and anti-inflammatory actions of EPA and DHA supplements were confirmed in this analysis of randomised placebo-control blinded clinical trials.

Effect of n-3 Polyunsaturated Fatty Acid Supplementation on Metabolic and Inflammatory Biomarkers in Type 2 Diabetes Mellitus Patients

BACKGROUND

Type 2 diabetes mellitus (T2DM) is accompanied by chronic low-grade inflammation, with an imbalance in the secretion of adipokines and, worsening insulin resistance. Supplementation with n-3 PUFA in T2DM decreases inflammatory markers, the purpose of the study was to investigate the effect of n-3 PUFA supplementation on adipokines, metabolic control, and lipid profile in T2DM Mexican adults.

METHODS

In a randomized, single-blind, placebo-controlled pilot study, 54 patients with T2DM received 520 mg of DHA + EPA-enriched fish-oil (FOG) or a placebo (PG) daily. Baseline and 24-week anthropometric and biochemical measurements included glucose, insulin, glycosylated hemoglobin (Hb1Ac), leptin, adiponectin, resistin, and lipid profile; n-3 PUFA intake was calculated in g/day.

RESULTS

Waist circumference and blood glucose showed significant reductions in the FOG group (p = 0.001 and p = 0.011, respectively). Hb1Ac (p = 0.009 and p = 0.004), leptin (p < 0.000 and p < 0.000), and leptin/adiponectin ratio (p < 0.000 and p < 0.000) decreased significantly in both groups after 24 weeks (FOG and PG respectively). Serum resistin (FOG p < 0.000 and PG p = 0.001), insulin (FOG p < 0.000 and PG p < 0.000), and HOMA-IR (FOG p = 0.000 and PG p < 0.000) increased significantly in both groups. FOG had an overall improvement in the lipid profile with a significant decrease in triacylgycerols (p = 0.002) and atherogenic index (p = 0.031); in contrast, the PG group had increased total cholesterol (p < 0.000), non-HDL cholesterol (p < 0.000), and atherogenic index (p = 0.017).

CONCLUSIONS

We found a beneficial effect of n-3 PUFA supplementation on waist circumference, glucose, Hb1Ac, leptin, leptin/adiponectin ratio, and lipid profile, without significant changes in adiponectin, and increases in resistin, insulin, and HOMA-IR in both groups.

Effects of Long-Chain Omega-3 Polyunsaturated Fatty Acids on Endothelial Vasodilator Function and Cognition-Are They Interrelated?

Long-chain omega-3 polyunsaturated fatty acids (LCn-3 PUFA) may improve brain functions by acting on endothelial cells in the cerebrovasculature to facilitate vasodilatation and perfusion. The aim of this review is to explore this hypothesis by analyzing the effect of LCn-3 PUFA supplementation on systemic vasodilator and cognitive function and finding evidence to link LCn-3 PUFA intake, vasodilator function and cognition. Forty randomized controlled trials examining the effect of LCn-3 PUFA supplementation in humans on either endothelial vasodilator function or cognition were identified and pooled effects measured with a weighted analysis. Compared to placebo, LCn-3 PUFA tended to increase flow-mediated dilatation and significantly improved cognitive function. Emerging evidence links vasodilator dysfunction to cognitive impairment, but evidence that LCn-3 PUFA can improve cognition through enhancements of vasodilator function is still lacking. Further research is needed to determine: (1) whether LCn-3 PUFA can enhance dilatation of cerebral vessels; (2) if improvements in cerebrovascular responsiveness by LCn-3 PUFA are accompanied by cognitive benefits; and (3) the target population groups.

Treatment with high-dose n-3 PUFAs has no effect on platelet function, coagulation, metabolic status or inflammation in patients with atherosclerosis and type 2 diabetes

BACKGROUND

Despite numerous studies on cardioprotective effects of omega-3 polyunsaturated fatty acids (n-3 PUFAs), there is limited evidence for n-3 PUFA-mediated effects, especially at its higher dose, on cardiovascular risk in patients with type 2 diabetes (DM2) and established atherosclerosis.

PURPOSE

To investigate the effect of daily treatment with a higher dose (2 g) of n-3 PUFAs on platelet function, coagulation parameters, fibrin clot properties, markers of systemic inflammation and metabolic status, in patients with atherosclerotic vascular disease and DM2 who receive optimal medical therapy.

