Omega-3 fatty acids improve postprandial lipemia and associated endothelial dysfunction in healthy individuals - a randomized cross-over trial

Effects of omega-3, omega-6, and total dietary polyunsaturated fatty acid supplementation in patients with atherosclerotic cardiovascular disease: a systematic review and meta-analysis

Background: Uncertainty exists about the link between omega-3 fatty acid, omega-6 fatty acid, and total polyunsaturated fatty acid (PUFA) intake and mortality in atherosclerotic cardiovascular disease (ASCVD) patients, and no meta-analyses summarize the relationship between these various types of PUFAs and ASCVD. Methods: Web of Science, PubMed, EBSCO and Cochrane Library up to November 30, 2022 were searched for prospective randomized controlled studies investigating the relationships among omega-3, omega-6, and PUFA intake and mortality and cardiovascular events in ASCVD patients. This study has been registered at PROSPERO (No. CRD42023407566). Results: This meta-analysis included 21 publications from 17 studies involving 40 861 participants published between 1965 and 2022. In ASCVD patients, omega-3 may lower all-cause mortality (RR: 0.90, 95% CI [0.83, 0.98], I2 = 8%), CVD mortality (RR: 0.82, 95% CI [0.73, 0.91], I2 = 34%) and CVD events (RR: 0.90, 95% CI [0.86, 0.93], I2 = 79%). Subgroup analyses showed that EPA or EPA ethyl ester supplementation reduced CVD events, while the mixture of EPA and DHA had no significant impact. Long-chain omega-3 consumption of 1.0-4.0 g per d reduced death risk by 3.5% for each 1 g per d increase. Omega-6 and PUFA had no significant effect on mortality or CVD events, with low-quality evidence and significant heterogeneity. Conclusions: omega-3 intake is associated with a reduced risk of all-cause mortality, CVD mortality, and CVD events in ASCVD patients, while omega-6 or total PUFA intake showed no significant association. Increasing the omega-3 intake by 1 g per d resulted in a 3.5% decrease in the risk of death. These findings support the recommendation of supplements with omega-3 fatty acids for the secondary prevention of ASCVD.

Current Evidence and Future Directions of Omega-3 Supplementation and Cardiovascular Disease Risk

Omega-3 supplementation has a controversial role in the secondary prevention of cardiovascular diseases. Despite large clinical trials published over the years, the evidence of omega-3 in preventing cardiovascular diseases, especially coronary heart disease, is still inconclusive. However, recent clinical trials using higher dose of omega-3 or highly purified esters of omega-3 shows promising result, with reduction in cardiovascular death and incidence of cardiovascular disease. This review aims to summarize the possible mechanism of omega-3 in preventing cardiovascular disease and future directions of research regarding the benefit of omega-3 in cardiovascular disease.

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.

Differential Effects of Two Isocaloric Healthy Diets on Postprandial Lipid Responses in Individuals with Type 2 Diabetes

BACKGROUND

High blood concentrations of triglycerides (TG) in the postprandial period have been shown to be more closely associated with the risk of cardiovascular disease (CVD) than fasting values in individuals with type 2 diabetes (T2D). Dietary changes are the primary determinants of postprandial lipid responses.

METHODS

We investigated the effects of an isocaloric multifactorial diet, rich in n-3 PUFA, MUFA, fiber, polyphenols, and vitamins, compared to an isocaloric diet, containing the same amount of MUFA, on the postprandial lipid response in T2D individuals. Following a randomized, controlled, parallel group design, 43 (25 male/18 female) T2D individuals were assigned to an isocaloric multifactorial (n = 21) or a MUFA-rich diet (n = 22). At the beginning and after the 8 weeks of dietary intervention, the concentrations of plasma triglycerides, total cholesterol, HDL cholesterol, and non-HDL cholesterol were detected at fasting and over a 4-h test meal with the same composition as the prescribed diet.

RESULTS

The concentrations of fasting plasma triglycerides, total cholesterol, HDL cholesterol, and non-HDL cholesterol did not change after both diets. Compared with the MUFA diet, the 8-week multifactorial diet significantly lowered the postprandial response, which was evaluated as the incremental area under the curve (iAUC), of triglycerides by 33% (64 ± 68 vs. 96 ± 50 mmol/L·240 min, mean ± SD, respectively, p = 0.018), total cholesterol by 105% (-51 ± 33 vs. -25 ± 29, p = 0.013), and non-HDL cholesterol by 206% (-39 ± 33 vs. -13 ± 23, p = 0.013).

CONCLUSIONS

In T2D individuals, a multifactorial diet, characterized by several beneficial components, improved the postprandial lipid response compared to a MUFA diet, generally considered a healthy diet being reduced in saturated fat, and probably contributed to the reduction of cardiovascular risk.

Bean and Nut Intake Were Protective Factors for Comorbid Hypertension and Hyperuricemia in Chinese Adults: Results from China Nutrition and Health Surveillance (2015-2017)

This study aimed to describe the prevalence of comorbid hypertension and hyperuricemia (HH) and detected the dietary factors for HH in Chinese adults aged 18 to 64 years. All of the data were collected from the China Nutrition and Health Surveillance 2015-2017, with a stratified, multistage, random sampling method on a national scale. A total of 52,627 adult participants aged 18~64 years from the CNHS 2015-2017 were included in this study. HH was identified as SUA level cut-offs for males and females of 420 μmol/L and 360 μmol/L, respectively, with mean systolic blood pressure ≥140 mmHg and/or mean diastolic blood pressure ≥ 90 mmHg and/or received antihypertensive treatment within two weeks. The differences in HH prevalence between or among the subgroups were compared by the Rao-Scott chi-square test. The correlations between HH and covariates or metabolic factors were detected by a weighted two-level multivariate survey logistic regression. The total weighted sufficient intake ratios of beans and nuts, vegetables, and red meat were 59.1%, 46.6%, and 64.8%, respectively. The weighted prevalence of HH in the total participants was 4.7% (95% CI: 4.3-5.0%). The positive effects of bean and nut on HH were observed. The participants who had sufficient bean and nut intake showed lower risk for HH (for the total participants: OR = 0.734, 95% CI = 0.611-0.881). The prevalence of HH might have been a public health problem, and bean and nut intake might be a protective factor for HH in the Chinese population.

An acute exercise at low to moderate intensity attenuated postprandial lipemia and insulin responses

Objective

The purpose of this study was to investigate the effects of different exercise intensities on postprandial lipemia (PHTG) and insulin resistance in healthy individuals.

Methods

Participants were 10 adult males with normal fasting triglyceride (TG) concentrations (age = 34 ± 2.8 y, body mass = 72.9 ± 2.4 kg, fasting plasma TG = 1.36 ± 0.18 mmol/l, VO2max = 43.7 ± 3.0 ml/kg/min, fasting glucose = 5.2 ± 0.2 mmol/l and fasting Homeostatic Model Assessment for Insulin Resistance (HOMA2-IR) = 1.7 ± 0.3). In this study, each participant performed a control trial (Ctr, no exercise), and 3 exercise trials at 40 % (40%T), 60 % (60%T), and 70 % (70%T) of their VO2max. In the exercise trials, participant jogged on a treadmill for 1 h at a designated intensity. A fat-rich meal was consumed by each participant 12 h after exercise. Blood samples were taken at 0 h (before the meal), and 2 h, 4 h, 6 h, 8 h, and 24 h after the meal. The plasma TG, area score under TG concentration curve over an 8 h-period (TG tAUC) after the meal, and HOMA2-IR were analyzed.

