The balance of omega-3 polyunsaturated fatty acids for -reducing residual risks in patients with coronary artery disease

Effects of Daily Consumption of Scallop Oil Prepared from Internal Organs of Japanese Giant Scallop (Patinopecten yessoensis) on Serum Lipid Composition and Its Safety: A Randomized, Double-blind, Placebo-controlled, Parallel Group Comparison Study

Scallop oil (SCO) prepared from the internal organs of the Japanese giant scallop (Patinopecten yessoensis) contains eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and phospholipids (PL). It was previously shown that SCO consumption improves cholesterol and triacylglycerols (TG) contents in mice. The present study demonstrated the effects of daily SCO consumption (1.2 g/day, containing 376 mg of EPA, 63 mg of DHA, and 150 mg of PL) for 12 weeks in human subjects. In this randomized, doubleblind, placebo-controlled, parallel group comparison study, 70 Japanese subjects with serum TG levels ≥120 but < 200 mg/dL were recruited and randomly assigned to the SCO or placebo group. All subjects ingested six capsules per day for 12 weeks. We conducted medical interviews, body composition measurements, vital sign examinations, and blood sampling at weeks 0 (baseline), 4, 8, and 12, and measured peripheral blood flow at weeks 0 and 12. In the case of subjects with higher serum TG levels, SCO consumption decreased the changes in serum TG and malondialdehyde-low density lipoprotein (MDA-LDL) levels compared with the placebo group. Safety assessment revealed no medically significant changes due to continuous SCO consumption. The findings indicate that 1.2 g/day of SCO consumption may be beneficial for reducing serum TG and MDA-LDL levels in persons with higher TG levels.

Effects of Commercially Available Antioxidant-Enriched Fish- and Chicken-Based Diets on Biochemical Parameters and Blood Fatty Acid Profile of Old Dogs

The aim of this study was to evaluate the effects of two commercially available fish- (FH) and chicken (CH)-based diets and the same diets combined with antioxidant compounds, e.g., FH-AOX and CH-AOX, respectively, on biochemical parameters and blood fatty acid (FA) profile. For this purpose, 28 dogs were allocated to four groups and fed the four diets for six months. Blood samples were taken before starting the experimental period and at the end of the trial. Concerning the biochemical parameters, the animals fed CH-AOX reached the highest values for ALB compared to the animals fed CH or FH-AOX; however, the values were within the reference values for old dogs. Triglycerides and urea were significantly higher in FH compared to the CH diet; however, both FH-AOX and CH-AOX showed a marked decrease in the TRI and urea concentration with respect to FH and CH. Moreover, CH-AOX and FH-AOX increased glucose values, linoleic acid content, and polyunsaturated FA n-3 with respect to FH and CH. On the contrary, arachidonic acid was lower in the CH-AOX and FH-AOX groups. In conclusion, FH led to a better FA profile than that of the CH diet, while CH-AOX and FH-AOX improved the FA profile regardless of the basal diet.

Defining the Role of Icosapent Ethyl in Clinical Practice

The health benefit of fish oil, i.e. omega-3 fatty acids (ω-3 FA) has a long history of debate. While there are a number of medications to reduce serum triglyceride levels, none have shown unanimous cardiovascular (CV) benefits. The most recent Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT) assessing the CV outcome of one highly purified prescription ω-3 FA has certainly rejuvenated the debate. While this trial has been regarded as one of the most important landmark trials in preventive cardiology, the tolerability issue in a very high dose (4 g/day, as administered in the trial) is still a matter of concern. This article summarizes the current status and future perspective of icosapent ethyl in clinical practice in light of REDUCE-IT.

Association between the ratio of serum n-3 to n-6 polyunsaturated fatty acids and acute coronary syndrome in non-obese patients with coronary risk factor: a multicenter cross-sectional study

Background

Previous studies have reported that being overweight, obese, or underweight is a risk factor for ischemic cardiovascular disease (CVD); however, CVD also occurs in subjects with ideal body mass index (BMI). Recently, the balance of n-3/n-6 polyunsaturated fatty acids (PUFAs) has received attention as a risk marker for CVD but, so far, no study has been conducted that investigates the association between BMI and the balance of n-3/n-6 PUFAs for CVD risk.

Methods

We evaluated the association between n-3/n-6 PUFA ratio and acute coronary syndrome (ACS) in three BMI-based groups (< 25: low BMI, 25–27.5: moderate BMI, and ≥ 27.5: high BMI) that included 1666 patients who visited the cardiovascular medicine departments of five hospitals located in urban areas in Japan.

Results

The prevalence of ACS events was 9.2, 7.3, and 10.3% in the low, moderate, and high BMI groups, respectively. We analyzed the relationship between ACS events and several factors, including docosahexaenoic acid/arachidonic acid (DHA/AA) ratio by multivariate logistic analyses. In the low BMI group, a history of smoking (odds ratio [OR]: 2.47, 95% confidence interval [CI]: 1.40–4.35) and low DHA/AA ratio (OR: 0.30, 95% CI: 0.12–0.74) strongly predicted ACS. These associations were also present in the moderate BMI group but the magnitude of the association was much weaker (ORs are 1.47 [95% CI: 0.54–4.01] for smoking and 0.63 [95% CI: 0.13–3.10] for DHA/AA). In the high BMI group, the association of DHA/AA (OR: 1.98, 95% CI: 0.48–8.24) was reversed and only high HbA1c (OR: 1.46, 95% CI: 1.03–2.08) strongly predicted ACS. The interaction test for OR estimates (two degrees of freedom) showed moderate evidence for reverse DHA/AA ratio–ACS associations among the BMI groups (P = 0.091).

Conclusions

DHA/AA ratio may be a useful marker for risk stratification of ACS, especially in non-obese patients.

