Lipid-lowering drugs and essential omega-6 and omega-3 fatty acids in patients with coronary heart disease

One-Year Effects of High-Intensity Statin on Bioactive Lipids: Findings From the JUPITER Trial

BACKGROUND

Statin effects extend beyond low-density lipoprotein cholesterol reduction, potentially modulating the metabolism of bioactive lipids (BALs), crucial for biological signaling and inflammation. These bioactive metabolites may serve as metabolic footprints, helping uncover underlying processes linked to pleiotropic effects of statins and yielding a better understanding of their cardioprotective properties. This study aimed to investigate the impact of high-intensity statin therapy versus placebo on plasma BALs in the JUPITER trial (Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin; NCT00239681), a randomized primary prevention trial involving individuals with low-density lipoprotein cholesterol <130 mg/dL and high-sensitivity C-reactive protein ≥2 mg/L.

METHODS

Using a nontargeted mass spectrometry approach, over 11 000 lipid features were assayed from baseline and 1-year plasma samples from cardiovascular disease noncases from 2 nonoverlapping nested substudies: JUPITERdiscovery (n=589) and JUPITERvalidation (n=409). The effect of randomized allocation of rosuvastatin 20 mg versus placebo on BALs was examined by fitting a linear regression with delta values (∆=year 1-baseline) adjusted for age and baseline levels of each feature. Significant associations in discovery were analyzed in the validation cohort. Multiple comparisons were adjusted using 2-stage overall false discovery rate.

RESULTS

We identified 610 lipid features associated with statin randomization with significant replication (overall false discovery rate, <0.05), including 26 with annotations. Statin therapy significantly increased levels of 276 features, including BALs with anti-inflammatory activity and arterial vasodilation properties. Concurrently, 334 features were significantly lowered by statin therapy, including arachidonic acid and proinflammatory and proplatelet aggregation BALs. By contrast, statin therapy reduced an eicosapentaenoic acid-derived hydroxyeicosapentaenoic acid metabolite, which may be related to impaired glucose metabolism. Additionally, we observed sex-related differences in 6 lipid metabolites and 6 unknown features.

CONCLUSIONS

Statin allocation was significantly associated with upregulation of BALs with anti-inflammatory, antiplatelet aggregation and antioxidant properties and downregulation of BALs with proinflammatory and proplatelet aggregation activity, supporting the pleiotropic effects of statins beyond low-density lipoprotein cholesterol reduction.

Effects of extra virgin olive oil and pecans on plasma fatty acids in patients with stable coronary artery disease

OBJECTIVE

The aim of this study was to determine the effects of a healthy diet supplemented with extra virgin olive oil or pecans on plasma fatty acids (PFAs) in patients with stable coronary artery disease (CAD).

METHODS

Patients 40 to 80 y of age were randomized to one of three dietary interventions (allocation ratio 1: 1: 1): healthy diet based on guidelines (control group [CG]), healthy diet supplemented with 30 g/d of pecans (PNG), or a healthy diet supplemented with 30 mL/d of extra virgin olive oil (OOG). PFAs were identified at baseline and at the end of follow-up (12 wk), and correlations between dietary fatty acids intake, PFAs, and clinical biomarkers of the lipid profile were also assessed before and after the interventions.

RESULTS

Among 149 participants included in the analysis (43 CG; 51 PNG; and 55 OOG), correlations were observed between food intake, PFAs, and lipid profile before and after interventions independent of statins used, but all were considered weak. At the end of the study, the OOG showed increased concentrations of oleic fatty acid independently of the type of statin in use (1.49%; 95% confidence interval, 0.08-2.89; P = 0.029); however, there were no significant differences between the groups regarding the final mean values of oleic fatty acid or in the other PFAs.

CONCLUSIONS

In patients with stable CAD, there were no significant differences in PFAs after 12 wk according to dietary interventions evaluated.

Omega-3 polyunsaturated fatty acids focusing on eicosapentaenoic acid and docosahexaenoic acid in the prevention of cardiovascular diseases: a review of the state-of-the-art

INTRODUCTION

: An epidemiological study of Greenlandic Inuit suggested the importance of omega-3 polyunsaturated fatty acids (PUFAs) in preventing ischemic heart disease. After this landmark study, large-scale epidemiological studies have examined the benefits of omega-3 PUFAs in the prevention of cardiovascular diseases.