Results

Our results showed that at 2 h, 4 h, and 6 h after the meal, TG in all exercise trials were lower than Ctr (p < 0.05) but did not differ from each other. All the exercise trials were lower in TG tAUC scores than Ctr (p < 0.02), but differences were not observed among the exercise trials. In comparison to Ctr, a significant difference in HOMA2-IR in both 60 % T and 70 % T (p < 0.05 and p < 0.01, respectively) was observed, but not in 40 % T.

Conclusion

The results suggest that exercising at low to moderate exercise intensity for 1 h sufficiently attenuates a fat meal induced PHTG. Moderate exercise intensity also effectively mitigates insulin resistance.

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.

Animal and plant-based proteins have different postprandial effects on energy expenditure, glycemia, insulinemia, and lipemia: A review of controlled clinical trials

Dietary proteins have been shown to stimulate thermogenesis, increase satiety, and improve insulin sensitivity in the short and long term. Animal-based proteins (AP) and plant-based proteins (PP) have different amino acid profiles, bioavailability, and digestibility, so it seems to have various short- and long-term effects on metabolic responses. This review aimed to compare the findings of controlled clinical trials on postprandial effects of dietary Aps versus PPs on energy expenditure (EE), lipemia, glycemia, and insulinemia. Data are inconclusive regarding the postprandial effects of APs and PPs. However, there is some evidence indicating that APs increase postprandial EE, DIT, and SO more than PPs. With lipemia and glycemia, most studies showed that APs reduce or delay postprandial glycemia and lipemia and increase insulinemia more than PPs. The difference in amino acid composition, digestion and absorption rate, and gastric emptying rate between APs and PPs explains this difference.

Endothelial Glycocalyx Preservation-Impact of Nutrition and Lifestyle

The endothelial glycocalyx (eGC) is a dynamic hair-like layer expressed on the apical surface of endothelial cells throughout the vascular system. This layer serves as an endothelial cell gatekeeper by controlling the permeability and adhesion properties of endothelial cells, as well as by controlling vascular resistance through the mediation of vasodilation. Pathogenic destruction of the eGC could be linked to impaired vascular function, as well as several acute and chronic cardiovascular conditions. Defining the precise functions and mechanisms of the eGC is perhaps the limiting factor of the missing link in finding novel treatments for lifestyle-related diseases such as atherosclerosis, type 2 diabetes, hypertension, and metabolic syndrome. However, the relationship between diet, lifestyle, and the preservation of the eGC is an unexplored territory. This article provides an overview of the eGC's importance for health and disease and describes perspectives of nutritional therapy for the prevention of the eGC's pathogenic destruction. It is concluded that vitamin D and omega-3 fatty acid supplementation, as well as healthy dietary patterns such as the Mediterranean diet and the time management of eating, might show promise for preserving eGC health and, thus, the health of the cardiovascular system.

A single, high-fat meal adversely affects postprandial endothelial function: a systematic review and meta-analysis

BACKGROUND

Endothelial dysfunction is a predictive risk factor for the development of atherosclerosis and is assessed by flow-mediated dilation (FMD). Although it is known that NO-dependent endothelial dysfunction occurs after consuming a high-fat meal, the magnitude of the effect and the factors that affect the response are unquantified.

OBJECTIVES

We conducted a systematic review and meta-analysis exploring the quantitative effects of a single high-fat meal on endothelial function and determined the factors that modify the FMD response.

METHODS

Six databases were systematically searched for original research published up to January 2022. Eligible studies measured fasting and postprandial FMD following consumption of a high-fat meal. Meta-regression was used to analyze the effect of moderator variables.

RESULTS

There were 131 studies included, of which 90 were suitable for quantitative meta-analysis. A high-fat meal challenge transiently caused endothelial dysfunction, decreasing postprandial FMD at 2 hours [-1.02 percentage points (pp); 95% CI: -1.34 to -0.70 pp; P < 0.01; I2 = 93.3%], 3 hours [-1.04 pp; 95% CI: -1.48 to -0.59 pp; P < 0.001; I2 = 84.5%], and 4 hours [-1.19 pp; 95% CI: -1.53 to -0.84 pp; P < 0.01; I2 = 94.6%]. Younger, healthy-weight participants exhibited a greater postprandial reduction in the FMD percentage change than older, heavier, at-risk groups after a high-fat meal ( P < 0.05). The percentage of fat in the meals was inversely associated with the magnitude of postprandial changes in FMD at 3 hours (P < 0.01).

CONCLUSIONS

A single, high-fat meal adversely impacts endothelial function, with the magnitude of the impact on postprandial FMD moderated by the fasting FMD, participant age, BMI, and fat content of the meal. Recommendations are made to standardize the design of future postprandial FMD studies and optimize interpretation of results, as high-fat meals are commonly used in clinical studies as a challenge to assess endothelial function and therapeutics. This trial was registered at PROSPERO as CRD42020187244.

Angiopoietin-Like Protein Responses to Pecan-Enriched Diets Versus a Nut-Excluded Diet

Daily pecan consumption improves fasting and postprandial triglycerides, but its effect on angiopoietin-like proteins (ANGPTLs) is unknown. The objective of this study was to investigate the impact of daily pecan consumption for 8 weeks on fasting and postprandial ANGPTL3, -8, and -4. This was an 8-week, randomized, controlled trial with three treatments: two pecan groups and a nut-free control group (n = 16). The ADD group (n = 15) consumed pecans (68 g) as part of a free-living diet, and the SUB group (n = 16) substituted the pecans (68 g) for isocaloric foods from their habitual diet. Fifty-six participants were randomized but nine subjects did not begin or finish the 8-week intervention and/or testing visits. At pre- and post-intervention, a high saturated fat meal was consumed with 3.5 h postprandial blood draws to determine changes in ANGPTL3, -8, and -4. There was a significant suppression in postprandial ANGPTL3 from pre- to post-intervention within ADD and SUB (P = .004 and P = .002, respectively) but not control (ns). There were no other changes within or between groups for fasting and postprandial outcomes. Daily pecan consumption improved postprandial ANGPTL3, which may mediate improvements in lipid metabolism.

Controversies in the Use of Omega-3 Fatty Acids to Prevent Atherosclerosis

PURPOSE OF REVIEW

We discuss current controversies in the clinical use of omega-3 fatty acids (FA), primarily eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and examine discrepancies between recent trials. Furthermore, we discuss potential side effects reported in these studies and the role of mixed omega-3 FA dietary supplements and concerns about their use.

RECENT FINDINGS

REDUCE-IT showed that addition of icosapent ethyl, a highly purified form of EPA, can reduce risk of cardiovascular events among statin-treated individuals with high triglycerides. Additional supportive evidence for EPA has come from other trials and meta-analyses of omega-3 FA therapy. In contrast, trials of mixed EPA/DHA products have consistently failed to improve cardiovascular outcomes. Discrepancies in results reported in RCTs could be explained by differences in omega-3 FA products, dosing, study populations, and study designs including the placebo control formulation. Evidence obtained from highly purified forms should not be extrapolated to other mixed formulations, including "over-the-counter" omega-3 supplements. Targeting TG-rich lipoproteins represents a new frontier for mitigating ASCVD risk. Clinical and basic research evidence suggests that the use of omega-3 FA, specifically EPA, appears to slow atherosclerosis by reducing triglyceride-rich lipoproteins and/or inflammation, therefore addressing residual risk of clinical ASCVD.

