Evangelos Oikonomou

Omega-3 PUFAs improved endothelial function and arterial stiffness with a parallel antiinflammatory effect in adults with metabolic syndrome

OBJECTIVES Metabolic syndrome (MetS) is associated with adverse cardiovascular events, and impaired vascular function. In this study we evaluated the effects of omega-3 polyunsaturated fatty acids (PUFAs) supplementation on vascular function, inflammatory and fibrinolytic process in subjects with MetS. METHODS We studied the effect of a 12 weeks oral treatment with 2 g/day of omega-3 PUFAs in 29 (15 male) subjects (mean age 44 ± 12 years) with MetS on three occasions (day0: baseline, day 28 and day 84). The study was carried out on two separate arms (PUFAs and placebo), according to a randomized, placebo-controlled, double-blind, cross-over design. The diagnosis of MetS was based on the guidelines of Adult Treatment Panel III definition. Endothelial function was evaluated by flow-mediated dilation (FMD) of the brachial artery. Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness. Serum levels of interleukin-6(IL-6) and plasminogen activator inhibitor-1(PAI-1) were measured by ELISA. RESULTS Treatment with PUFAs resulted in a significant improvement from day 0 to 28 and 84 in FMD and PWV (p < 0.001 for all). Nevertheless, treatment with placebo resulted in no significant changes in FMD (p = 0.63) and PWV (p = 0.17). Moreover, PUFAs treatment, compared to placebo, decreased IL-6 levels (p = 0.03) and increased PAI-1 levels (p = 0.03). Finally, treatment with PUFAs resulted in a significant decrease in fasting triglyceride levels from day 0 to 28 and 84 (p < 0.001) and in serum total cholesterol levels (p < 0.001). CONCLUSIONS In subjects with MetS, treatment with omega-3 PUFAs improved endothelial function and arterial stiffness with a parallel antiinflammatory effect.

Serum osteoprotegerin and osteopontin levels are associated with arterial stiffness and the presence and severity of coronary artery disease

BACKGROUND Osteopontin (OPN) and osteoprotegerin (OPG) have recently emerged as key factors in both vascular remodeling and development of atherosclerosis. Arterial stiffness has an independent predictive value for cardiovascular events. We evaluate the relationship between OPG, OPN serum levels and vascular function in coronary artery disease (CAD) patients. METHODS The study population was consisted of 409 subjects (280 with CAD and 129 without CAD). Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness. OPG and OPN levels were measured, as markers of vascular remodeling and calcification, by ELISA. Gensini score was used to evaluate the extent of CAD. RESULTS CAD patients, compared to those without CAD, had higher OPG (3.91 ± 1.87 pmol/l vs. 2.88 ± 1.32 pmol/l, p<0.001) and logOPN levels (1.81 ± 0.18 ng/ml vs. 1.71 ± 0.24 ng/ml, p<0.001) and impaired PWV (8.94 ± 2.21 m/s vs. 8.28 ± 1.91 m/s, p=0.006). Furthermore, PWV was associated with serum OPG levels (r=0.19, p<0.001) and with serum logOPN levels (r=0.10, p=0.049). Multivariate linear regression analysis revealed that increased OPG (p=0.013) and logOPN (p=0.006) levels are associated with 3-vessel CAD and Gensini score (p=0.04 for OPG and p=0.09 for OPN), independently of other known cardiovascular risk factors. CONCLUSION The present study revealed that serum OPG and OPN levels are positively associated with arterial stiffness, and with the extent of CAD. These preliminary results suggest that OPG and OPN levels are significantly correlated with vascular function contributing to the pathogenesis of atherosclerosis in CAD. Further studies are needed to explore the mechanisms of action of OPG and OPN in CAD.

Inflammatory cytokines in atherosclerosis: current therapeutic approaches

The notion of atherosclerosis as a chronic inflammatory disease has intensified research on the role of cytokines and the way these molecules act and interact to initiate and sustain inflammation in the microenvironment of an atherosclerotic plaque. Cytokines are expressed by all types of cells involved in the pathogenesis of atherosclerosis, act on a variety of targets exerting multiple effects, and are largely responsible for the crosstalk among endothelial, smooth muscle cells, leucocytes, and other vascular residing cells. It is now understood that widely used drugs such as statins, aspirin, methotrexate, and colchicine act in an immunomodulatory way that may beneficially affect atherogenesis and/or cardiovascular disease progression. Moreover, advancement in pharmaceutical design has enabled the production of highly specific antibodies against key molecules involved in the perpetuation of the inflammatory cascade, raising hope for advances in the treatment of atherosclerosis. This review describes the actions and effects of these agents, their potential clinical significance, and future prospects.

