Correlation Between Inflammation and Oxidative Stress in Normocholesterolemic Coronary Artery Disease Patients ‘on’ and ‘off’ Atorvastatin for Short Time Intervals

Effect of Atorvastatin and Pioglitazone on Plasma Levels of Adhesion Molecules in Non-Diabetic Patients With Hypertension or Stable Angina or Both

BACKGROUND

It was to study the effect of atorvastatin, pioglitazone and their combination on plasma levels of adhesion molecules in patients with hypertension or stable angina or both.

METHODS

It was an open-label, randomized parallel-group study. Forty-five atorvastatin-naive patients with hypertension or stable angina or both, were randomized to receive either atorvastatin (19 patients; 10 mg OD for 12 weeks) or pioglitazone (26 patients; 30 mg OD for 12 weeks). Another group of 30 patients who were already on atorvastatin were put on add-on pioglitazone therapy (pioglitazone (15 mg OD) + atorvastatin (10 mg OD) for 12 weeks). Plasma high-sensitivity C-reactive protein (hsCRP), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) levels were measured at baseline and after 12 weeks of therapy.

RESULTS

Atorvastatin monotherapy significantly reduced plasma sICAM-1, but pioglitazone monotherapy did not produce any significant effect. Addition of pioglitazone in patients already receiving atorvastatin also significantly reduced plasma sICAM-1 level. However, there was no significant change in plasma hsCRP and sVCAM-1 levels in any of the groups after 12 weeks of therapy.

CONCLUSION

There is therapeutic advantage of combining pioglitazone and atorvastatin on plasma sICAM-1 levels.

Cardiovascular effects of resveratrol and atorvastatin treatments in an H2O2-induced stress model

Oxidative stress has been implicated in the pathophysiology of several types of cardiovascular disease (CVD). Statins are widely used to inhibit the progression of atherosclerosis and reduce the incidence of CVD. Certain over-the-counter products, including resveratrol, show similar effects to statins and may thus be used in conjunction with statins for the treatment of the majority of patients with CVD. The aim of the present study was to evaluate the effects of atorvastatin, resveratrol and resveratrol + atorvastatin (R+A) pretreatment on myocardial contractions and vascular endothelial functions in the presence of H₂O₂ as an experimental model of oxidative stress in rats. Four groups were established and referred to as the control, atorvastatin, resveratrol and R+A groups. Atorvastatin (40 mg/kg, per oral) and/or resveratrol (30 mg/kg, intraperitoneal) treatments were administered for 14 days. On the 15th day, the thoracic aortas and hearts of the rats were dissected and placed into isolated organ baths. Vascular responses to cumulative doses of H₂O₂ (1×10⁻⁸–1×10⁻⁴ M H₂O₂) with and without N (G)-nitro-L-arginine methyl ester (L-NAME) incubation were measured. In addition, myocardial electrical stimulation (ES) responses to various H₂O₂ concentrations (1×10⁻⁷–1×10⁻⁵ M H₂O₂) were evaluated. In the control and atorvastatin groups, H₂O₂ application caused a significant dose-dependent decrease in the ES-induced contractions in the myocardial tissue of rats. In the resveratrol and R+A groups, H₂O₂ application did not significantly affect myocardial contraction at any dose. In all groups, incubation with L-NAME caused a significant augmentation in the H₂O₂ response, revealing that this effect was mediated via the vascular endothelium. In conclusion, pretreatment with R+A for CVD appears to be superior to pretreatment with either agent alone.

Antioxidants in food: content, measurement, significance, action, cautions, caveats, and research needs

There are a multitude of antioxidants in foods, especially in foods of plant origin. Higher intake of antioxidant-rich foods is clearly associated with better health and functional longevity. The specific agents and mechanisms responsible are not yet clear, but there is convincing evidence that including more plant-based, antioxidant-rich foods, herbs, and beverages in the diet is effective in promoting health and lowering risk of various age-related diseases. The content of some individual antioxidants, such as vitamin C, in food can be measured, but it is not feasible to attempt to measure each antioxidant separately, and methods have been developed to assess the "total antioxidant content" of foods. One of the most widely used methods is the ferric reducing/antioxidant power (FRAP) assay, which is relatively simple, quick, sensitive, and inexpensive to perform. There are many published studies that have used the FRAP assay, and these have generated a very large database of total antioxidant content of foods that can help guide food choices for increased antioxidant intake. The FRAP assay has also been used to assess the bioavailability of antioxidants in foods and to investigate the effects of growing conditions, storage, processing, and cooking method on the total antioxidant content of food. The test can be employed as a quality control check device, and to detect adulteration of food. Furthermore, in a modified form (FRASC), the assay can measure ascorbic acid content almost simultaneously with the total antioxidant content of the sample. In this chapter, basic concepts of oxidation and the role of antioxidants, as well as the types and action of different antioxidants in foods will be reviewed briefly, and the underpinning concepts and evidence for health benefits of increased intake of dietary antioxidants will be discussed, with some focus on vitamin C, and also in the context of our evolutionary development. The basic concepts and limitations of measuring "total antioxidant content" of food will be presented. The FRAP assay and the modified version FRASC will be described, and the total antioxidant content (as the FRAP value) of a range of foods will be presented. Finally, issues of bioavailability and redox balance will be discussed in relation to the biological significance and molecular action of antioxidants in foods, some caution and caveats are presented about overcoming biological barriers to absorption of antioxidant phytochemicals, and research needs to further our understanding in the important area of food, antioxidants, and health will be highlighted.