METHODS

We conducted a prospective, double-blind, placebo-controlled, randomized, double-center study, in which thrombin generation (plasma thrombogenic potential from automated thrombogram), fibrin clot properties (plasma fibrin clot permeability; lysis time), platelet aggregation (light transmission aggregometry with adenosine diphosphate and arachidonic acid used as agonists), HbA1c, insulin level, lipid profiles, leptin and adiponectin levels, as well as markers of systemic inflammation (i.e., hsCRP, IL-6, TNF-α, ICAM-1, VCAM-1, and myeloperoxidase) were determined at baseline and at 3 months after treatment with 2 g/day of n-3 PUFAs (n = 36) or placebo (n = 38). Moreover, we assessed serum fatty acids of the phospholipid fraction by gas chromatography both at baseline and at the end of the study.

RESULTS

Majority of patients were treated with optimal medical therapy and achieved recommended treatment targets. Despite higher serum levels of eicosapentaenoic acid (EPA) (by 204%; p < 0.001) and docosahexaenoic acid (DHA) (by 62%; p < 0.0001) in n-3 PUFA group at the end of treatment no changes in platelet aggregation, thrombin generation, fibrin clot properties or markers of systemic inflammation were observed. No intergroup differences in the insulin, HbA1c and lipid levels were found at the end of the study. There was no change in adiponectin and leptin in interventional group, however leptin increased in control group (p = 0.01), therefore after study period leptin levels were lower in the interventional group (p = 0.01). Additionally, resolvin D1 did not differ between interventional and control group.

CONCLUSIONS

In conclusion, our study demonstrated that in patients with long-standing, well-controlled DM2 and atherosclerotic disease the treatment with a high dose of n-3 PUFAs (namely, 1 g/day of EPA and 1 g/day of DHA for 3 months) does not improve coagulation, metabolic, and inflammatory status when measured with the specified tests. The study was registered in ClinicalTrials.gov; identifier: NCT02178501. Registration date: April 12, 2014.

Omega-3 fatty acids supplementation improves endothelial function and arterial stiffness in hypertensive patients with hypertriglyceridemia and high cardiovascular risk

Association between hypertriglyceridemia and cardiovascular (CV) disease is still controversial. The purpose of this study was to compare omega-3 and ciprofibrate effects on the vascular structure and function in low and high CV risk hypertensive patients with hypertriglyceridemia. Twenty-nine adults with triglycerides 150-499 mg/dL were divided into low (<7.5%) and high (≥7.5%) CV risk, randomized to receive omega-3 fatty acids 1800 mg/d or ciprofibrate 100 mg/d for 12 weeks. Treatment was switched after 8-week washout. Clinical evaluation and vascular tests were assessed at baseline and after intervention. Peripheral (131 ± 3 to 125 ± 3 mm Hg, P < .05) and aortic (124 ± 3 to 118 ± 2 mg/dL, P < .05) systolic blood pressure were decreased by ciprofibrate in low-risk patients. In high-risk patients, pulse wave velocity was reduced (10.4 ± 0.4 to 9.4 ± 0.3 m/s, P < .05) and flow-mediated dilation was increased (11.1 ± 1.6 to 13.5 ± 1.2%, P < .05) by omega-3. In conclusion, omega-3 improved arterial stiffness and endothelial function, pointing out the beneficial effect of this therapy on vascular aging, in high-risk patients.

What is the impact of n-3 PUFAs on inflammation markers in Type 2 diabetic mellitus populations?: a systematic review and meta-analysis of randomized controlled trials

Objectives

To explore the possible role of n-3 polyunsaturated fatty acids (PUFAs) in lowering inflammation markers in individuals with type 2 diabetes mellitus.

Methods

PubMed, CNKI and Cochrane databases were searched until December 30, 2015; references from papers or reviews were also retrieved and screened. Screening was performed by two independent researchers, and randomized controlled trials reporting the specific n-3 PUFA type, dose, frequency, and duration of treatment, as well as the baseline and follow-up concentrations of inflammation markers, including interleukin 2 (IL-2), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α) and C-reactive protein (CRP), were selected for final analysis. Data analysis was performed using RevMan 5.2 software.

Results

Eight studies involving 955 participants were included; all reported CRP. Only one included study reported IL-2 or IL-6 while two studies reported TNF-α. N-3 PUFAs significantly reduced CRP concentration compared with control [SMD 95 % CI, 1.90 (0.64, 3.16), Z = 2.96, P = 0.003, random effect model].