The Association of Postprandial Triglyceride Variability with Renal Dysfunction and Microalbuminuria in Patients with Type 2 Diabetic Mellitus: A Retrospective and Observational Study

OBJECTIVE

We examined whether or not day-to-day variations in lipid profiles, especially triglyceride (TG) variability, were associated with the exacerbation of diabetic kidney disease.

METHODS

We conducted a retrospective and observational study. First, 527 patients with type 2 diabetes mellitus (DM) who had had their estimated glomerular filtration rate (eGFR) checked every 6 months since 2012 for over 5 years were registered. Variability in postprandial TG was determined using the standard deviation (SD), SD adjusted (Adj-SD) for the number of measurements, and maximum minus minimum difference (MMD) during the first three years of follow-up. The endpoint was a ≥40% decline from baseline in the eGFR, initiation of dialysis or death. Next, 181 patients who had no micro- or macroalbuminuria in February 2013 were selected from among the 527 patients for an analysis. The endpoint was the incidence of microalbuminuria, initiation of dialysis, or death.

RESULTS

Among the 527 participants, 110 reached a ≥40% decline from baseline in the eGFR or death. The renal survival was lower in the higher-SD, higher-Adj-SD, and higher-MMD groups than in the lower-SD, lower-Adj-SD, and lower-MMD groups, respectively (log-rank test p = 0.0073, 0.0059, and 0.0195, respectively). A lower SD, lower Adj-SD, and lower MMD were significantly associated with the renal survival in the adjusted model (hazard ratio, 1.62, 1.66, 1.59; 95% confidence intervals, 1.05-2.53, 1.08-2.58, 1.04-2.47, respectively). Next, among 181 participants, 108 developed microalbuminuria or death. The nonincidence of microalbuminuria was lower in the higher-SD, higher-Adj-SD, and higher-MMD groups than in the lower-SD, lower-Adj-SD, and lower-MMD groups, respectively (log-rank test p = 0.0241, 0.0352, and 0.0474, respectively).

CONCLUSIONS

Postprandial TG variability is a novel risk factor for eGFR decline and the incidence of microalbuminuria in patients with type 2 DM.

Mechanisms of Atherosclerosis Induced by Postprandial Lipemia

Postprandial lipemia plays an important role in the formation, occurrence, and development of atherosclerosis, and it is closely related to coronary heart disease and other diseases involving endothelial dysfunction, oxidative stress, inflammation, and other mechanisms. Therefore, it has become a focus area for further research. The studies on postprandial lipemia mainly include TG, TRL, VLDL, CM, and remnant cholesterol. Diurnal triglyceride patterns and postprandial hyperlipidemia are very relevant and are now insufficiently covered. The possible mechanisms between postprandial lipemia and cardiovascular disease have been reviewed in this article by referring to relevant literature in recent years. The research progress on the effects of postprandial lipemia on endothelial function, oxidative stress, and inflammation is highlighted. The intervention of postprandial lipemia is discussed. Non-medicinal intervention such as diet and exercise improves postprandial lipemia. As medicinal intervention, statin, fibrate, ezetimibe, omega-3 fatty acids, and niacin have been found to improve postprandial lipid levels. Novel medications such as pemafibrate, PCSK9, and apoCIII inhibitors have been the focus of research in recent years. Gut microbiota is closely related to lipid metabolism, and some studies have indicated that intestinal microorganisms may affect lipid metabolism as environmental factors. Whether intervention of gut microbiota can reduce postprandial lipemia, and therefore against AS, may be worthy of further study.

Hypertriglyceridemia: new approaches in management and treatment

PURPOSE OF REVIEW

Hypertriglyceridemia (HTG), a form of dyslipidemia characterized by elevated plasma of triglycerides (TG), is associated with an increased risk for acute pancreatitis. Moreover, HTG has recently been shown to be linked to the development of atherosclerotic cardiovascular disease (ASCVD); therefore, there is a great interest in better understanding the pathophysiology of HTG and improving its clinical management. In this review, we briefly describe TG metabolism, recent guidelines for the clinical management of HTG and provide an overview of the current and potential new therapies for HTG.

RECENT FINDINGS

Screening patients for HTG is valuable for not only identifying patients with extreme TG elevations, who are at risk for pancreatitis, but also for managing ASCVD risk in patients with more moderate forms of HTG. Therefore, the most recent USA guidelines for cardiovascular diseases recommend using TG as a risk enhancer test, leading to a more aggressive treatment of patients with intermediate risk. Currently, there are several available approaches for reducing plasma TG, which include lifestyle changes, fibrates and omega-3 fatty acid treatment. The addition of eicosapentaenoic acid (EPA) on top of statins has recently been shown to significantly reduce ASCVD events. Nevertheless, there is an unmet need for more effective treatment options. Several new therapies based on newly identified targets in TG metabolism, such as apolipoprotein C-III and angiopoietin-like 3 protein, are currently under development.

SUMMARY

The clinical management of HTG is important in the prevention and treatment of acute pancreatitis and also impacts on how ASCVD risk is managed. More work needs to be done to establish the mechanism for the ability of how EPA lowers ASCVD and how to best integrate it with other lipid-lowering therapies. The efficacy and safety of the novel therapies for HTG should be established soon in the ongoing late-stage clinical trials.

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.

Combination therapy with pemafibrate (K-877) and pitavastatin improves vascular endothelial dysfunction in dahl/salt-sensitive rats fed a high-salt and high-fat diet

Background

Statins suppress the progression of atherosclerosis by reducing low-density lipoprotein (LDL) cholesterol levels. Pemafibrate (K-877), a novel selective peroxisome proliferator-activated receptor α modulator, is expected to reduce residual risk factors including high triglycerides (TGs) and low high-density lipoprotein (HDL) cholesterol during statin treatment. However, it is not known if statin therapy with add-on pemafibrate improves the progression of atherosclerosis. The aim of this study was to assess the effect of combination therapy with pitavastatin and pemafibrate on lipid profiles and endothelial dysfunction in hypertension and insulin resistance model rats.

Methods

Seven-week-old male Dahl salt-sensitive (DS) rats were divided into the following five treatment groups (normal diet (ND) plus vehicle, high-salt and high-fat diet (HD) plus vehicle, HD plus pitavastatin (0.3 mg/kg/day), HD plus pemafibrate (K-877) (0.5 mg/kg/day), and HD plus combination of pitavastatin and pemafibrate) and treated for 12 weeks. At 19 weeks, endothelium-dependent relaxation of the thoracic aorta in response to acetylcholine was evaluated.

Results

After feeding for 12 weeks, systolic blood pressure and plasma levels of total cholesterol were significantly higher in the HD-vehicle group compared with the ND-vehicle group. Combination therapy with pitavastatin and pemafibrate significantly reduced systolic blood pressure, TG levels, including total, chylomicron (CM), very LDL (VLDL), HDL-TG, and cholesterol levels, including total, CM, VLDL, and LDL-cholesterol, compared with vehicle treatment. Acetylcholine caused concentration-dependent relaxation of thoracic aorta rings that were pre-contracted with phenylephrine in all rats. Relaxation rates in the HD-vehicle group were significantly lower compared with the ND-vehicle group. Relaxation rates in the HD-combination of pitavastatin and pemafibrate group significantly increased compared with the HD-vehicle group, although neither medication alone ameliorated relaxation rates significantly. Western blotting experiments showed increased phosphorylated endothelial nitric oxide synthase protein expression in aortas from rats in the HD-pemafibrate group and the HD-combination group compared with the HD-vehicle group. However, the expression levels did not respond significantly to pitavastatin alone.