AREAS COVERED

: This article reviews studies on omega-3 PUFAs, and identifies issues relevant to cardiovascular risk.

EXPERT OPINION

: Recent studies have focused on the anti-inflammatory effects of omega-3 PUFAs and specialized pro-resolving mediators. High-purity eicosapentaenoic acid (EPA) ethyl ester and EPA/docosahexaenoic acid (DHA) preparations have been developed primarily for the treatment of hypertriglyceridemia. Various trials on the cardiovascular protective effects of omega-3 PUFAs have been reported, but the results have not been consistent. Some issues of the trials have been suggested, such as using low-dose omega-3 PUFAs and not including hypertriglyceridemia in subject selection criteria. REDUCE-IT study that used a high dose of high-purity EPA preparation showed a relative reduction in cardiovascular events, but, the STRENGTH study that used a high dose of EPA/DHA preparation did not support this benefit. This article reviews the roles of omega-3 PUFAs in cardiovascular diseases, including progress in understanding the molecular mechanisms and recent large-scale clinical trials.

Prevention of Cardiovascular Events with Omega-3 Polyunsaturated Fatty Acids and the Mechanism Involved

An epidemiological study of Greenlandic Inuit suggested that fish oil, or omega-3 polyunsaturated fatty acids (PUFA), was important in preventing atherosclerotic disease. After this landmark study, many large-scale epidemiological studies and meta-analyses have examined the health benefits of omega-3 PUFA as part of a fatty acid-rich diet to demonstrate its beneficial roles in the prevention of cardiovascular diseases. Recent research has also focused attention on the anti-inflammatory effects of omega-3 PUFA and on specialized pro-resolving mediators. Findings of these studies have led to the development of omega-3 PUFA preparations for the treatment of dyslipidemia, including a highly purified eicosapentaenoic acid (EPA)-ethyl ester product (Epadel®) in Japan and an EPA/docosahexaenoic acid (DHA) preparation (Lotriga®) in the United States and Europe. Although various large-scale clinical trials on the cardiovascular preventive effect of omega-3 PUFA were conducted and reported, the results were not always consistent. The issues of not targeting subjects with hypertriglyceridemia and using low dose of omega-3 PUFA have been suggested to contribute to the failure of demonstrating the preventive effect of omega-3 PUFA in these clinical trials. Taking into account the above issues, the REDUCE-IT trial evaluated a highly purified EPA preparation at a high dose of 4 g/day in patients with hypertriglyceridemia and high cardiovascular risk, and demonstrated an extraordinary outcome of 25% relative reduction in cardiovascular events. This article reviews studies on omega-3 fatty acids during the last 50 years, including the progress in elucidating molecular mechanisms and recent large-scale clinical studies.

Lipids and Suicide Risk

In the search for biomarkers and modifiable risk factors for suicide, lipid status has garnered considerable interest, although the lipid-suicide connection is not without controversy. Major categories of lipids that have been reported as germane to suicide include sterols and polyunsaturated fatty acids (PUFAs). Research concerning lipid effects on mood and suicide risk includes epidemiologic approaches, cohort studies, and clinical trials. In general, current evidence suggests that higher n-3 relative to n-6 PUFA intake may have beneficial effects on depression and suicide risk, particularly in women, while low cholesterol may be detrimental in both sexes. Additionally, low estrogen in women has been associated with suicide attempts, whereas high androgen loads may contribute to the higher suicide completion rate in men. Basic and translational research provides strong evidence for several potential mechanisms that have been implicated in depression and suicide. Firstly, PUFAs, cholesterol, and estrogen can interact to influence structure and function of membrane microdomains ("lipid rafts"), with potential regulatory effects on inflammation and signal transduction, including monoaminergic signaling. Secondly, PUFAs bind to and activate peroxisome proliferator-activated receptors (PPARs), nuclear receptors that regulate gene expression, with resultant effects on inflammation and bioenergetics. Thirdly, PUFAs are both a target for and a hormetic regulator of oxidative stress. Critical to a greater understanding of lipid status as a suicide risk predictor and treatment target will be studies that map genomic and phenotypic characteristics of individuals whose emotional state is affected most by lipid status. Also important will be a more nuanced understanding of lipid-lipid interactions and the differential roles of lipid subclasses on suicide risk.

