Antigoni Miliou

Myocardial Redox State Predicts In-Hospital Clinical Outcome After Cardiac Surgery Effects of Short-Term Pre-Operative Statin Treatment

OBJECTIVESnThe purpose of this study was to evaluate the role of the myocardial redox state in the development of in-hospital complications after cardiac surgery and the effect of statins on the myocardial redox state.nnnBACKGROUNDnStatins improve clinical outcome after cardiac surgery, but it is unclear whether they exert their effects by modifying the myocardial redox state.nnnMETHODSnWe quantified myocardial superoxide anion (O(2)(-)) and peroxynitrite (ONOO(-)) and their enzymatic sources in samples of the right atrial appendage (RAA) from 303 patients undergoing cardiac surgery who were followed up until discharge, and in 42 patients who were randomized to receive 3-day treatment with atorvastatin 40 mg/d or placebo before surgery. The mechanisms by which atorvastatin modifies myocardial redox state were investigated in 26 RAA samples that were exposed to atorvastatin ex vivo.nnnRESULTSnAtrial O(2)(-) (derived mainly from nicotinamide adenine dinucleotide phosphate [NADPH] oxidases) and ONOO(-) were independently associated with increased risk of atrial fibrillation, the need for post-operative inotropic support, and the length of hospital stay. Pre-operative atorvastatin treatment suppressed atrial NADPH oxidase activity and myocardial O(2)(-) and ONOO(-) production. Ex vivo incubation of RAA samples with atorvastatin induced a mevalonate-reversible and Rac1-mediated inhibition of NADPH oxidase.nnnCONCLUSIONSnThere is a strong independent association between myocardial O(2)(-)/ONOO(-) and in-hospital complications after cardiac surgery. Both myocardial O(2)(-) and ONOO(-) are reduced by pre-operative statin treatment, through a Rac1-mediated suppression of NADPH oxidase activity. These findings suggest that inhibition of myocardial NADPH oxidases may contribute to the beneficial effect of statins in patients undergoing cardiac surgery. (Effects of Atorvastatin on Endothelial Function, Vascular and Myocardial Redox State in High Cardiovascular Risk Patients; NCT01013103).

Effects of rosuvastatin and allopurinol on circulating endothelial progenitor cells in patients with congestive heart failure: the impact of inflammatory process and oxidative stress.

OBJECTIVEnEndothelial progenitor cells (EPCs) contribute to the maintenance of endothelial integrity and function. We investigated the effects of rosuvastatin and allopurinol on the number of EPCs in patients with heart failure and aimed to provide insight into the molecular inflammatory and oxidative mechanisms that could be responsible for the alterations in EPC levels after treatment.nnnMETHODSnSixty patients with systolic heart failure were randomized to receive rosuvastatin 10mg/d, allopurinol 300mg/d or placebo and followed up for 1 month. The number of CD34(+)/KDR(+) and CD34(+)/CD133(+)/KDR(+) EPCs in blood was evaluated by flow cytometry. Endothelial function was assessed by brachial artery flow-mediated dilation. Levels of markers of inflammation and oxidative stress were also determined.nnnRESULTSnCirculating EPCs were significantly increased after rosuvastatin treatment (from 230 (170-380) and 10 (8-24) to 390 (230-520) and 19 (8-33) cells/10(6) lymphomonocytes, respectively, p=0.004 and p=0.008), whereas they remained unchanged in the other groups. The increase in EPC levels was not associated with the changes in the levels of the measured inflammatory and oxidative markers.nnnCONCLUSIONnShort-term treatment with rosuvastatin, but not allopurinol, significantly increases the number of circulating EPCs in patients with heart failure providing further insights into its role in these individuals. The impact of rosuvastatin on EPCs is not mediated by changes in inflammatory and oxidative status.

Effects of rosuvastatin on myeloperoxidase levels in patients with chronic heart failure: A randomized placebo-controlled study