Conclusions

N-3 PUFAs decrease CRP concentration in type-2 diabetes mellitus. However, larger and rigorously designed RCTs are required to confirm this finding and extend it into other inflammatory biomarkers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-016-0303-7) contains supplementary material, which is available to authorized users.

Effects of Omega-3 Fatty Acid Supplementation on Glucose Control and Lipid Levels in Type 2 Diabetes: A Meta-Analysis

Background

Many studies assessed the impact of marine omega-3 fatty acids on glycemic homeostasis and lipid profiles in patients with type 2 diabetes (T2DM), but reported controversial results. Our goal was to systematically evaluate the effects of omega-3 on glucose control and lipid levels.

Methods

Medline, Pubmed, Cochrane Library, Embase, the National Research Register, and SIGLE were searched to identify eligible randomized clinical trials (RCTs). Extracted data from RCTs were analyzed using STATA 11.0 statistical software with fixed or random effects model. Effect sizes were presented as weighted mean differences (WMD) with 95% confidence intervals (95% CI). Heterogeneity was assessed using the Chi-square test with significance level set at p < 0.1.

Results

20 RCT trials were included into this meta-analysis. Among patients with omega-3 supplementation, triglyceride (TG) levels were significantly decreased by 0.24 mmol/L. No marked change in total cholesterol (TC), HbA1c, fasting plasma glucose, postprandial plasma glucose, BMI or body weight was observed. High ratio of EPA/DHA contributed to a greater decreasing tendency in plasma insulin, HbAc1, TC, TG, and BMI measures, although no statistical significance was identified (except TG). FPG levels were increased by 0.42 mmol/L in Asians. No evidence of publication bias was observed in this meta-analysis.

Conclusions

The ratio of EPA/DHA and early intervention with omega 3 fatty acids may affect their effects on glucose control and lipid levels, which may serve as a dietary reference for clinicians or nutritionists who manage diabetic patients.

Effects of Olive Oil on Markers of Inflammation and Endothelial Function-A Systematic Review and Meta-Analysis

The aim of the present systematic review was to synthesize data from randomized controlled trials investigating the effects of olive oil on markers of inflammation or endothelial function. Literature search in electronic databases Cochrane Trial Register, EMBASE, and MEDLINE was performed. Thirty studies enrolling 3106 participants fulfilled the selection criteria. Pooled effects of different interventions were assessed as mean difference using a random effects model. Olive oil interventions (with daily consumption ranging approximately between 1 mg and 50 mg) resulted in a significantly more pronounced decrease in C-reactive protein (mean difference: −0.64 mg/L, (95% confidence interval (CI) −0.96 to −0.31), p < 0.0001, n = 15 trials) and interleukin-6 (mean difference: −0.29 (95% CI −0.7 to −0.02), p < 0.04, n = 7 trials) as compared to controls, respectively. Values of flow-mediated dilatation (given as absolute percentage) were significantly more increased in individuals subjected to olive oil interventions (mean difference: 0.76% (95% CI 0.27 to 1.24), p < 0.002, n = 8 trials). These results provide evidence that olive oil might exert beneficial effects on endothelial function as well as markers of inflammation and endothelial function, thus representing a key ingredient contributing to the cardiovascular-protective effects of a Mediterranean diet. However, due to the heterogeneous study designs (e.g., olive oil given as a supplement or as part of dietary pattern, variations in control diets), a conservative interpretation of the results is necessary.

Omega-3 Polyunsaturated Fatty Acids: Structural and Functional Effects on the Vascular Wall

Omega-3 polyunsaturated fatty acids (n-3 PUFA) consumption is associated with reduced cardiovascular disease risk. Increasing evidence demonstrating a beneficial effect of n-3 PUFA on arterial wall properties is progressively emerging. We reviewed the recent available evidence for the cardiovascular effects of n-3 PUFA focusing on structural and functional properties of the vascular wall. In experimental studies and clinical trials n-3 PUFA have shown the ability to improve arterial hemodynamics by reducing arterial stiffness, thus explaining some of its cardioprotective properties. Recent studies suggest beneficial effects of n-3 PUFA on endothelial activation, which are likely to improve vascular function. Several molecular, cellular, and physiological pathways influenced by n-3 PUFA can affect arterial wall properties and therefore interfere with the atherosclerotic process. Although the relative weight of different physiological and molecular mechanisms and the dose-response on arterial wall properties have yet to be determined, n-3 PUFA have the potential to beneficially impact arterial wall remodeling and cardiovascular outcomes by targeting arterial wall stiffening and endothelial dysfunction.