Flavonoids in atherosclerosis: an overview of their mechanisms of action.

Polyphenols are composed of a wide variety of molecules that are classified into several categories, according to their chemical type such as phenolic acids, flavonoids, stilbenes, and lignans. Many studies have proven the beneficial effects of flavonoids in atherosclerosis progression and cardiovascular disease. Dietary flavonoids reduce oxidative stress and exert anti-inflammatory actions. Moreover, flavonoids have the ability to avoid the thrombus formation, improve endothelial function, modify lipid levels and regulate glucose metabolism. In the context of this evidence in this review article we summarize the so far acquired knowledge of the most important mechanisms of action of flavonoids in atherosclerosis progression.

Effects of omega-3 fatty acids on endothelial function, arterial wall properties, inflammatory and fibrinolytic status in smokers: A cross over study

BACKGROUND Smoking is associated with endothelial dysfunction and arterial stiffness. Supplementation of Ω-3 PUFAs is associated with better prognosis. Aim of this study was to evaluate the effects of Ω-3 polyunsaturated fatty acids (PUFAs) supplementation on smoking-induced impairment of arterial function. METHODS We studied the effect of a 12 weeks oral treatment with 2gr/day of Ω-3 PUFAs in 20 healthy smokers on three occasions (day 0:baseline, day 28 and day 84). The study was carried out on two separate arms (Ω-3 fatty acids and placebo), according to a randomized, placebo-controlled, double-blind, cross-over design. Measurements were carried out before (pSm), immediately and 20min after cigarette smoking. Endothelial function was evaluated by flow-mediated dilation (FMD) of the brachial artery. Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness and augmentation index (AIx) as a measure of arterial wave reflections. Circulating levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and plasminogen activator inhibitor-1 (PAI-1) were measured. RESULTS Compared with placebo, Ω-3 PUFAs treatment resulted in a significant improvement in pSm values of FMD (p<0.05), AIx (p<0.001) and PWV (p<0.01). Although, acute cigarette smoking decreased FMD and caused an increase in AIx and PWV, Ω-3 PUFAs treatment blunted the acute smoking-induced impairment of FMD (p<0.001), AIx (p<0.05) and PWV (p<0.05) and significantly decreased levels of TNFα (p<0.05) and IL-6 (p=0.01) and increased levels of PAI-1 (p=0.05). CONCLUSIONS Ω-3 PUFAs improved endothelial function and the elastic properties of the arterial tree in healthy smokers, with a parallel anti-inflammatory effect.

The role of microRNAs in coronary artery disease: From pathophysiology to diagnosis and treatment

MicroRNAs (miRNAs) are tiny non-coding RNA molecules that regulate gene expression predominantly at the post-transcriptional level. Far from being simple intracellular regulators, miRNAs have recently been involved in intercellular communication and have been shown to circulate in the bloodstream in stable forms. In the past years specific miRNA expression patterns have been linked to the development of atherosclerosis and coronary artery disease, two closely related conditions. The study of miRNAs has promoted our understanding of the processes involved in the pathogenesis of atherosclerosis and innovative diagnostic and therapeutic approaches have emerged. In this review, we present the role of miRNAs in the development of atherosclerosis, on coronary artery disease progression and we assess their role as diagnostic biomarkers. Finally we evaluate the therapeutic and preventive opportunities that arise from the study of miRNAs in coronary artery disease and especially in myocardial infarction.

Dose-dependent effects of short term atorvastatin treatment on arterial wall properties and on indices of left ventricular remodeling in ischemic heart failure

OBJECTIVES Statins, beyond their lipid lowering role, exert beneficial effect on endothelial function in patients with atherosclerosis. Aim of the present study was to examine the short term pleiotropic effects of different doses of atorvastatin treatment, on endothelial function, arterial stiffness and indices of left ventricular remodeling in heart failure (HF) patients. METHODS We studied the effect of 4 weeks administration of atorvastatin in 22 patients with ischemic HF. The study was carried out on two separate arms, one with atorvastatin 40 mg/d and one with atorvastatin 10 mg/d (randomized, double-blind, cross-over design). Endothelial function was evaluated by flow mediated dilation (FMD) in the brachial artery and arterial stiffness by augmentation index (AIx). Serum levels of matrix metalloproteinase-9 (MMP-9) and intracellular adhesion molecule-1 (sICAM-1) were measured as biomarkers of left ventricular remodeling and endothelial function, respectively, while, b-type natriuretic peptide (BNP) was measured as a marker of left ventricular function. RESULTS Compared to baseline, atorvastatin 40 mg/d significantly improved FMD values (3.18 ± 3.03% vs. 5.98 ± 2.49%, p = 0.001) and AIx values (25.98 ± 8.55% vs. 23.09 ± 8.87%, p = 0.046). In addition, compared to baseline measurements, treatment with atorvastatin 40 mg/d resulted in significantly decreased levels of serum logMMP-9 levels (2.47 ± 0.23 ng/ml vs. 2.39 ± 0.24 ng/ml, p = 0.04) and of logICAM-1 levels (2.46 ± 0.13 ng/ml vs. 2.37 ± 0.16 ng/ml, p < 0.001). No significant changes were found after treatment with atorvastatin 10 mg/d in the aforementioned parameters. CONCLUSIONS Short term treatment with 40 mg/d of atorvastatin exerts beneficial impact on arterial wall properties and on indices of left ventricle remodeling in heart failure patients.