BACKGROUNDnStudies indicate that myeloperoxidase (MPO) is associated with disease progression and severity in heart failure (HF), while it may provide a mechanistic link between inflammation and adverse cardiac remodeling. The mechanisms that regulate MPO are unclear, while it is unknown whether specific treatments such as HMG-CoA reductase inhibitors and xanthine oxidase inhibitors may modify MPO. Therefore in the present study we examined the effects of rosuvastatin and allopurinol on MPO levels in patients HF.nnnMETHODSnSixty clinically stable patients with systolic HF were randomized to receive rosuvastatin 10mg/day, allopurinol 300mg/day or placebo and followed up for 1 month. Plasma levels of MPO and serum levels of soluble CD40 ligand, interleukin-6, and oxidized LDL were determined using ELISA. All measurements were made before and after 1-month treatment.nnnRESULTSnRosuvastatin significantly reduced plasma levels of MPO (p=0.003), which remained unchanged in the other groups. Furthermore, the change of MPO levels in the rosuvastatin-treated group was significantly different compared with the other groups (p<0.05). Rosuvastatin administration also led to a significant decrease in oxidized LDL (p=0.009), while the other inflammatory markers remained unchanged in all groups. In the total population, a significant correlation was observed between the baseline levels of MPO and hsCRP (r=0.275, p=0.027), fibrinogen (r=0.278, p=0.025), and sCD40L (r=0.288, p=0.021).nnnCONCLUSIONSnShort-term treatment with rosuvastatin regulates inflammatory process in patients with heart failure by significantly reducing plasma levels of MPO. This finding reveals a novel pleiotropic effect of statins in patients with heart failure, and provides further insights into the pathophysiological mechanisms of MPO in heart failure.

Acute effects of different types of oil consumption on endothelial function, oxidative stress status and vascular inflammation in healthy volunteers.

Consumption of different types of oil may have different effects on cardiovascular risk. The exact role of maize oil, cod liver oil, soya oil and extra virgin olive oil on endothelial function, oxidative stress and inflammation is unknown. We evaluated the effect of acute consumption of these types of oil on endothelial function, oxidative stress and inflammation in healthy adults. Thirty-seven healthy volunteers were randomised to receive an oral amount of each type of oil or water. Endothelial function was evaluated by gauge-strain plethysmography at baseline and 1, 2 and 3 h after consumption. Oxidative stress status was determined by total lipid peroxides (PEROX), while inflammatory process was estimated by measuring the soluble form of vascular adhesion molecule 1. Serum levels of the two previous markers were measured at baseline and 3 h after oil consumption. Reactive hyperaemia (RH) was significantly decreased after maize oil consumption compared with controls (P < 0.05). However, the consumption of cod liver oil and soya oil induced a significant improvement of RH after 1 h, compared with controls (P < 0.05). There was no significant effect of any type of oil consumption on endothelium-independent dilatation, total lipid PEROX and vascular adhesion molecule 1 serum levels. Consumption of maize oil leads to impaired endothelial function, while soya oil and cod liver oil slightly improve endothelial function. However, all types of oils did not affect inflammatory process and systemic oxidative stress, suggesting that their effect on endothelial function may not be mediated by free radicals bioavailability.

Exercise duration as a determinant of vascular function and antioxidant balance in patients with coronary artery disease

Background Exercise improves the clinical outcome of patients with coronary artery disease (CAD); however, the ideal exercise duration for each patient remains unclear. Objective To investigate the effects of exercise duration on arterial elastic properties and antioxidant/pro-oxidant mechanisms in patients with CAD. Design, setting, patients, interventions Sixty male patients with CAD were randomised into two groups, and underwent exercise for 30 min or 60 min in a crossover design with 2 weeks wash-out period. In all participants aortic and radial blood pressures (BP) and arterial elastic properties (augmentation index (AIx)/pulse wave velocity (PWV)) were determined at baseline and 24 h after exercise. Plasma malonyldialdehyde (MDA) and superoxide dismutase (SOD)1 and SOD2 levels were also measured. Results Exercise had no effect on aortic and radial BP (p=NS for all). Walking for 30min improved AIx (from 33.79±0.91% to 31.73±0.86%, p<0.001) and PWV (from 9.26±0.95m/s to 9.06± 0.21m/s, p<0.001), while exercise for 60min had adverse effects on vascular stiffness (for AIx: from 33.37± 0.93% to 33.73± 1.05%, p=NS and for PWV: from 9.25±0.19m/s to 9.37±0.21m/s, p<0.05 mainly in older patients). Exercise for 60min was associated with a significant 20% increase in MDA levels (p<0.05). Exercise had no effects on SOD1 levels, however it significantly increased SOD2 levels after 30min (from 2.26±0.22ng/mL to 2.36±0.18ng/mL, p<0.05) but not after 60min (p=NS). Conclusion Shorter exercise duration was associated with favourable antioxidant and vascular effects, while longer exercise blunted these beneficial effects and was accompanied by adverse effects on vascular function, mainly in older coronary patients. Further studies are required to explore the hypothesis that a more individualised approach to the selection of the appropriate exercise programme should be considered for patients with CAD.