Fatty acid desaturase 2 is up-regulated by the treatment with statin through geranylgeranyl pyrophosphate-dependent Rho kinase pathway in HepG2 cells

Statins have been reported to increase the plasma concentration of arachidonic acid (AA), an omega-6 long chain polyunsaturated fatty acid (LCPUFA) in several clinical studies indicating that statins affect the endogenous synthesis of LCUFAs. In the present study, we investigated the roles of the intrinsic mevalonate cascade and Rho-dependent pathway in LCPUFA synthesis, especially focusing on fatty acid desaturases (Fads) 2, using the human hepatocellular carcinoma cell line HepG2. Cell number and the activity of caspase-3 and 7 (caspase-3/7) was measured using a commercial kit. Gene expression was analyzed by quantitative real-time PCR. Protein expression was detected by Western blot analysis. Atorvastatin decreased cell viability and increased caspase-3/7 activity in a dose-dependent manner. At lower concentrations, atorvastatin stimulated both mRNA and protein expression of Fads2, and increased mRNA expression of FADS1 and ELVOL5. Both mevalonate and geranylgeranyl-pyrophosphate (GGPP), but not cholesterol, fully reversed atorvastatin-induced upregulation of Fads2, and mevalonate-effected reversal was inhibited by treatment with the Rho-associated protein kinase inhibitor Y-27632. These data clearly demonstrated that in human HepG2 cells, statins affect the endogenous synthesis of LCPUFAs by regulation of not only Fads2, but also Fads1 and Elovl5, through the GGPP-dependent Rho kinase pathway.

How lipids may affect risk for suicidal behavior

Suicide and nonfatal suicidal behaviors are major causes of mortality and morbidity worldwide. Variability in rates of suicide and suicidal behaviors within and between countries has been attributed to population and individual risk factors, including economic status and cultural differences, both of which can have suicide risk effects mediated through a variety of factors, of which perhaps the least understood is the role of diet. We therefore review the scientific literature concerning two major dietary lipid classes, cholesterol and polyunsaturated fatty acids (PUFAs), that have been associated with higher risk of suicide attempts and suicide. We consider potential mechanistic intermediates including serotonin transporters and receptors, toll-like receptors (TLRs), nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and peroxisome proliferator activated receptors (PPARs). Based on this review, we describe a theoretical model linking cholesterol and PUFA status to suicide risk, taking into account the effects of cholesterol-lowering interventions on PUFA balance, membrane lipid microdomains (rafts) as a nexus of interaction between cholesterol and omega-3 PUFAs, and downstream effects on serotonergic neurotransmission and specific inflammatory pathways.

The Role of n-3 Long Chain Polyunsaturated Fatty Acids in Cardiovascular Disease Prevention, and Interactions with Statins

Decreases in global cardiovascular disease (CVD) mortality and morbidity in recent decades can be partly attributed to cholesterol reduction through statin use. n-3 long chain polyunsaturated fatty acids are recommended by some authorities for primary and secondary CVD prevention, and for triglyceride reduction. The residual risk of CVD that remains after statin therapy may potentially be reduced by n-3 long chain polyunsaturated fatty acids. However, the effects of concomitant use of statins and n-3 long chain polyunsaturated fatty acids are not well understood. Pleiotropic effects of statins and n-3 long chain polyunsaturated fatty acids overlap. For example, cytochrome P450 enzymes that metabolize statins may affect n-3 long chain polyunsaturated fatty acid metabolism and vice versa. Clinical and mechanistic study results show both synergistic and antagonistic effects of statins and n-3 long chain polyunsaturated fatty acids when used in combination.