Conclusions

Combination therapy with pitavastatin and pemafibrate improved lipid profiles and endothelial dysfunction in hypertension and insulin resistance model rats. Pemafibrate as an add-on strategy to statins may be useful for preventing atherosclerosis progression.

Postprandial lipaemia following consumption of a meal enriched with medium chain saturated and/or long chain omega-3 polyunsaturated fatty acids. A randomised cross-over study

BACKGROUND & AIMS

Postprandial lipaemic response has emerged as a risk factor for cardiovascular disease. Dietary fats such as medium-chain saturated fatty acids (MCSFA) and long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) are known to reduce postprandial lipaemic responses. The combination of the two could potentially have complementary and/or synergistic effects for optimising cardiovascular health. This study aims to investigate the effects of MCSFA (coconut oil) with or without LCn-3PUFA (fish oil) inclusion in the test meal on postprandial blood lipids in healthy adults.

METHODS

In a randomised, double-blinded, placebo-controlled, 2 × 2 factorial cross-over study, participants (n = 15) were randomised to receive four standardised isocaloric test meals. Test meals include: placebo [PL, containing no fish oil (0 g EPA & DHA) or coconut oil (0 g MCSFA)], fish oil [FO, 6 g fish oil (3.85 g EPA & DHA), containing no coconut oil (0 g MCSFA)], coconut oil [CO, 18.65 g coconut oil (15 g MCSFA), containing no fish oil (0 g EPA & DHA)] and coconut oil + fish oil [COFO, 18.65 g coconut oil (15 g MCSFA) + 6 g fish oil (3.85 g EPA & DHA)]; all providing a total fat content of 33.5 g. Participants received all four treatments on four separate test days with at least 3 days washout in between. Blood parameters were measured by finger pricks at 7 timepoints between 0 and 300min. The primary outcome of this study was the change in postprandial triglycerides (TG) concentrations with secondary outcomes as total cholesterol, high-density lipoprotein cholesterol and blood glucose concentrations.

RESULTS

TG area under the curve (AUC) (mmol/L/min) was significantly lower for FO (383.67, p = 0.0125) and COFO (299.12, p = 0.0186) in comparison to PL (409.17) only. TG incremental area under the curve (iAUC) (mmol/L/min) was significantly lower with COFO (59.67) in comparison to CO (99.86), (p = 0.0480). Compared to PL, the change in absolute TG concentrations (mmol/L) from baseline to post TG peak time (180min) after FO were significantly less at 240min (0.39 vs 0.15), 270min (0.2 vs 0.1), and 300min (0.28 vs 0.06), and after COFO was significantly less at 300min (0.28 vs 0.16) (p < 0.05). No significant differences in postprandial AUC and iAUC for any other blood parameters were reported.

CONCLUSIONS

Our study demonstrated that LCn-3PUFA with or without MCSFA but not MCSFA alone are effective in reducing postprandial TG in healthy individuals.

The Metabolic Concept of Meal Sequence vs. Satiety: Glycemic and Oxidative Responses with Reference to Inflammation Risk, Protective Principles and Mediterranean Diet

With increasing exposure to eating opportunities and postprandial conditions becoming dominant states, acute effects of meals are garnering interest. In this narrative review, meal components, combinations and course sequence were questioned vis-à-vis resultant postprandial responses, including satiety, glycemic, oxidative and inflammatory risks/outcomes vs. protective principles, with reference to the Mediterranean diet. Representative scientific literature was reviewed and explained, and corresponding recommendations discussed and illustrated. Starting meals with foods, courses and/or preloads high in innate/added/incorporated water and/or fibre, followed by protein-based courses, delaying carbohydrates and fatty foods and minimizing highly-processed/sweetened hedonic foods, would increase satiety-per-calorie vs. obesogenic passive overconsumption. Similarly, starting with high-water/fibre dishes, followed by high-protein foods, oils/fats, and delayed/reduced slowly-digested whole/complex carbohydrate sources, optionally closing with simpler carbohydrates/sugars, would reduce glycaemic response. Likewise, starting with foods high in innate/added/incorporated water/fibre/antioxidants, high monounsaturated fatty acid foods/oils, light proteins and whole/complex carbohydrate foods, with foods/oils low in n-6 polyunsaturated fatty acids (PUFA) and n-6:n-3 PUFA ratios, and minimal-to-no red meat and highly/ultra-processed foods/lipids, would reduce oxidative/inflammatory response. Pyramids illustrating representative meal sequences, from most-to-least protective foods, visually communicate similarities between axes, suggesting potential unification for optimal meal sequence, consistent with anti-inflammatory nutrition and Mediterranean diet/meal principles, warranting application and outcome evaluation.

Triglycerides and endothelial function: molecular biology to clinical perspective

PURPOSE OF REVIEW

Recently, a high level of triglycerides has attracted much attention as an important residual risk factor of cardiovascular events. We will review and show the mechanisms underlying the association of endothelial dysfunction with hypertriglyceridemia and present clinical evidence for a relationship between endothelial function and triglycerides.

RECENT FINDINGS

Clinical studies have shown that hypertriglyceridemia is associated with endothelial dysfunction. It is likely that hypertriglyceridemia impairs endothelial function through direct and indirect mechanisms. Therefore, hypertriglyceridemia is recognized as a therapeutic target in the treatment of endothelial dysfunction. Although experimental and clinical studies have shown that fibrates and omega-3 fatty acids not only decrease triglycerides but also improve endothelial function, the effects of these therapies on cardiovascular events are controversial.

SUMMARY

Accumulating evidence suggests that hypertriglyceridemia is an independent risk factor for endothelial dysfunction. Triglycerides should be considered more seriously as a future target to reduce cardiovascular events. Results of ongoing studies may show the benefit of lowering triglycerides and provide new standards of care for patients with hypertriglyceridemia possibly through improvement in endothelial function.

Modulation of endothelial cell responses and vascular function by dietary fatty acids

Healthy and functional endothelial cells play important roles in maintaining vascular homeostasis, whereas endothelial dysfunction initiates and exacerbates vascular disease progression. Interventional studies with dietary fatty acids have shown that these molecules have varying effects on vascular function. It is hypothesized that the actions of dietary fatty acids on vascular function may be mediated in part through endothelial cells. This review summarizes the results of studies that have examined the acute and chronic effects of dietary fatty acids on endothelial function and vascular properties in humans, as well as the potential mechanisms by which n-3 polyunsaturated fatty acids regulate endothelial function. Altogether, this article provides an extensive review of how fatty acids contribute to vascular function through their ability to modulate endothelial cells and discusses relationships between dietary fatty acids and endothelial cells in the context of vascular dysfunction.

The Physiological Effect of n-3 Polyunsaturated Fatty Acids (n-3 PUFAs) Intake and Exercise on Hemorheology, Microvascular Function, and Physical Performance in Health and Cardiovascular Diseases; Is There an Interaction of Exercise and Dietary n-3 PUFA Intake?