The association of the 174G > C polymorphism of interleukin 6 gene with diabetic nephropathy in patients with type 2 diabetes mellitus

AIMSnTo evaluate the association of 174G>C polymorphism on interleukin-6 (IL-6) gene with diabetic nephropathy in patients with type 2 diabetes.nnnMETHODSnA total of 393 Greek subjects with type 2 diabetes (mean age 66.5±10.0years, men n=203, women n=190) were examined. Diabetic nephropathy was defined as presence of microalbuminuria and/or proteinuria. The IL-6 174G>C polymorphism was detected by polymerase chain reaction and appropriate restriction enzyme digestion. High sensitivity C-reactive protein was assayed by particle-enhanced immunonephelometry.nnnRESULTSnThe genotype distribution (%) was GG: 49.1, GC: 26.8 and CC: 24.1, with no gender difference. The CC homozygotes had lower albumin excretion (mg/24h) in comparison with the GC genotype [CC: 8.9 (4.0-20.9) vs GC: 21.95 (9.1-53.35), P=0.004]. Participants with the GC genotype tended to have more frequently nephropathy than those with the GG or the CC genotype [GC: 44.55% vs GG: 35.1% and CC: 28.3%, P=0.07)]. The CC homozygotes in comparison with GC heterozygotes had lower odds to have nephropathy (odds ratio: 0.51, 95% confidence intervals=0.28-0.91, P=0.02), even after adjustment for sex, age, duration of diabetes, body mass index, smoking, hypertension, lipids and glycated hemoglobin, (P=0.01).nnnCONCLUSIONnIn type 2 diabetes states, CC homozygotes have lower albumin excretion and are protected from nephropathy in comparison with GC genotypes.

Comparative effects of rosuvastatin and allopurinol on circulating levels of matrix metalloproteinases and tissue inhibitors of metalloproteinases in patients with chronic heart failure

BACKGROUNDnPatients with chronic heart failure (HF) are characterized by alterations in matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) levels. However, the impact of hypolipidemic and antioxidant treatment in MMPs and TIMPs is unknown. In the present study, we sought to compare the effects of statins and xanthine oxidase inhibitors on circulating levels of MMPs and TIMPs in patients with chronic HF.nnnMETHODSnForty-two clinically stable patients with mild to moderate HF were randomized to receive rosuvastatin 10xa0mg or allopurinol 300xa0mg daily and followed up for 1xa0month. Serum levels of MMP-2, -9, TIMP-1, and -2 were measured before and after treatment.nnnRESULTSnLevels of MMP-2 and -9 were significantly decreased in the rosuvastatin group (from 251±52xa0ng/ml and 400±206xa0ng/ml to 215±47xa0ng/ml and 309±166xa0ng/ml, p<0.001 and p<0.05 respectively), but not in the allopurinol group. In the rosuvastatin group, TIMP-2 levels were significantly increased (from 85±17xa0ng/ml to 93±16xa0ng/ml, p<0.05), while TIMP-1 remained unchanged. In the allopurinol group, no significant changes were observed regarding the levels of TIMPs.nnnCONCLUSIONSnShort-term rosuvastatin but not allopurinol administration decreases MMP-2 and -9 and increases TIMP-2 levels.

Impact of 6 weeks of treatment with low-dose metformin and atorvastatin on glucose-induced changes of endothelial function in adults with newly diagnosed type 2 diabetes mellitus: A single-blind study

BACKGROUNDnStatin treatment has been reported to improve survival in patients with atherosclerosis, partly by improving vascular endothelial function. Elevation of blood glucose concentrations impairs endothelial function and promotes atherogenesis, but the effect of statins on glucose-induced endothelial dysfunction is unknown. Endothelium-dependent dilation (EDD) measured by gauge-strain plethysmography in the forearm is considered to be a reliable marker of endothelial function in forearm resistance vessels.nnnOBJECTIVEnThis study examined the combined effects of metformin and atorvastatin treatment on glucose-induced endothelial dysfunction (as EDD) in patients with newly diagnosed type 2 diabetes mellitus (DM).nnnMETHODSnPatients with newly diagnosed DM were recruited and were randomly assigned to receive metformin 850 mg/d or metformin 850 mg/d + atorvastatin 10 mg/d for 6 weeks in a single-blind study. All patients underwent glucose loading (75 g oral glucose after 12 hours of fasting) at baseline and at the end of the treatment period. Blood samples were obtained at baseline before glucose loading and 3 hours after loading to determine serum concentrations of cholesterol, lipoproteins, triglycerides, glucose, and glycosylated hemoglobin. EDD was evaluated at baseline and at 1, 2, and 3 hours after loading. The investigators were blinded to the treatment group assignments, and all analyses were performed in a blinded manner. Adverse events (eg, gastrointestinal disorders, myopathy, liver disorders) were monitored based on reported symptoms or signs (eg, myalgias, muscle cramps), clinical examination, and laboratory parameters (eg, increased liver and muscle enzymes).nnnRESULTSnThirty-two white patients with newly diagnosed type 2 DM were randomly assigned to receive metformin 850 mg/d (n = 17 [12 men]; mean [SD] age, 53.88 [45] years; body mass index [BMI], 28.7 [4.5] kg/m²) or metformin 850 mg/d + atorvastatin 10 mg/d (n = 15 [6 men]; mean age, 52.53 [37] years; BMI, 28.5 [2.1] kg/m²). At baseline, EDD was reduced 1 and 2 hours after glucose loading in both study groups (P < 0.01). Glucose loading was associated with an elevation of blood glucose concentrations at 1 and 2 hours (P < 0.01 vs resting levels before loading), and concentrations returned to resting levels at 3 hours, in both groups at baseline and after treatment. Metformin alone or in combination with atorvastatin was associated with a significant reduction in resting glucose concentrations after 6 weeks (both, P < 0.05 vs baseline), but only the combination of metformin + atorvastatin partly prevented the glucose-induced elevation of serum glucose at 1 hour after loading and the glucose-induced decrease in EDD (both, P < 0.01 vs baseline).nnnCONCLUSIONSnGlucose loading blunted endothelial function, with a deterioration in EDD, in these patients with newly diagnosed type 2 DM. However, combined treatment with metformin and atorvastatin for 6 weeks partly prevented the glucose-induced impairment of EDD in these patients, with a significant difference compared with monotherapy with metformin.