Atorvastatin increases Fads1, Fads2 and Elovl5 gene expression via the geranylgeranyl pyrophosphate-dependent Rho kinase pathway in 3T3-L1 cells

Numerous clinical studies have reported that statins increase the plasma concentration of arachidonic acid, which is an ω-6 long-chain polyunsaturated fatty acid (LCPUFA), and decrease the concentrations of eicosapentaenoic acid and docosahexaenoic acid, which are ω‑3 LCPUFAs. These findings indicate that statins may affect the endogenous synthesis of LCPUFAs, which is regulated by fatty acid desaturases (FADSs) and elongation of very long‑chain fatty acids proteins (ELOVLs). The present study aimed to investigate the roles of the intrinsic mevalonate cascade and Rho‑dependent pathway in statin‑induced regulation of these desaturases and elongases, as well as cell viability using mouse 3T3‑L1 cells. mRNA expression was analyzed by quantitative polymerase chain reaction. Treatment with atorvastatin decreased cell viability and increased the mRNA expression levels of Fads1, Fads2 and ELOVL fatty acid elongase 5 (Elovl5) in a dose‑dependent manner. Mevalonate and geranylgeranyl pyrophosphate (GGPP), but not cholesterol, fully reversed the atorvastatin‑induced downregulation of cell viability and upregulation of gene expression; however, mevalonate itself did not affect cell viability and gene expression. The Rho‑associated protein kinase inhibitor Y‑27632 inhibited the mevalonate‑ and GGPP‑mediated reversal of atorvastatin‑induced upregulation of Fads1, Fads2 and Elovl5. These findings indicated that statins may affect the endogenous synthesis of LCPUFAs by regulating Fads1, Fads2 and Elovl5 gene expression via the GGPP‑dependent Rho kinase pathway in mouse 3T3-L1 cells.

Risk factors associated with plasma omega-3 fatty acid levels in patients with suspected coronary artery disease

INTRODUCTION

We sought to determine the associations between plasma eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels and various cardiovascular risk factors and with the use of fish oil supplements (FOS).

PATIENTS AND METHODS

Patients with suspected coronary artery disease (CAD) undergoing cardiac catheterization (n=433) were studied. Serum fatty acid (FA) composition, the concentrations of lipids and biomarkers of oxidative stress, and dietary/lifestyle factors were measured.

RESULTS

FOS use was associated with a higher plasma EPA+DHA levels (3.7±1.5 vs. 2.6±1.1%, p<0.0001). However, there was no relationship between FOS dose (mg/day) and EPA+DHA levels in 76 patients reporting FOS use (r=-0.21, p=0.07). Lower levels were inversely associated with risk factor profiles including lower ApoB100/ApoA1 ratios (p<0.001).

DISCUSSION AND CONCLUSIONS

Higher EPA+DHA levels characterized patients with lower CAD risk. The lack of relations between FOS dose and plasma EPA+DHA levels likely reflects uncaptured variability in EPA+DHA content of supplements.

Do statins increase and Mediterranean diet decrease the risk of breast cancer?

BACKGROUND

Physical exercise and healthy dietary habits are recommended to prevent breast cancer.

DISCUSSION

Increased intake of omega-3 fatty acids associated with decreased omega-6 - resulting in higher omega-3 to omega-6 ratio compared with Western-type diet - is inversely associated with breast cancer risk. The modernized Mediterranean diet with high omega-3 to omega-6 ratio, high fiber and polyphenol intake, and consumption of low-glycemic index foods reduces overall cancer risk and specifically breast cancer risk. It has been suggested that consuming no more than one alcoholic drink per day, preferably wine, is preferable. Eliminating environmental contaminants, including endocrine disruptors, and favoring organic foods to increase polyphenol intake and the omega-3 to omega-6 ratios were also shown to be beneficial. Cholesterol-lowering statins may decrease antitumor defenses; are toxic for the mitochondria; decrease the omega-3 to omega-6 ratio; increase body mass index, insulin resistance and diabetic risk; and have been associated with an increased breast cancer risk.

SUMMARY

Therefore, as well as making lifestyle changes to decrease breast cancer risk, we argue that physicians should carefully consider (and often avoid) therapies that may increase breast cancer or diabetes risk in high-risk women and women who wish to decrease their breast cancer risk.

The Role of Essential Fatty Acids in Human Health

Fatty acid research began about 90 years ago but intensified in recent years. Essential fatty acids (linoleic and α-linolenic) must come from diet. Other fatty acids may come from diet or may be synthesized. Fatty acids are major components of cell membrane structure, modulate gene transcription, function as cytokine precursors, and serve as energy sources in complex, interconnected systems. It is increasingly apparent that dietary fatty acids influence these vital functions and affect human health. While the strongest evidence for influence is found in cardiovascular disease and mental health, many additional conditions are affected. Problematic changes in the fatty acid composition of human diet have also taken place over the last century. This review summarizes current understanding of the pervasive roles of essential fatty acids and their metabolites in human health.