Fish Oil Supplements Lower Serum Lipids and Glucose in Correlation with a Reduction in Plasma Fibroblast Growth Factor 21 and Prostaglandin E2 in Nonalcoholic Fatty Liver Disease Associated with Hyperlipidemia: A Randomized Clinical Trial

Fish oil has been used effectively in the treatment of cardiovascular disease via triglyceride reduction and inflammation modulation. This study aimed to assess the effects of fish oil on patients with nonalcoholic fatty liver disease (NAFLD) associated with hyperlipidemia. Eighty participants with NAFLD associated with hyperlipidemia were randomly assigned to consume fish oil (n=40, 4 g/d) or corn oil capsules (n=40, 4 g/d) for 3 months in a double-blind, randomized clinical trial. Blood levels of lipids, glucose and insulin, liver enzymes, kidney parameters and cytokines at baseline and the end of the study were measured. Seventy people finished the trial. Plasma concentrations of eicosapentaenoic acid and docosahexaenoic acid significantly increased in the fish oil group after intervention. After adjustment for age, gender and BMI, fish oil significantly decreased fasting serum concentrations of total cholesterol, triglyceride, apolipoprotein B and glucose (by (mean±SD) 0.49±0.43 mmol/L, 0.58±0.89 mmol/L, 0.28±0.33 g/L and 0.76±0.56 mmol/L, respectively, P<0.05), as well as alanine aminotransferase and γ-glutamyl transpeptidase levels (by (median (interquartile)) 9.0(0.5, 21.5) and 7.0(2.2, 20.0) IU/L, respectively, P<0.05), significantly increased serum adiponectin levels (by 1.29±0.62 μg/mL, P<0.001), and reduced serum levels of tumor necrosis factor α, leukotrienes B4, fibroblast growth factor 21 (FGF21), cytokeratin 18 fragment M30 and prostaglandin E2 (by 1.70±1.18 pg/mL, 0.59±0.28 ng/mL, 121±31 pg/mL, 83±60 IU/L and 10.9±2.3 pg/mL, respectively, P<0.001). Corn oil had no effect except for increasing serum creatinine concentrations by 7.7±8.9 μmol/L (P=0.008). The effects of fish oil on lipids, glucose and γ-glutamyl transpeptidase were positively correlated with the reductions of serum FGF21 and prostaglandin E2 concentrations after adjustment for age, gender and BMI (r = 0.275 to 0.360 and 0.261 to 0.375, respectively, P<0.05). In conclusion, our findings suggest that fish oil can benefit metabolic abnormalities associated with NAFLD treatment.

A select review reporting the quality of studies measuring endothelial dysfunction in randomised diet intervention trials

A quality assessment of the primary studies reported in the literature carried out using select dietary ingredients (DI) purported to affect vascular endothelial function was conducted through a systematic PubMed search from January 2000 to August 2012. A total of seventy randomised controlled trials with defined DI (folic acid (fifteen), n-3 fatty acids (twenty), cocoa (fifteen) and isoflavones (twenty)) and standardised measures of vascular endothelial function were evaluated. Jadad scores, quality scoring parameters for DI and flow-mediated dilation (FMD) methodology used were ascertained. A total of 3959 randomised subjects, mean age 51 (se 0·21) years (range 9-79 years), were represented in the dataset. The mean Jadad scores did not differ statistically among the DI studies, with the majority of the studies being of good quality. Higher DI quality scores were achieved by studies using the botanical ingredients cocoa and isoflavones than by those using the nutrient ingredients folic acid and n-3 fatty acids. The mean DI quality scores were 4·13 (se 0·34), 5·20 (se 0·47), 6·13 (se 0·41) and 6·00 (se 0·59) for the folic acid, n-3 fatty acid, cocoa and isoflavone intervention studies, respectively (and significantly different). The mean Corretti FMD scores were 7·27 (se 0·56), 7·46 (se 0·79), 6·29 (se 0·61) and 7·11 (se 0·56) for the folic acid, n-3 fatty acid, cocoa and isoflavone intervention studies, respectively (NS). FMD studies failed to adequately describe the equipment used and more than half failed to provide an adequate description of the procedures used for vascular image acquisition and measurement. DI can be utilised for dietary intervention studies; however, the methodology should be clearly reported using the guidelines for assessment for both DI and FMD.