Combined effects of fibrinogen genetic variability on atherosclerosis in patients with or without stable angina pectoris: focus on the coagulation cascade and endothelial function.

BACKGROUNDnFibrinogen is a coagulation/inflammatory biomarker strongly associated with atherogenesis. Data have reported that the genetic variability on fibrinogen chains may affect the atherosclerotic process and the risk of coronary artery disease (CAD). We examined the combined effects of the G455A and the G58A fibrinogen genetic polymorphisms on prothrombotic profile, endothelial function and the risk of CAD in a Caucasian population.nnnMETHODSnWe recruited 422 patients with angiographically documented CAD and 277 controls matched for age and gender. The two polymorphisms were genotyped by polymerase chain reaction and restriction endonuclease digestion. Fibrinogen and D-Dimers levels, as well as factors (f) V, X activity were measured by standard coagulometry techniques. Endothelial function was assessed by the flow mediated dilatation (FMD) of the brachial artery.nnnRESULTSnThe two polymorphisms had no significant effect on the risk for CAD. Although the 58AA subjects had not significantly different levels of fibrinogen compared with the 58GG+GA in both groups (p=NS), we importantly found that the 455AA homozygosity was associated with increased fibrinogen levels not only in the control group (p=0.035), but also in the CAD group (p<0.001) compared to the G allele carriers. Moreover, both the 58AA (p=0.016) and 455AA homozygotes (p=0.022) presented with higher levels of D-Dimers in the CAD group. Interestingly, the 455AA homozygotes had increased fV activity in the CAD group (p=0.048). However, no significant effects were observed on fX activity and FMD.nnnCONCLUSIONSnBoth fibrinogen polymorphisms are capable to modify the atherosclerotic process via their effects on the coagulation cascade.

Methionine-induced homocysteinemia impairs endothelial function in hypertensives: the role of asymmetrical dimethylarginine and antioxidant vitamins.

BACKGROUNDnNitric oxide synthase (NOS) inhibitor asymmetrical dimethylarginine (ADMA) is synthesized by the methylation of arginine as part of the methionine/homocysteine cycle. However, the mechanisms regulating ADMA synthesis in hypertension are unclear.nnnMETHODSnWe investigated the role of ADMA and antioxidants in endothelial dysfunction during methionine-induced homocysteinemia in hypertensives. Thirty-nine hypertensives and forty-nine normotensive controls underwent methionine loading (100 mg methionine/kg BW), after being randomized to receive vitamin C (2 g) and E (800 IU) or placebo. Endothelium-dependent dilation (EDD) was evaluated by plethysmography (baseline and 4-h post-methionine loading (4-h PML)).nnnRESULTSnHypertensives had higher homocysteine at baseline (P < 0.001) and 4-h PML (P < 0.05), whereas methionine increased homocysteine in all groups. EDD was decreased in both vitamins and placebo groups in controls (P < 0.01 for both) and vitamins- and placebo-treated hypertensives (P < 0.05 and P < 0.01, respectively). In controls, ADMA was increased in both vitamin- and placebo groups (P < 0.01 for both) at 4-h PML. Hypertensives had higher ADMA at baseline (P < 0.01 vs. normotensive) and remained unchanged at 4-h PML (P = NS in placebo and vitamins treated).nnnCONCLUSIONSnADMA is elevated in hypertensives but remains unchanged after methionine loading, suggesting that ADMA plays an important role in endothelial dysfunction in hypertensives, but it is not responsible for homocysteine-induced endothelial dysfunction in these patients.