Recent findings on the health effects of omega-3 fatty acids and statins, and their interactions: do statins inhibit omega-3?

Early randomized controlled trials (RCTs) demonstrated the health benefits of omega-3 fatty acids (n-3), whereas recent RCTs were negative. We now address the issue, focusing on the temporal changes having occurred: most patients in recent RCTs are no longer n-3 deficient and the vast majority are now treated with statins. Recent RCTs testing n-3 against arrhythmias suggest that n-3 reduce the risk only in patients not taking a statin. Other recent RCTs in secondary prevention were negative although, in a post-hoc analysis separating statin users and non-users, non-significant protection of n-3 was observed among statin non-users whereas statin users had no effect. Recent RCTs testing statins - after the implementation of the New Clinical Trial Regulation in 2007 - are negative (or flawed) suggesting that the lack of effect of n-3 cannot be attributed to a parallel protection by statins. Finally, statins favor the metabolism of omega-6 fatty acids (n-6), which in turn inhibits n-3 and, contrary to n-3, they increase insulin resistance and the risk of diabetes. Thus, n-3 and statins are counteractive at several levels and statins appear to inhibit n-3.

Fatty acids as biocompounds: their role in human metabolism, health and disease: a review. part 2: fatty acid physiological roles and applications in human health and disease

BACKGROUND

This is the second of two review parts aiming at describing the major physiological roles of fatty acids, as well as their applications in specific conditions related to human health.

RESULTS

The review included the current literature published in Pubmed up to March 2011. In humans, fatty acids are a principle energy substrate and structural components of cell membranes (phospholipids) and second messengers. Fatty acids are also ligands of nuclear receptors affecting gene expression. Longer-chain (LC) polyunsaturated fatty acids (PUFA), including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid are precursors of lipid mediators such as eicosanoids (prostaglandins, leukotrienes, thromboxanes), resolvins and neuroprotectins. Lipid mediators produced by EPA and DHA (LC n-3 PUFA; mainly found in oily fish) are considered as inflammation-resolving, and thus, fish oil has been characterised as antiinflammatory. Recommendations for EPA plus DHA intake from oily fish vary between 250-450 mg/day. Dietary reference values for fat vary between nutrition bodies, but mainly agree on a low total and saturated fat intake. The existing literature supports the protective effects of LC n-3 PUFA (as opposed to n-6 PUFA and saturated fat) in maternal and offspring health, cardiovascular health, insulin sensitivity, the metabolic syndrome, cancer, critically ill patients, and immune system disorders.

CONCLUSION

Fatty acids are involved in multiple pathways and play a major role in health. Further investigation and a nutrigenomics approach to the effects of these biocompounds on health and disease development are imperative and highlight the importance of environmental modifications on disease outcome.

New insights into the health effects of dietary saturated and omega-6 and omega-3 polyunsaturated fatty acids

Cardiovascular diseases and cancers are leading causes of morbidity and mortality. Reducing dietary saturated fat and replacing it with polyunsaturated fat is still the main dietary strategy to prevent cardiovascular diseases, although major flaws have been reported in the analyses supporting this approach. Recent studies introducing the concept of myocardial preconditioning have opened new avenues to understand the complex interplay between the various lipids and the risk of cardiovascular diseases. The optimal dietary fat profile includes a low intake of both saturated and omega-6 fatty acids and a moderate intake of omega-3 fatty acids. This profile is quite similar to the Mediterranean diet. On the other hand, recent studies have found a positive association between omega-6 and breast cancer risk. In contrast, omega-3 fatty acids do have anticancer properties. It has been shown that certain (Mediterranean) polyphenols significantly increase the endogenous synthesis of omega-3 whereas high intake of omega-6 decreases it. Finally, epidemiological studies suggest that a high omega-3 to omega-6 ratio may be the optimal strategy to decrease breast cancer risk. Thus, the present high intake of omega-6 in many countries is definitely not the optimal strategy to prevent cardiovascular disease and cancers. A moderate intake of plant and marine omega-3 in the context of the traditional Mediterranean diet (low in saturated and omega-6 fatty acids but high in plant monounsaturated fat) appears to be the best approach to reduce the risk of both cardiovascular diseases and cancers, in particular breast cancer.