Fish-oil supplementation alters numbers of circulating endothelial progenitor cells and microparticles independently of eNOS genotype

BACKGROUND

Emerging cellular markers of endothelial damage and repair include endothelial microparticles (EMPs) and endothelial progenitor cells (EPCs), respectively. Effects of long-chain (LC) n-3 (omega-3) polyunsaturated fatty acids (PUFAs) and the influence of genetic background on these markers are not known.

OBJECTIVE

We investigated effects of fish-oil supplementation on both classical and novel markers of endothelial function in subjects prospectively genotyped for the Asp298 endothelial nitric oxide synthase (eNOS) polymorphism and at moderate risk of cardiovascular disease (CVD).

DESIGN

A total of 84 subjects with moderate risk of CVD (GG: n = 40; GT/TT: n = 44) completed a randomized, double-blind, placebo-controlled, 8-wk crossover trial of fish-oil supplementation that provided 1.5 g LC n-3 PUFAs/d. Effects of genotype and fish-oil supplementation on the blood lipid profile, inflammatory markers, vascular function (by using peripheral artery tonometry), and numbers of circulating EPCs and EMPs (by using flow cytometry) were assessed.

RESULTS

There was no significant effect of fish-oil supplementation on blood pressure, plasma lipids, or plasma glucose, although there was a trend (P = 0.069) toward a decrease in the plasma triglyceride concentration after fish-oil supplementation compared with placebo treatment. GT/TT subjects tended to have higher concentrations of total cholesterol and low-density lipoprotein cholesterol, but vascular function was not affected by either treatment or eNOS genotype. Biochemical markers of endothelial function were also unaffected by treatment and eNOS genotype. In contrast, there was a significant effect of fish-oil supplementation on cellular markers of endothelial function. Fish-oil supplementation increased numbers of EPCs and reduced numbers of EMPs relative to those with placebo treatment, which potentially favored the maintenance of endothelial integrity. There was no influence of genotype for any cellular markers of endothelial function, which indicated that effects of fish-oil supplementation were independent of eNOS genotype.

CONCLUSION

Emerging cellular markers of endothelial damage, integrity, and repair appear to be sensitive to potentially beneficial modification by dietary n-3 PUFAs. This trial was registered at www.controlled-trials.com/isrctn as ISRCTN76272133.

Grain and bean lysates improve function of endothelial progenitor cells from human peripheral blood: involvement of the endogenous antioxidant defenses

Increased oxidative stress contributes to the functional impairment of endothelial progenitor cells (EPCs), the pivotal players in the servicing of the endothelial cell lining. Several evidences suggest that decreasing oxidative stress by natural compounds with antioxidant properties may improve EPCs bioactivity. Here, we investigated the effects of Lisosan G (LG), a Triticum Sativum grain powder, and Lady Joy (LJ), a bean lysate, on function of EPCs exposed to oxidative stress. Peripheral blood mononuclear cells were isolated and plated on fibronectin-coated culture dishes; adherent cells, identified as early EPCs, were pre-treated with different concentrations of LG and LJ and incubated with hydrogen peroxide (H2O2). Viability, senescence, adhesion, ROS production and antioxidant enzymes gene expression were evaluated. Lysate-mediated Nrf-2 (nuclear factor (erythroid-derived 2)-like 2)/ARE (antioxidant response element) activation, a modulator of oxidative stress, was assessed by immunocytochemistry. Lady Joy 0.35-0.7 mg/ml increases EPCs viability; pre-treatment with either LG 0.7 mg/ml and LJ 0.35-0.7 mg/ml protect EPCs viability against H2O2-induced injury. LG 0.7 and LJ 0.35-0.7 mg/ml improve EPCs adhesion; pre-treatment with either LG 0.35 and 0.7 mg/ml or LJ 0.35, 0.7 and 1.4 mg/ml preserve adhesiveness of EPCs exposed to H2O2. Senescence is attenuated in EPCs incubated with lysates 0.35 mg/ml. After exposure to H2O2, LG pre-treated cells show a lower senescence than untreated EPCs. Lysates significantly decrease H2O2-induced ROS generation. Both lysates increase glutathione peroxidase-1 and superoxide dismutase-2 (SOD-2) expression; upon H2O2 exposure, pre-treatment with LJ allows higher SOD-2 expression. Heme oxigenase-1 increases in EPCs pre-treated with LG even upon H2O2 exposure. Finally, incubation with LG 0.7 mg/ml results in Nrf-2 translocation into the nucleus both at baseline and after the oxidative challenge. Our data suggest a protective effect of lysates on EPCs exposed to oxidative stress through the involvement of antioxidant systems. Lisosan G seems to activate the Nrf-2/ARE pathways.