Physical activity has a beneficial effect on systemic hemodynamics, physical strength, and cardiac function in cardiovascular (CV) patients. Potential beneficial effects of dietary intake of n-3 polyunsaturated fatty acids (n-3 PUFAs), such as α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid on hemorheology, vascular function, inflammation and potential to improve physical performance as well as other CV parameters are currently investigated. Recent meta-analysis suggests no effect of n-3 PUFA supplementation on CV function and outcomes of CV diseases. On the other hand, some studies support beneficial effects of n-3 PUFAs dietary intake on CV and muscular system, as well as on immune responses in healthy and in CV patients. Furthermore, the interaction of exercise and dietary n-3 PUFA intake is understudied. Supplementation of n-3 PUFAs has been shown to have antithrombotic effects (by decreasing blood viscosity, decreasing coagulation factor and PAI-1 levels and platelet aggregation/reactivity, enhancing fibrinolysis, but without effects on erythrocyte deformability). They decrease inflammation by decreasing IL-6, MCP-1, TNFα and hsCRP levels, expression of endothelial cell adhesion molecules and significantly affect blood composition of fatty acids. Treatment with n-3 PUFAs enhances brachial artery blood flow and conductance during exercise and enhances microvascular post-occlusive hyperemic response in healthy humans, however, the effects are unknown in cardiovascular patients. Supplementation of n-3 PUFAs may improve anaerobic endurance and may modulate oxygen consumption during intense exercise, may increase metabolic capacity, enhance endurance capacity delaying the onset of fatigue, and improving muscle hypertrophy and neuromuscular function in humans and animal models. In addition, n-3 PUFAs have anti-inflammatory and anti-nociceptive effects and may attenuate delayed-onset muscle soreness and muscle stiffness, and preserve joint mobility. On the other hand, effects of n-3 PUFAs were variably observed in men and women and they vary depending on dietary protocol, type of supplementation and type of sports activity undertaken, both in healthy and cardiovascular patients. In this review we will discuss the physiological effects of n-3 PUFA intake and exercise on hemorheology, microvascular function, immunomodulation and inflammation and physical performance in healthy persons and in cardiovascular diseases; elucidating if there is an interaction of exercise and diet.

Effect of Nutrient and Micronutrient Intake on Chylomicron Production and Postprandial Lipemia

Postprandial lipemia, which is one of the main characteristics of the atherogenic dyslipidemia with fasting plasma hypertriglyceridemia, low high-density lipoprotein cholesterol and an increase of small and dense low-density lipoproteins is now considered a causal risk factor for atherosclerotic cardiovascular disease and all-cause mortality. Postprandial lipemia, which is mainly related to the increase in chylomicron production, is frequently elevated in individuals at high cardiovascular risk such as obese or overweight patients, type 2 diabetic patients and subjects with a metabolic syndrome who share an insulin resistant state. It is now well known that chylomicron production and thus postprandial lipemia is highly regulated by many factors such as endogenous factors: circulating factors such as hormones or free fatty acids, genetic variants, circadian rhythms, or exogenous factors: food components, dietary supplements and prescription drugs. In this review, we focused on the effect of nutrients, micronutrients and phytochemicals but also on food structure on chylomicron production and postprandial lipemia.

The Role of n-3 Fatty Acids in Cardiovascular Disease: Back to the Future

Cardiovascular disease (CVD) remains the major cause of death and disability worldwide, and residual risk after implementing all current therapies is still high. In this context, the latest (2016) European Cardiology Society/European Atherosclerosis Society guidelines recommend that triglyceride (TG)-lowering drugs should be used in high-risk patients with TGs levels >2.3 mmol/L (200 mg/dL), after lifestyle measures fail to lower them. After several neutral CVD outcome trials with n-3 fatty acids, the Reduction of Cardiovascular Events with EPA–Intervention Trial met its primary end point, that is, among patients with elevated TGs levels despite the use of statins, the risk of ischemic events, including cardiovascular death, was significantly lower in those who received 4 g of icosapent ethyl daily. In this review, we comment on the findings of previous and recently published randomized controlled CVD outcome trials assessing n-3 fatty acids supplementation. Both efficacy and safety, as well as future perspectives, are discussed.

Nutritional and Nutraceutical Composition of Pansies (Viola × wittrockiana) During Flowering

Edible flowers consumption and use are an increasing food trend worldwide, although information concerning their nutritional composition and nutraceutical value is still scarce. Thus, the aim of this study was to contribute to the popularization of pansies (Viola × wittrockiana), through the analysis of the nutritional and nutraceutical features of pansies with different colors (white, yellow, and red) and flowering stages. Both flower type and flowering stage influenced the flower composition. When completely open, white and yellow pansies had the highest contents of protein (>2.00 g/100 g fresh weight), while red pansies had the highest content of carbohydrates (8.0 g/100 g fresh weight). Regarding the fatty acid profiles, linoleic acid was always predominant (ranging between 18.7 and 51.0 g/100 g fatty acids), followed by the palmitic and linolenic acids. During flowering, there was an increase in protein, fat, and linolenic acid contents in white and yellow pansies, whereas in red pansies the values did not change. Red pansies were characterized by the highest contents of total carotenoids (873 to 1300 µg β-carotene/g dry weight) and monomeric anthocyanins (303 to 402 µg Cy-3 glu/g dry weight); however, white and yellow pansies showed an increase in the values of total reducing capacity (total phenols), hydrolysable tannins, flavonoids, monomeric anthocyanins, and antioxidant activity from the bud to completely open flower stage. Our results underline the nutritional differences between pansies with different colors at distinct stages of development and their potential health benefits, suggesting that they can be used as ingredient to improve the nutritional properties of foods. PRACTICAL APPLICATION: The market of edible flowers is increasing, although little information in nutritional view is available. So, the present study was conducted to contribute to the popularization of edible flowers as a new and prospective source for the food industry, as well as a promising product for human nutrition. The results of the present study underline the nutritional differences between pansies with different colors at distinct stages of development and their potential health benefits, suggesting that they can be used as ingredient to improve the nutritional properties of foods.

Omega-3 polyunsaturated fatty acids-enriched hen eggs consumption enhances microvascular reactivity in young healthy individuals

The beneficial effect of omega-3 polyunsaturated fatty acids (PUFA) supplementation on the cardiovascular (CV) system is well supported in CV patients; however, the effect of the consumption of omega-3 PUFA-enriched functional food in healthy individuals is still not fully elucidated. This study aimed to determine the effect of the consumption of omega-3 PUFA-enriched hen eggs on the microvascular reactivity (primary outcome), blood pressure (BP), and serum lipid profile in young healthy individuals. The control group (N = 16) ate 3 ordinary hen eggs (277 mg of omega-3 PUFAs/day), and the OMEGA-3 group (N = 20) ate 3 omega-3 PUFA-enriched eggs containing 259 mg of omega-3 PUFAs/egg daily (α-linolenic acid (ALA), 167 mg/egg; eicosapentaenoic acid (EPA), 7 mg/egg; docosahexaenoic acid (DHA), 84 mg/egg) for 3 weeks (777 mg of omega-3 PUFA/day). Postocclusive reactive hyperemia (PORH) in skin microcirculation assessed by laser Doppler flowmetry, serum lipid profile, fasting blood glucose, high-sensitivity C-reactive protein (hsCRP), and arterial BP were measured in all subjects before and after the protocol. PORH was significantly enhanced, and triglycerides, hsCRP, and BP were significantly decreased in the OMEGA-3 group compared with baseline measurements, whereas there was no significant difference in the control group after the protocol when compared with baseline. To the best of our knowledge, this is the first study to demonstrate that consumption of a mixture of omega-3 PUFA (ALA + EPA + DHA), provided via enriched hen eggs, elicits changes in the microvascular reactivity, BP, and triglyceride level in healthy subjects that are associated with CV benefits, thus suggesting that daily consumption of omega-3 PUFA-enriched eggs in healthy individuals may potentially contribute to CV risk factor attenuation and disease prevention.

Hypertriglyceridemia and omega-3 fatty acids: Their often overlooked role in cardiovascular disease prevention

AIMS

This review aims to describe the pathogenic role of triglycerides in cardiometabolic risk, and the potential role of omega-3 fatty acids in the management of hypertriglyceridemia and cardiovascular disease.