Dietary flavonoids increase plasma very long-chain (n-3) fatty acids in rats

Flavonoids probably contribute to the health benefits associated with the consumption of fruit and vegetables. However, the mechanisms by which they exert their effects are not fully elucidated. PUFA of the (n-3) series also have health benefits. Epidemiological and clinical studies have suggested that wine flavonoids may interact with the metabolism of (n-3) PUFA and increase their blood and cell levels. The present studies in rats were designed to assess whether flavonoids actually increase plasma levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the main very long-chain (n-3) PUFA. Rats were fed a corn-derived anthocyanin (ACN)-rich (ACN-rich) or ACN-free diet with constant intakes of plant and marine (n-3) PUFA for 8 wk (Expt. 1). Plasma fatty acids were measured by GC. The ACN-rich diet contained ~0.24 ± 0.01 mg of ACN/g pellets. There were no significant differences between groups in the main saturated, monounsaturated, and (n-6) fatty acids. In contrast, plasma EPA and DHA were greater in the ACN-rich diet group than in the ACN-free diet group (P < 0.05). We obtained similar results in 2 subsequent experiments in which rats were administered palm oil (80 μL/d) and consumed the ACN-rich or ACN-free diet (Expt. 2) or were supplemented with fish oil (60 mg/d, providing 35 mg DHA and 12 mg EPA) and consumed the ACN-rich or ACN-free diet (Expt. 3). In both experiments, plasma EPA and DHA were significantly greater in the ACN-rich diet group. These studies demonstrate that the consumption of flavonoids increases plasma very long-chain (n-3) PUFA levels. These data confirm previous clinical and epidemiological studies and provide new insights into the health benefits of flavonoids.

Bezafibrate mildly stimulates ketogenesis and fatty acid metabolism in hypertriglyceridemic subjects

Our objective was to determine whether bezafibrate, a hypotriglyceridemic drug and peroxisome proliferator-activated receptor (PPAR)-alpha agonist, is ketogenic and increases fatty acid oxidation in humans. We measured fatty acid metabolism and ketone levels in 13 mildly hypertriglycemic adults (67 +/- 11 years old) during 2 metabolic study days lasting 6 h, 1 day before and 1 day after bezafibrate (400 mg of bezafibrate per day for 12 weeks). beta-Hydroxybutyrate, triglycerides, free fatty acids, fatty acid profiles, insulin, and glucose were measured in plasma, and fatty acid beta-oxidation was measured in breath after an oral 50-mg dose of the fatty acid tracer [U-(13)C]linoleic acid. As expected, 12 weeks on bezafibrate decreased plasma triglycerides by 35%. Bezafibrate tended to raise postprandial beta-hydroxybutyrate, an effect that was significant after normalization to the fasting baseline values (p = 0.03). beta-Oxidation of [U-(13)C]linoleic acid increased by 30% (p = 0.03) after treatment. On the metabolic study day after bezafibrate treatment, postprandial insulin decreased by 26% (p = 0.01), and glucose concentrations were lower 2 to 5 h postprandially. Thus, in hypertriglyceridemic individuals, bezafibrate is mildly ketogenic and significantly changes fatty acid metabolism, effects that may be linked to PPARalpha stimulation and to moderately improved glucose metabolism.

Relationship between n-3 and n-6 plasma fatty acid levels and insulin resistance in coronary patients with and without metabolic syndrome

BACKGROUND AND AIMS

Animal studies show that ecosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are effective for the prevention and treatment of insulin resistance (IR). Data from human studies are contradictory. We sought to determine whether the relationships between plasma n-3 and n-6 polyunsaturated fatty acid (FA) levels and IR differ according to the presence or absence of metabolic syndrome (MS) in a coronary heart disease sample.