Reduced dietary omega-6 to omega-3 fatty acid ratio and 12/15-lipoxygenase deficiency are protective against chronic high fat diet-induced steatohepatitis

Obesity is associated with metabolic perturbations including liver and adipose tissue inflammation, insulin resistance, and type 2 diabetes. Omega-6 fatty acids (ω6) promote and omega-3 fatty acids (ω3) reduce inflammation as they can be metabolized to pro- and anti-inflammatory eicosanoids, respectively. 12/15-lipoxygenase (12/15-LO) enzymatically produces some of these metabolites and is induced by high fat (HF) diet. We investigated the effects of altering dietary ω6/ω3 ratio and 12/15-LO deficiency on HF diet-induced tissue inflammation and insulin resistance. We examined how these conditions affect circulating concentrations of oxidized metabolites of ω6 arachidonic and linoleic acids and innate and adaptive immune system activity in the liver. For 15 weeks, wild-type (WT) mice were fed either a soybean oil-enriched HF diet with high dietary ω6/ω3 ratio (11∶1, HFH), similar to Western-style diet, or a fat Kcal-matched, fish oil-enriched HF diet with a low dietary ω6/ω3 ratio of 2.7∶1 (HFL). Importantly, the total saturated, monounsaturated and polyunsaturated fat content was matched in the two HF diets, which is unlike most published fish oil studies in mice. Despite modestly increased food intake, WT mice fed HFL were protected from HFH-diet induced steatohepatitis, evidenced by decreased hepatic mRNA expression of pro-inflammatory genes and genes involved in lymphocyte homing, and reduced deposition of hepatic triglyceride. Furthermore, oxidized metabolites of ω6 arachidonic acid were decreased in the plasma of WT HFL compared to WT HFH-fed mice. 12/15-LO knockout (KO) mice were also protected from HFH-induced fatty liver and elevated mRNA markers of inflammation and lymphocyte homing. 12/15-LOKO mice were protected from HFH-induced insulin resistance but reducing dietary ω6/ω3 ratio in WT mice did not ameliorate insulin resistance or adipose tissue inflammation. In conclusion, lowering dietary ω6/ω3 ratio in HF diet significantly reduces steatohepatitis.

Effect of omega-3 fatty acids on kidney function after myocardial infarction: the Alpha Omega Trial

BACKGROUND AND OBJECTIVES

Kidney function gradually decreases with age, and myocardial infarction accelerates this deterioration. Omega-3 (n-3) fatty acids may slow down the decline of kidney function. The effect of marine and plant-derived n-3 fatty acids on kidney function in patients after myocardial infarction was examined.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In the Alpha Omega Trial, 2344 patients with history of myocardial infarction ages 60-80 years old (81% men) were randomized to one of four trial margarines. The patients received an additional targeted amount of 400 mg/d eicosapentaenoic acid and docosahexaenoic acid, 2 g/d α-linolenic acid, eicosapentaenoic acid-docosahexaenoic acid plus α-linolenic acid, or placebo for 40 months. Serum cystatin C and serum creatinine were assessed at baseline and after 40 months. Creatinine-cystatin C-based GFR was estimated with the Chronic Kidney Disease Epidemiology Collaboration equation.

RESULTS

Patients consumed 19.9 g margarine/d, providing an additional 239 mg/d eicosapentaenoic acid with 159 mg/d docosahexaenoic acid, 1.99 g/d α-linolenic acid, or both in the active treatment groups. After 40 months, compared with baseline, mean (±SD) creatinine-cystatin C-based GFR was -6.9 (±12.6), -4.8 (±13.4), -6.2 (±12.8), and -6.0 (±13.0) ml/min per 1.73 m(2) in the placebo, eicosapentaenoic acid-docosahexaenoic acid, α-linolenic acid, and eicosapentaenoic acid-docosahexaenoic acid plus α-linolenic acid groups, respectively. After 40 months, in patients receiving eicosapentaenoic acid-docosahexaenoic acid compared with placebo, the decline in creatinine-cystatin C-based GFR was 2.1 less (95% confidence interval, 0.6 to 3.6; P<0.01) ml/min per 1.73 m(2); other comparisons were not statistical significant. Odds ratios (95% confidence intervals) of incident CKD (<60 ml/min per 1.73 m(2)) and rapid decline of kidney function (≥3 ml/min per year) for eicosapentaenoic acid-docosahexaenoic acid compared with placebo were 0.83 (0.58 to 1.18) and 0.85 (0.67 to 1.08), respectively.