DATA SYNTHESIS

In epidemiological studies, hypertriglyceridemia correlates with an increased risk of cardiovascular disease, even after adjustment for low density lipoprotein cholesterol (LDL-C) levels. This has been further supported by Mendelian randomization studies where triglyceride-raising common single nucleotide polymorphisms confer an increased risk of developing cardiovascular disease. Although guidelines vary in their definition of hypertriglyceridemia, they consistently define a normal triglyceride level as <150 mg/dL (or <1.7 mmol/L). For patients with moderately elevated triglyceride levels, LDL-C remains the primary target for treatment in both European and US guidelines. However, since any triglyceride level in excess of normal increases the risk of cardiovascular disease, even in patients with optimally managed LDL-C levels, triglycerides are an important secondary target in both assessment and treatment. Dietary changes are a key element of first-line lifestyle intervention, but pharmacological treatment including omega-3 fatty acids may be indicated in people with persistently high triglyceride levels. Moreover, in patients with pre-existing cardiovascular disease, omega-3 supplements significantly reduce the risk of sudden death, cardiac death and myocardial infarction and are generally well tolerated.

CONCLUSIONS

Targeting resistant hypertriglyceridemia should be considered as a part of clinical management of cardiovascular risk. Omega-3 fatty acids may represent a valuable resource to this aim.

Postprandial lipemia: factoring in lipemic response for ranking foods for their healthiness

One of the limitations for ranking foods and meals for healthiness on the basis of the glycaemic index (GI) is that the GI is subject to manipulation by addition of fat. Postprandial lipemia, defined as a rise in circulating triglyceride containing lipoproteins following consumption of a meal, has been recognised as a risk factor for the development of cardiovascular disease and other chronic diseases. Many non-modifiable factors (pathological conditions, genetic background, age, sex and menopausal status) and life-style factors (physical activity, smoking, alcohol and medication use, dietary choices) may modulate postprandial lipemia. The structure and the composition of a food or a meal consumed also plays an important role in the rate of postprandial appearance and clearance of triglycerides in the blood. However, a major difficulty in grading foods, meals and diets according to their potential to elevate postprandial triglyceride levels has been the lack of a standardised marker that takes into consideration both the general characteristics of the food and the food’s fat composition and quantity. The release rate of lipids from the food matrix during digestion also has an important role in determining the postprandial lipemic effects of a food product. This article reviews the factors that have been shown to influence postprandial lipemia with a view to develop a novel index for ranking foods according to their healthiness. This index should take into consideration not only the glycaemic but also lipemic responses.

Enriching Diet with n-3 PUFAs to Help Prevent Cardiovascular Diseases in Healthy Adults: Results from Clinical Trials

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are believed to be important for cardiovascular health. Many investigations have been carried out in an attempt to examine the effect of n-3 PUFAs intake, in the form of supplementation or fortified foods, for the management of cardiovascular disease (CVD) and risk factors for CVD, whereas less is known about the effect on healthy individuals. The present study reviews the available literature in order to examine the relationship between n-3 PUFAs intake, either via supplementation or enriched food, and the prevention of CVD among healthy adults. Interventional clinical trials on subjects aged >18 years old with none of the established risk factors for CVD have been considered for review. n-3 PUFAs supplementation or enriched food may positively regulate triglycerides and some lipoprotein subsets, as well as several vascular and coagulation parameters, even in healthy patients, presenting no risk factors for CVD, suggesting a protective effect. Diet enrichment with omega-3 is likely to be useful in helping to lower the risk of developing CVD in healthy individuals, but still offers no strong evidence of a tangible benefit on a population level. Additional studies are needed to determine the optimal daily intake, especially to prevent the unfavorable effects of PUFAs over-consumption.

The effects of vitamin D and omega-3 fatty acid co-supplementation on glycemic control and lipid concentrations in patients with gestational diabetes

OBJECTIVE

This study was performed to evaluate the effects of vitamin D and omega-3 fatty acids co-supplementation on glucose metabolism and lipid concentrations in gestational diabetes (GDM) patients.

METHODS

This randomized double-blind placebo-controlled clinical trial was done among 140 GDM patients. Participants were randomly divided into 4 groups to receive: (1) 1000 mg omega-3 fatty acids containing 360 mg eicosapentaenoic acid and 240 mg docosahexaenoic acid (DHA) twice a day + vitamin D placebo (n = 35); (2) 50,000 IU vitamin D every 2 weeks + omega-3 fatty acids placebo (n = 35); (3) 50,000 IU vitamin D every 2 weeks + 1000 mg omega-3 fatty acids twice a day (n = 35), and (4) vitamin D placebo + omega-3 fatty acids placebo (n = 35) for 6 weeks.

RESULTS

After 6 weeks of intervention, patients who received combined vitamin D and omega-3 fatty acids supplements compared with vitamin D, omega-3 fatty acids, and placebo had significantly decreased fasting plasma glucose (-7.3 ± 7.8, -6.9 ± 6.6, -4.0 ± 2.5, and +1.0 ± 11.4 mg/dL, respectively, P < .001), serum insulin levels (-1.9 ± 1.9, -1.3 ± 6.3, -0.4 ± 6.3, and +2.6 ± 6.5 μIU/mL, respectively, P = .005), homeostatic model of assessment for insulin resistance (-0.7 ± 0.6, -0.5 ± 1.4, -0.2 ± 1.5, and +0.6 ± 1.5, respectively, P < .001) and increased quantitative insulin sensitivity check index (+0.01 ± 0.01, +0.008 ± 0.02, +0.002 ± 0.02, and -0.005 ± 0.02, respectively, P = .001). In addition, changes in serum triglycerides (-8.2 ± 41.0, +7.6 ± 31.5, +3.6 ± 29.9, and +20.1 ± 29.6 mg/dL, respectively, P = .006) and very low-density lipoprotein cholesterol (-1.6 ± 8.2, +1.5 ± 6.3, +0.8 ± 6.0, and +4.0 ± 5.9 mg/dL, respectively, P = .006) in the vitamin D plus omega-3 fatty acids group were significantly different from the changes in these indicators in the vitamin D, omega-3 fatty acids, and placebo groups.

CONCLUSION

Overall, vitamin D and omega-3 fatty acids co-supplementation for 6 weeks among GDM patients had beneficial effects on fasting plasma glucose, serum insulin levels, homeostatic model of assessment for insulin resistance, quantitative insulin sensitivity check index, serum triglycerides, and very low-density lipoprotein cholesterol levels.