METHOD AND RESULTS

Clinical, metabolic parameters, plasma phospholipid FA profiles and indirect measurement of IR (homeostatic model assessment-HOMA) were measured in 734 subjects, 8 weeks following acute coronary syndrome. FA levels and their correlations with IR were compared in subjects with and without MS. MS patients had higher saturated (16:0, 18:0) and n-6 (18:3n-6, 20:3n-6, 22:4n-6, 22:5n-6) FA levels, and lower EPA and DHA levels. HOMA-IR correlated positively with total saturated (r=0.13, P=0.017) and n-6 (r=0.17, P=0.001) FA levels and negatively with total n-3 FA levels (r=-0.13, P=0.012), in MS subjects only. Total n-3 and n-6 FAs and n-6/n-3 ratio were associated with HOMA-IR levels in MS subjects independent of total saturated FA levels, age, sex, sedentary behaviour, smoking, waist circumference, triglycerides, HDL-cholesterol, and systolic blood pressure.

CONCLUSIONS

Relationships between polyunsaturated FA type and IR vary according to the presence or absence of MS. N-3 FAs including EPA and DHA are associated with lower HOMA-IR, while the opposite is true for n-6 FAs. Prospective studies are required to address the potential effects of intermediate dose EPA and DHA on glucose handling in MS patients.

Heat-moisture treatment of high-amylose corn starch increases dietary fiber content and lowers plasma cholesterol in ovariectomized rats

The effect of dietary high-amylose corn starch (HACS) of varying dietary fiber (DF) content on plasma cholesterol was examined in ovariectomized (OVX) rats. Gelatinized normal corn starch (G-CS) was used as a reference. OVX rats were fed a fiber-free purified diet containing G-CS, HACS, gelatinized high-amylose corn starch (G-HACS), or heat-moisture treated HACS (HM-HACS) at 400 g starch/kg diet for 21 d. The DF content of G-CS, HACS, G-HACS, and HM-HACS measured by the AOAC method was 0.1, 19.3, 2.4, and 64.5 g/100 g, respectively. The dry weight of cecal contents, cecal wall weight, the amount of short chain fatty acids in cecal contents, the amount of bile acids in small intestinal contents, and fecal excretion of neutral sterols increased logarithmically with increasing DF, while total plasma cholesterol concentration decreased. On the other hand, hepatic CYP7A1 activity, fecal dry weight, and fecal excretion of bile acids increased linearly with increasing DF, while body weight gain decreased. The hypocholesterolemic effect of HACS in OVX-rats appeared to be more effective by heat-moisture treatment.

Effect of fenofibrate on the need for laser treatment for diabetic retinopathy (FIELD study): a randomised controlled trial

BACKGROUND

Laser treatment for diabetic retinopathy is often associated with visual field reduction and other ocular side-effects. Our aim was to assess whether long-term lipid-lowering therapy with fenofibrate could reduce the progression of retinopathy and the need for laser treatment in patients with type 2 diabetes mellitus.

METHODS

The Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study was a multinational randomised trial of 9795 patients aged 50-75 years with type 2 diabetes mellitus. Eligible patients were randomly assigned to receive fenofibrate 200 mg/day (n=4895) or matching placebo (n=4900). At each clinic visit, information concerning laser treatment for diabetic retinopathy-a prespecified tertiary endpoint of the main study-was gathered. Adjudication by ophthalmologists masked to treatment allocation defined instances of laser treatment for macular oedema, proliferative retinopathy, or other eye conditions. In a substudy of 1012 patients, standardised retinal photography was done and photographs graded with Early Treatment Diabetic Retinopathy Study (ETDRS) criteria to determine the cumulative incidence of diabetic retinopathy and its component lesions. Analyses were by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN64783481.