CONCLUSIONS

Long-term supplementation with 400 mg/d eicosapentaenoic acid-docosahexaenoic acid provides a small beneficial effect on kidney function in patients with a history of myocardial infarction.

Association of n-3 polyunsaturated fatty acids and inflammatory indicators with renal function decline in type 2 diabetes

BACKGROUND & AIMS

The n-3 polyunsaturated fatty acids (PUFAs) and the inflammatory indicator, interleukin-6 (IL-6), have been implied in the development of renal dysfunction. This longitudinal study examined the effect of n-3 PUFAs and IL-6 on the risk of renal function decline and explored whether n-3 PUFAs modify the effect of inflammatory indicators on renal dysfunction risk in type 2 diabetes.

METHODS

Studying 676 type 2 diabetic patients, we analyzed erythrocyte fatty acids and inflammatory markers in 2008 and estimated glomerular filtration rate (eGFR) in 2008 and 2012. Renal function decline was defined as an eGFR decline of ≥25% over a 4-year period.

RESULTS

Multivariable logistic regression revealed erythrocyte total PUFAs, n-3 PUFAs, and n-3/n-6 PUFA ratio correlated negatively with risk of renal function decline (OR = 0.75, 0.78, and 0.61, respectively, all p < 0.01), while n-6 PUFAs did not. IL-6 independently predicted risk of renal dysfunction (OR = 1.18, p = 0.015). Stratifying erythrocyte PUFAs into low (<50(th) percentile) or high group (≥50(th) percentile), we found a positive association between IL-6 and risk of renal dysfunction only in the low n-3 PUFA (OR = 1.27, p = 0.035), low n-3/n-6 PUFA (OR = 1.27, p = 0.034), and low total PUFA groups (OR = 1.36, p = 0.005), but not in the high groups.

CONCLUSIONS

High PUFA concentrations, especially n-3 or higher n-3/n-6 PUFA ratio, may exert protective effects against renal function impairment in type 2 diabetic patients. Whether the effect is mediated via modification of inflammatory biomarker such as IL-6 by high n-3 PUFA status warrants further investigation.

Effect of marine-derived n-3 polyunsaturated fatty acids on C-reactive protein, interleukin 6 and tumor necrosis factor α: a meta-analysis

Background

Previous studies did not draw a consistent conclusion about the effects of marine-derived n-3 polyunsaturated fatty acids (PUFAs) on fasting blood level of C-reactive protein (CRP), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α).

Methods and Findings

A comprehensive search of Web of Science, PubMed, Embase and Medline (from 1950 to 2013) and bibliographies of relevant articles was undertaken. Sixty-eight RCTs with a total of 4601 subjects were included in the meta-analysis. Marine-derived n-3 PUFAs supplementation showed a lowering effect on Marine-derived n-3 PUFAs supplementation had a significant lowering effect on TNF-α, IL-6 and CRP in three groups of subjects (subjects with chronic non-autoimmune disease, subjects with chronic autoimmune disease and healthy subjects). A significant negative linear relationship between duration and effect size of marine-derived n-3 PUFAs supplementation on fasting blood levels of TNF-α and IL-6 in subjects with chronic non-autoimmune disease was observed, indicating that longer duration of supplementation could lead to a greater lowering effect. A similar linear relationship was also observed for IL-6 levels in healthy subjects. Restricted cubic spline analysis and subgroup analysis showed that the lowering effect of marine-derived n-3 PUFAs on CRP, IL-6 and TNF-α in subjects with chronic non-autoimmune disease became weakened when body mass index was greater than 30 kg/m². The effect of marine-derived n-3 PUFAs from dietary intake was only assessed in subjects with chronic non-autoimmune disease, and a significant lowering effect was observed on IL-6, but not on CRP and TNF-α.

Conclusions

Marine-derived n-3 PUFAs supplementation had a significant lowering effect on CRP, IL-6 and TNF-α level. The lowering effect was most effective in non-obese subjects and consecutive long-term supplementation was recommended.