The effects of omega-3 fatty acids and vitamin E co-supplementation on gene expression of lipoprotein(a) and oxidized low-density lipoprotein, lipid profiles and biomarkers of oxidative stress in patients with polycystic ovary syndrome

This study was conducted to determine the effects of omega-3 fatty acids and vitamin E co-supplementation on gene expression of lipoprotein(a) (Lp[a]) and oxidized low-density lipoprotein (Ox-LDL), lipid profiles and biomarkers of oxidative stress in women with polycystic ovary syndrome (PCOS). This randomized double-blind, placebo-controlled trial was done on 68 women diagnosed with PCOS according to the Rotterdam criteria aged 18-40 years old. Participants were randomly assigned into two groups to receive either 1000 mg omega-3 fatty acids from flaxseed oil containing 400 mg α-Linolenic acid plus 400 IU vitamin E supplements (n = 34) or placebo (n = 34) for 12 weeks. Lp(a) and Ox-LDL mRNA levels were quantified in peripheral blood mononuclear cells of PCOS women with RT-PCR method. Lipid profiles and biomarkers of oxidative stress were quantified at the beginning of the study and after 12-week intervention. Quantitative results of RT-PCR demonstrated that compared with the placebo, omega-3 fatty acids and vitamin E co-supplementation downregulated expressed levels of Lp(a) mRNA (P < 0.001) and Ox-LDL mRNA (P < 0.001) in peripheral blood mononuclear cells of women with PCOS. In addition, compared to the placebo group, omega-3 fatty acids and vitamin E co-supplementation resulted in a significant decrease in serum triglycerides (-22.1 ± 22.3 vs. +7.7 ± 23.6 mg/dL, P < 0.001), VLDL- (-4.4 ± 4.5 vs. +1.5 ± 4.7 mg/dL, P < 0.001), total- (-20.3 ± 16.6 vs. +12.2 ± 26.1 mg/dL, P < 0.001), LDL- (-16.7 ± 15.3 vs. +11.9 ± 26.1 mg/dL, P < 0.001) and total-/HDL-cholesterol (-0.5 ± 0.6 vs. +0.4 ± 0.8, P < 0.001). There were a significant increase in plasma total antioxidant capacity (+89.4 ± 108.9 vs. +5.9 ± 116.2 mmol/L, P = 0.003) and a significant decrease in malondialdehyde levels (-0.3 ± 0.4 vs. -0.008 ± 0.6 μmol/L, P = 0.01) by combined omega-3 fatty acids and vitamin E intake compared with the placebo group. Overall, omega-3 fatty acids and vitamin E co-supplementation for 12 weeks in PCOS women significantly improved gene expression of Lp(a) and Ox-LDL, lipid profiles and biomarkers of oxidative stress.

Early initiation of eicosapentaenoic acid and statin treatment is associated with better clinical outcomes than statin alone in patients with acute coronary syndromes: 1-year outcomes of a randomized controlled study

BACKGROUND

Early initiation of EPA treatment in combination with a statin within 24h after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (MI) reduces inflammation and ventricular arrhythmia compared with statin monotherapy; however, the impact of early initiation of EPA treatment on cardiovascular events is unclear. We determined whether early eicosapentaenoic acid (EPA) treatment in patients with acute coronary syndrome (ACS) reduces adverse cardiovascular events.

METHODS

This prospective, open-label, blind end point-randomized trial consisted of 241 patients with ACS. Patients were randomly assigned to receive pitavastatin (2mg/day) with or without 1800mg/day of EPA initiated within 24h after PCI. The primary endpoint was defined as cardiovascular events occurring within 1year, including death from a cardiovascular cause, nonfatal stroke, nonfatal MI and revascularization.

RESULTS

The mean EPA/arachidonic acid ratio at follow-up was 0.40 in the control group and 1.15 in the EPA group. A primary endpoint event occurred in 11 patients (9.2%) in the EPA group and 24 patients (20.2%) in the control group (absolute risk reduction, 11.0%; hazard ratio, 0.42; 95% confidence interval, 0.21 to 0.87; P=0.02). Notably, death from a cardiovascular cause at 1year was significantly lower in the EPA group than in the control group (0.8% vs. 4.2%, P=0.04).

CONCLUSIONS

Early initiation of treatment with EPA combined with statin after successful primary PCI reduced cardiovascular events after ACS.

CLINICAL TRIAL REGISTRATION

UMIN Clinical Trials Registry (UMIN-CTR); Registry Number, UMIN000016723; URL, http://www.umin.ac.jp/ctr/index-j.htm.

Postprandial Hyperlipidemia and Remnant Lipoproteins

Fasting hypertriglyceridemia is positively associated with the morbidity of coronary heart disease (CHD), and postprandial (non-fasting) hypertriglyceridemia is also correlated with the risk status for CHD, which is related to the increase in chylomicron (CM) remnant lipoproteins produced from the intestine. CM remnant particles, as well as oxidized low density lipoprotein (LDL) or very low density lipoprotein (VLDL) remnants, are highly atherogenic and act by enhancing systemic inflammation, platelet activation, coagulation, thrombus formation, and macrophage foam cell formation. The cholesterol levels of remnant lipoproteins significantly correlate with small, dense LDL; impaired glucose tolerance (IGT) and CHD prevalence. We have developed an assay of apolipoprotein (apo)B-48 levels to evaluate the accumulation of CM remnants. Fasting apoB-48 levels correlate with the morbidity of postprandial hypertriglyceridemia, obesity, type III hyperlipoproteinemia, the metabolic syndrome, hypothyroidism, chronic kidney disease, and IGT. Fasting apoB-48 levels also correlate with carotid intima-media thickening and CHD prevalence, and a high apoB-48 level is a significant predictor of CHD risk, independent of the fasting TG level. Diet interventions, such as dietary fibers, polyphenols, medium-chain fatty acids, diacylglycerol, and long-chain n-3 polyunsaturated fatty acids (PUFA), ameliorate postprandial hypertriglyceridemia, moreover, drugs for dyslipidemia (n-3 PUFA, statins, fibrates or ezetimibe) and diabetes concerning incretins (dipeptidyl-peptidase IV inhibitor or glucagon like peptide-1 analogue) may improve postprandial hypertriglyceridemia. Since the accumulation of CM remnants correlates to impaired lipid and glucose metabolism and atherosclerotic cardiovascular events, further studies are required to investigate the characteristics, physiological activities, and functions of CM remnants for the development of new interventions to reduce atherogenicity.

Bioavailability of n-3 fatty acids from n-3-enriched foods and fish oil with different oxidative quality in healthy human subjects: a randomised single-meal cross-over study

Regular consumption of long-chain n-3 fatty acids (LC n-3 FA) reduces postprandial triacylglycerolaemia. Functional foods and supplements are alternative sources of LC n-3 FA; however, emulsification technologies, food matrices and altered lipid oxidation levels affect their bioavailability. Moreover, which functional foods are optimal LC n-3 FA carriers is unknown. The aim of the study was to determine the bioavailability of LC n-3 FA and the postprandial TAG response after the intake of oxidised or non-oxidised cod liver oil and after the intake of emulsified or non-emulsified LC n-3 FA using novel functional food items as LC n-3 FA carriers in a randomised cross-over acute study. A total of twenty-four healthy subjects completed the study in which subjects consumed one of four different test meals containing 1·5 g LC n-3 FA, or a control meal with no LC n-3 FA. Postprandial TAG-rich lipoproteins were isolated and their fatty acid composition was measured. The LC n-3 FA from emulsified foods were more rapidly incorporated into TAG-rich lipoproteins compared with non-emulsified foods. The incorporation of LC n-3 FA was similar for oils emulsified in yogurt or juice and was unaffected by the oxidative status of the oil. Postprandial TAG levels did not differ among the various test meals. In conclusion, emulsification increases the bioavailability of LC n-3 FA through a more rapid incorporation into TAG-rich lipoproteins, and juice and yogurt are equally suited as LC n-3 FA carriers. The acute intake of oxidised cod liver oil does not influence the incorporation of LC n-3 FA into TAG-rich lipoproteins.

Effects of 6-month eicosapentaenoic acid treatment on postprandial hyperglycemia, hyperlipidemia, insulin secretion ability, and concomitant endothelial dysfunction among newly-diagnosed impaired glucose metabolism patients with coronary artery disease. An open label, single blinded, prospective randomized controlled trial

Background

Recent experimental studies have revealed that n-3 fatty acids, such as eicosapentaenoic acid (EPA) regulate postprandial insulin secretion, and correct postprandial glucose and lipid abnormalities. However, the effects of 6-month EPA treatment on postprandial hyperglycemia and hyperlipidemia, insulin secretion, and concomitant endothelial dysfunction remain unknown in patients with impaired glucose metabolism (IGM) and coronary artery disease (CAD).