FINDINGS

Laser treatment was needed more frequently in participants with poorer glycaemic or blood pressure control than in those with good control of these factors, and in those with a greater burden of clinical microvascular disease, but the need for such treatment was not affected by plasma lipid concentrations. The requirement for first laser treatment for all retinopathy was significantly lower in the fenofibrate group than in the placebo group (164 [3.4%] patients on fenofibrate vs 238 [4.9%] on placebo; hazard ratio [HR] 0.69, 95% CI 0.56-0.84; p=0.0002; absolute risk reduction 1.5% [0.7-2.3]). In the ophthalmology substudy, the primary endpoint of 2-step progression of retinopathy grade did not differ significantly between the two groups overall (46 [9.6%] patients on fenofibrate vs 57 [12.3%] on placebo; p=0.19) or in the subset of patients without pre-existing retinopathy (43 [11.4%] vs 43 [11.7%]; p=0.87). By contrast, in patients with pre-existing retinopathy, significantly fewer patients on fenofibrate had a 2-step progression than did those on placebo (three [3.1%] patients vs 14 [14.6%]; p=0.004). An exploratory composite endpoint of 2-step progression of retinopathy grade, macular oedema, or laser treatments was significantly lower in the fenofibrate group than in the placebo group (HR 0.66, 95% CI 0.47-0.94; p=0.022).

INTERPRETATION

Treatment with fenofibrate in individuals with type 2 diabetes mellitus reduces the need for laser treatment for diabetic retinopathy, although the mechanism of this effect does not seem to be related to plasma concentrations of lipids.

Preparation and physical characterization of a novel marine oil emulsion as a potential new formulation vehicle for lipid soluble drugs

Emulsions often contain vegetable oils such as soybean oil. In this study, a 10% (w/w) of marine mammal oil emulsion was prepared. The effect of a group of emulsifying agents on the stability of the 10% of seal oil emulsion was examined. The emulsifying agents studied were hydrogenated castor oil coated with various polyoxyethylene derivatives. It was found that 2.5% of HCO-40 resulted in the most stable seal oil emulsion. The size of the emulsified droplets defined by their diameters was found to be around 240-270 nm. The initial zeta-potential and pH value of the emulsion were found to be around -27 mV and 3.5, respectively, which decreased over time, to about -31 mV and 2.4, respectively. This is believed to be a result of the hydrolysis of triacylglycerides into free fatty acids in the emulsion. The effect of various amounts of Crodasinic LS-30, a negatively charged surfactant, and Incroqal Behenyl TMS, a positively charged surfactant, on the emulsion was investigated. It was shown that Crodasinic LS-30 had very little effect on the particle size, zeta-potential and pH, while the effect of Incroquat Benhenyl TMS was found to be dependent upon the concentration of the surfactant used.

The emerging link between nutrition, inflammation and atherosclerosis

A number of dietary components modulate the inflammatory response in humans, thereby affecting cardiovascular risk. As basic research provides a better understanding of the molecular mechanisms of vascular function regulation by nutrients, clinical investigation and outcome studies demonstrate the relevance of dietary factors to the prevention and treatment of vascular disease. Benefits of dietary interventions may be attributable to weight loss or to more specialized mechanisms in which inflammation is targeted directly. Available evidence indicates that dietary intervention should be an integral part of therapeutic approaches for treating conditions such as the metabolic syndrome and, ultimately, for the prevention of cardiovascular disease.

n-3 fatty acids and the metabolic syndrome

The metabolic syndrome is defined as the coexistence of 3 or more components, some of which indicate alterations in glucose and lipid metabolism. The prevalence of the metabolic syndrome is rapidly increasing in relation to obesity, and it is considered to be an important predictor of cardiovascular disease. Increased intakes or supplements of n-3 marine fatty acids may improve defects in insulin signaling and prevent alterations in glucose homeostasis and the further development of type 2 diabetes. This is largely mediated through a reduction in fatty acid accumulation in muscle and liver. n-3 Polyunsaturated fatty acids (n-3 PUFAs) reduce plasma triacylglycerols and improve the lipoprotein profile by decreasing the fraction of atherogenic small, dense LDL. However, n-3 PUFAs do not lower LDL cholesterol. These effects are likely mediated through the activity of transcription factors relating to expression of genes involved in lipid oxidation and synthesis. Other pleiotrophic effects of n-3 PUFAs may contribute to decreasing the burden of the metabolic syndrome, such as modulating inflammation, platelet activation, endothelial function, and blood pressure. Although studies comparing the effect of both major n-3 PUFAs are limited, docosahexaenoic acid appears at least as efficient as eicosapentaenoic acid in correcting several risk factors. The use of n-3 PUFAs should be considered in more global strategies including changes in lifestyle, such as adhering to a healthy Mediterranean type of diet and practicing regular physical exercise.