Optimal Dose of n-3 Polyunsaturated Fatty Acids for Cardiovascular Event Prevention

Background: The n-3 polyunsaturated fatty acids (PUFA), represented by eicosapentaenoic acid (EPA) and docosahexaenoic acid, have anti-atherogenic effects (e.g., neutral fat-lowering effects) and other beneficial effects such as antiplatelet, anti-inflammatory, plaque stabilizing, vascular endothelial function ameliorative, antihypertensive, and anti-arrhythmic effects. Epidemiological studies and clinical trials have assessed the inhibitory effects of n-3 PUFA on cardiovascular events. Methods and Results: Studies that reported positive outcomes, such as the Japan EPA Lipid intervention Study (JELIS) and the Cardiovascular Risk Reduction with Icosapent Ethyl for Hypertriglyceridemia (REDUCE-IT), noted a tendency toward the use of high-dose n-3 PUFA (1.8-4 g/day). The Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico-Prevenzione (GISSI-Prevenzione) trial and the JELIS had high EPA/arachidonic acid (AA) baseline ratios. In contrast, negative outcome studies, such as the Outcome Reduction with an Initial Glargine Intervention (ORIGIN) trial, Risk and Prevention study, A Study of Cardiovascular Events in Diabetes (ASCEND), and the Vitamin D and Omega-3 Trial (VITAL) had participants who tended to use low-dose n-3 PUFA (0.84-1 g/day) and to have low baseline EPA/AA. Conclusions: Differences in baseline EPA/AA ratio and the EPA/AA ratio threshold for the prevention of cardiovascular events seem to contribute to the different outcomes, together with the dose of n-3 PUFA.

Metabolic indices of polyunsaturated fatty acids: current evidence, research controversies, and clinical utility

The n-3 and n-6 polyunsaturated fatty acids (PUFA) are among the most studied nutrients in human metabolism. In the past few decades, prospective studies and controlled trials have supported the view that the effects of these essential fatty acids are clinically relevant. PUFA profiles in different blood compartments are reflections of both diet and metabolism, and their levels may be related to disease risk. Despite widespread interest, there is no consensus regarding which biomarkers best reflect PUFA status in the body. The measurement of PUFA levels is not straight-forward, and a wide variety of indices have been used in clinical studies, producing conflicting results. A major source of heterogeneity among studies is associated with research design, sampling, and laboratory analyses. To date, the n-3 index, n-6/n-3 ratio, and arachidonic acid (AA)/eicosapentaenoic acid (EPA) ratio are the most promising biomarkers associated with PUFA metabolism. Although hotly debated, these indices may be considered at least markers, if not risk factors, for several diseases, especially cardiovascular events and brain disorders. Here, we summarize the most updated evidence of n-3 and n-6 PUFA effects on human health, reviewing current controversies on the aforementioned indices and whether they can be considered valuable predictors of clinical outcomes.

Rounding the corner on residual risk: Implications of REDUCE-IT for omega-3 polyunsaturated fatty acids treatment in secondary prevention of atherosclerotic cardiovascular disease

Patients with established atherosclerotic cardiovascular (CV) disease remain at increased risk of major adverse cardiovascular events even during optimal lipid-lowering therapy. Recent studies using the methods of Mendelian randomization, as well as analyses of data from large statin trials, have concluded that elevated triglyceride (TG) levels contribute to that increased risk. Omega-3 polyunsaturated fatty acids (omega-3 PUFAs) from fish and shellfish (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) reduce TG levels when added to the diet in sufficient amounts, and they have favorable effects on several other markers of CV risk. However, trials of omega-3 PUFAs have had inconsistent findings regarding CV risk reduction. Recently, the REDUCE-IT (Reduction of Cardiovascular Events with EPA-Intervention Trial) trial reported that treatment of such high-risk patients with icosapent ethyl, a purified and stabilized ethyl ester of EPA, reduced the risk of the trial's primary CV endpoint by 25% (95% confidence intervals [CI], 32%-17%; P < .001). To appreciate the clinical implications of this result, it is important to understand how the REDUCE-IT trial differed from previous trials, especially with regard to patient enrollment criteria and treatment dosing. We discuss these design features relative to other trials. TG lowering can account for only part of the risk reduction seen with icosapent ethyl; we also consider other potential contributory mechanisms.

The eicosapentaenoic acid:arachidonic acid ratio and its clinical utility in cardiovascular disease

Eicosapentaenoic acid (EPA) is a key anti-inflammatory/anti-aggregatory long-chain polyunsaturated omega-3 fatty acid. Conversely, the omega-6 fatty acid, arachidonic acid (AA) is a precursor to a number of pro-inflammatory/pro-aggregatory mediators. EPA acts competitively with AA for the key cyclooxygenase and lipoxygenase enzymes to form less inflammatory products. As a result, the EPA:AA ratio may be a marker of chronic inflammation, with a lower ratio corresponding to higher levels of inflammation. It is now well established that inflammation plays an important role in cardiovascular disease. This review examines the role of the EPA:AA ratio as a marker of cardiovascular disease and the relationship between changes in the ratio (mediated by EPA intake) and changes in cardiovascular risk. Epidemiological studies have shown that a lower EPA:AA ratio is associated with an increased risk of coronary artery disease, acute coronary syndrome, myocardial infarction, stroke, chronic heart failure, peripheral artery disease, and vascular disease. Increasing the EPA:AA ratio through treatment with purified EPA has been shown in clinical studies to be effective in primary and secondary prevention of coronary artery disease and reduces the risk of cardiovascular events following percutaneous coronary intervention. The EPA:AA ratio is a valuable predictor of cardiovascular risk. Results from ongoing clinical trials will help to define thresholds for EPA treatment associated with better clinical outcomes.