Favorable Effects of Concord Grape Juice on Endothelial Function and Arterial Stiffness in Healthy Smokers

BACKGROUND Smoking is associated with impaired vascular function. Concord grape juice (CGJ), a rich source of flavonoids, can modify cardiovascular risk factors. Endothelial function and arterial stiffness are surrogate markers of arterial health. We examined the impact of CGJ on arterial wall properties in healthy smokers. METHODS We studied the effect of a 2-week oral treatment with CGJ in 26 healthy smokers on 3 occasions (day 0 (baseline), day 7, and day 14) in a randomized, placebo-controlled, double-blind, crossover study. Measurements were taken before (pSm), immediately after (Sm0), and 20 minutes after (Sm20) cigarette smoking. Endothelial function was evaluated by flow-mediated dilation (FMD) of the brachial artery. Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness. RESULTS Compared with placebo, treatment with CGJ resulted in a significant improvement in pSm values of FMD (P = 0.02) and PWV (P = 0.04). At baseline, smoking decreased FMD in both the CGJ group (P < 0.001) and the placebo group (P < 0.001). Compared with placebo, CGJ treatment prevented the acute smoking-induced decrease in FMD on day 7 (P = 0.02) and day 14 (P < 0.001). Moreover, at baseline, smoking induced a significant elevation in PWV in both the CGJ group (P = 0.02) and the placebo group (P = 0.04). Treatment with CGJ prevented the smoking-induced elevation in PWV on day 7 (P = 0.003) and day 14 (P < 0.001). CONCLUSIONS CGJ consumption improved endothelial function and vascular elastic properties of the arterial tree in healthy smokers and attenuated acute smoking-induced impairment of arterial wall properties.

Adiponectin and cardiovascular disease: mechanisms and new therapeutic approaches.

Adiponectin is an abundant plasma protein secreted from adipocytes. Its role in energy homeostasis is well-known, including the regulation of hydrocarbons and lipids metabolism as well as the improvement of insulin resistance. It has been thought to be a key molecule in the development of type 2 diabetes mellitus and metabolic syndrome, which are epidemiological targets for preventing cardiovascular disease. In addition to beneficial metabolic effects, adiponectin seems to have anti-inflammatory, anti-atherosclerotic and vasoprotective actions. Furthermore, adiponectin affects signalling in myocardial cells and exerts beneficial actions on the heart after pressure overload and ischemia-reperfusion injury. The ability of adiponectin to reduce insulin resistance in conjunction with its antiinflammatory and cardioprotective properties makes this adipocytokine a promising therapeutic target. On clinical interest, agents that enhance endogenous adiponectin production or action have potential for the treatment of cardiovascular disease. Management strategies that increase adiponectin levels include weight reduction, Mediterranean diet, thiazolidinediones, antihypertensive and lipid lowering drugs. Current knowledge on the main actions of adiponectin and therapeutic approaches for cardiovascular disease is summarized in this review.

Oxidative Stress and Early Atherosclerosis: Novel Antioxidant Treatment

Atherosclerotic lesions initiate in regions characterized by low shear stress and reduced activity of endothelial atheroprotective molecules such as nitric oxide, which is the key molecule managing vascular homeostasis. The generation of reactive oxygen species from the vascular endothelium is strongly related to various enzymes, such as xanthine oxidase, endothelial nitric oxide synthase and nicotinamide-adenine dinucleotide phosphate oxidase. Several pharmaceutical agents, including angiotensin converting enzyme inhibitors, angiotensin receptors blockers and statins, along with a variety of other agents, have demonstrated additional antioxidant properties beyond their principal role. Reports regarding the antioxidant role of vitamins present controversial results, especially those based on large scale studies. In addition, there is growing interest on the role of dietary flavonoids and their potential to improve endothelial function by modifying the oxidative stress status. However, the vascular-protective role of flavonoids and especially their antioxidant properties are still under investigation. Indeed, further research is required to establish the impact of the proposed new therapeutic strategies in atherosclerosis.