Methods and results

We randomized 107 newly diagnosed IGM patients with CAD to receive either 1800 mg/day of EPA (EPA group, n = 53) or no EPA (n = 54). Cookie meal testing (carbohydrates: 75 g, fat: 28.5 g) and endothelial function testing using fasting-state flow-mediated dilatation (FMD) were performed before and after 6 months of treatment. The primary outcome of this study was changes in postprandial glycemic and triglyceridemic control and secondary outcomes were improvement of insulin secretion and endothelial dysfunction. After 6 months, the EPA group exhibited significant improvements in EPA/arachidonic acid, fasting triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C). The EPA group also exhibited significant decreases in the incremental TG peak, area under the curve (AUC) for postprandial TG, incremental glucose peak, AUC for postprandial glucose, and improvements in glycometabolism categorization. No significant changes were observed for hemoglobin A1c and fasting plasma glucose levels. The EPA group exhibited a significant increase in AUC-immune reactive insulin/AUC-plasma glucose ratio (which indicates postprandial insulin secretory ability) and significant improvements in FMD. Multiple regression analysis revealed that decreases in the TG/HDL-C ratio and incremental TG peak were independent predictors of FMD improvement in the EPA group.

Conclusions

EPA corrected postprandial hypertriglyceridemia, hyperglycemia and insulin secretion ability. This amelioration of several metabolic abnormalities was accompanied by recovery of concomitant endothelial dysfunction in newly diagnosed IGM patients with CAD.

Clinical Trial Registration UMIN Registry number: UMIN000011265 (https://www.upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&type=summary&recptno=R000013200&language=E)

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0437-y) contains supplementary material, which is available to authorized users.

Chylomicrons: Advances in biology, pathology, laboratory testing, and therapeutics

The adequate absorption of lipids is essential for all mammalian species due to their inability to synthesize some essential fatty acids and fat-soluble vitamins. Chylomicrons (CMs) are large, triglyceride-rich lipoproteins that are produced in intestinal enterocytes in response to fat ingestion, which function to transport the ingested lipids to different tissues. In addition to the contribution of CMs to postprandial lipemia, their remnants, the degradation products following lipolysis by lipoprotein lipase, are linked to cardiovascular disease. In this review, we will focus on the structure-function and metabolism of CMs. Second, we will analyze the impact of gene defects reported to affect CM metabolism and, also, the role of CMs in other pathologies, such as atherothrombotic cardiovascular disease and diabetes mellitus. Third, we will provide an overview of the laboratory tests currently used to study CM disorders, and, finally, we will highlight current treatments in diseases affecting CMs.

Postprandial hyperlipidemia as a potential residual risk factor

Statin therapy targeting reduction of low-density lipoprotein cholesterol (LDL-C) decreases the risk of coronary heart disease (CHD) and all-cause mortality. However, a substantial number of cases of CHD are not prevented and residual risk factors remain unsettled. A high triglyceride (TG) level is considered to be an important and residual risk factor. Postprandial hyperlipidemia is a condition in which TG-rich chylomicron remnants are increased during the postprandial period and hypertriglycedemia is protracted. Postprandial hyperlipidemia evokes atherogenesis during the postprandial period. Several prospective studies have revealed that nonfasting serum TG levels predict the incidence of CHD. Values of TG, remnant lipoprotein cholesterol, and remnant lipoprotein TG after fat loading were significantly higher in diabetes patients with insulin resistance than in diabetes patients without insulin resistance. Endothelial dysfunction is an initial process of atherogenesis and it contributes to the pathogenesis of CHD. Postprandial hyperlipidemia (postprandial hypertriglyceridemia) is involved in the production of proinflammatory cytokines, recruitment of neutrophils, and generation of oxidative stress, resulting in endothelial dysfunction in healthy subjects, hypertriglyceridemic patients, or type 2 diabetic patients. Effective treatment has not been established till date. Ezetimibe or omega-3 fatty acids significantly decrease postprandial TG elevation and postprandial endothelial dysfunction. Ezetimibe or omega-3 fatty acids added to statin therapy reduce serum TG levels and result in good outcomes in patients with CHD. In conclusion, postprandial hyperlipidemia is an important and residual risk factor especially in patients with insulin resistance syndrome (metabolic syndrome) and diabetes mellitus. Further studies are needed to establish effective treatment.

Prognostic significance of endothelial dysfunction in patients undergoing percutaneous coronary intervention in the era of drug-eluting stents

Background

Endothelial function is a prognostic predictor in patients undergoing percutaneous coronary intervention (PCI). However, in an era with widespread use of drug-eluting stents, the clinical relevance of endothelial dysfunction on restenosis in patients undergoing PCI has not been fully evaluated.

Methods

This study included 80 patients with stable angina pectoris. Flow-mediated dilation (FMD) of the brachial artery was examined 1 week after PCI. Patients were retrospectively followed-up for an average of 21 months after PCI. The primary endpoints included cardiac death, nonfatal myocardial infarction, stroke, coronary revascularization, and critical limb ischemia.

Results

A drug-eluting stent was used in 58 patients and a cardiovascular event was recorded in 34 patients during follow-up. The incidence of all cardiovascular diseases was significantly greater in the low FMD (median FMD <4.2 %) than the high FMD (median FMD ≥4.2 %) group (60 % vs. 25 %, p <0.01). Furthermore, the incidence of coronary revascularization was significantly higher in the low than the high FMD group (p = 0.02), while the incidence of in-stent restenosis did not differ between the two groups. Cox regression analysis showed that low FMD was an independent predictor of cardiovascular events (hazard ratio: 2.77, 95 % confidence interval: 1.23 to 6.19, p = 0.01).

Conclusions

Impaired brachial artery FMD independently predicts long-term cardiovascular events after PCI in the era of drug-eluting stents.

Dysbetalipoproteinemia: an extreme disorder of remnant metabolism

PURPOSE OF REVIEW

Lipoprotein metabolism and the role of apolipoprotein E in the pathogenesis of dysbetalipoproteinemia.

RECENT FINDINGS

Remnant lipoproteins, modulated by lifestyle and genetic factors, are atherogenic. Dysbetalipoproteinemia could be viewed as a monogenic disorder of remnant metabolism.

SUMMARY

Elevated plasma triglyceride and cholesterol concentrations (mixed hyperlipidemias) are commonly encountered and dysbetaliproteinemia should be considered in this setting. Dysbetalipoproteinemia (remnant clearance disease, Fredrickson type III hyperlipidemia) is an uncommon dyslipoproteinemia related to mutations in apolipoprotein E that disrupt the clearance of remnants of triglyceride-rich lipoproteins; it may be overlooked because xanthomata of the skin and/or tendons occur in a minority of patients. The diagnosis ideally requires the demonstration of remnant lipoprotein accumulation and a genetic cause. Genotyping for apolipoprotein E2 may not prove the diagnosis as it may be associated with low plasma lipid values. The recent association of remnant lipoproteins with atherosclerosis along with many factors that modulate remnant lipoprotein metabolism underscores the importance of recognising dysbetalipoproteinemia as an extreme state of remnant lipoprotein accumulation. Although there may be some differences between remnants in the general population and dysbetalipoproteinemia, it is clear that remnants promote atherosclerosis. Current treatment strategies are adequate but new strategies could also be of benefit in dysbetalipoproteinemia.