Long-term effects of nutraceuticals (berberine, red yeast rice, policosanol) in elderly hypercholesterolemic patients

INTRODUCTION

Statins are at the forefront of strategies to manage dyslipidemia, although they are not always well tolerated. At 6-7 months after the drug was supplied, discontinuation rates averaged 30%. Alternate agents to statins have been studied. Some nutraceuticals demonstrated an efficacy in reducing cholesterol concentrations. However, there are no data regarding the use of nutraceuticals in elderly dyslipidemic patients. The purpose of this study was to examine the efficacy, safety, and tolerability of a nutraceutical-based protocol in elderly hypercholesterolemic patients previously intolerant to statins.

METHODS

This study was performed as a randomized, prospective, parallel group, single-blind study. Patients were included in the study if they had high total cholesterolemia, high low-density lipoprotein cholesterol (LDL-C), >75 years of age, statin-intolerant, and were refusing other pharmaceutical treatments for hypercholesterolemia. At the baseline visit, eligible patients were randomized to either nutraceutical-combined pill (containing berberine 500 mg, policosanol 10 mg, red yeast rice 200 mg, folic acid 0.2 mg, coenzyme Q10 2.0 mg, and astaxanthin 0.5 mg) or placebo, and the first dose was dispensed. The efficacy, safety, and tolerability of the proposed treatment were fully assessed after 3, 6, and 12 months of treatment.

RESULTS

Out of 106 consecutive patients screened, 80 eligible patients were randomized to receive either nutraceutical-combined pill (40 patients) or placebo (40 patients). No patients were lost and no deaths occurred during the follow-up. There was a statistically significant reduction in total cholesterolemia (-20%), LDL-C (-31%), and insulin resistance (-10%) with nutraceutical treatment. No significant changes were detected for plasma high-density lipoprotein cholesterol (HDL-C). Furthermore, no statistical differences were found between baseline and end-study safety parameters. Medication compliance and tolerability were high.

CONCLUSION

In this study the authors have demonstrated that combined nutraceuticals significantly reduce cholesterolemia and achieved acceptable plasma LDL-C levels in elderly hypercholesterolemic patients who were previously statin-intolerant. Combined nutraceuticals is also safe and well tolerated in these patients.

The differential effect of statins on oxidative stress and endothelial function: atorvastatin versus pravastatin

BACKGROUND

Atherogenic risk in subjects with metabolic syndrome is partly mediated by increased oxidative stress and subsequent endothelial dysfunction. Clinical trials have demonstrated differences in outcomes between subjects receiving lipophilic statins (atorvastatin) compared with hydrophilic statins (pravastatin). However, whether these findings are attributable to differences in the doses administered or to nonlipid-lowering pleiotropic effects of statins on oxidative stress and vascular function remains unknown. We hypothesized that equipotent doses of these two statins will have divergent effects on markers of oxidative stress and endothelial function.

METHODS

Thirty-six subjects with hyperlipidemia and metabolic syndrome and/or diabetes were randomized in a double-blind manner to either pravastatin 80 mg or atorvastatin 10 mg daily. Oxidative stress (dROMs assay that measures lipid hydroperoxides, plasma thiobarbituric acid reactive substances [TBARS], and aminothiol levels) and brachial artery flow-mediated dilation (FMD) were measured at baseline and after 12 weeks of statin therapy.

RESULTS

Statin therapy reduced serum low-density lipoprotein cholesterol levels equally in both groups. Atorvastatin therapy was associated with a significant reduction in TBARS (P = .006) and dROMs levels (P = .02), which was not observed in subjects treated with pravastatin. Endothelial function improved with statin therapy (P = .02), but there was no difference between the statin groups.

CONCLUSION

In hyperlipidemic subjects with metabolic syndrome, atorvastatin is associated with a greater reduction in lipid markers of oxidation compared with pravastatin. Whether these effects are responsible for the outcome differences in trials comparing these agents needs further investigation.

Atorvastatin increases myocardial indices of oxidative stress in a porcine model of hypercholesterolemia and chronic ischemia

BACKGROUND/AIM

Atorvastatin has previously been shown to reduce the endogenous angiogenic response to chronic ischemia in a porcine model. One possible mechanism for this effect is reduced bioavailability of nitric oxide, a key mediator of angiogenesis, secondary to increased oxygen free radicals. We sought to determine if atorvastatin modulates oxidative stress in myocardial tissue.

METHODS

Dietary induction of hypercholesterolemia was performed over 20 weeks in Yucatan swine with treated animals receiving atorvastatin 3 mg/kg/day. Chronic myocardial ischemia was induced via surgical placement of an ameroid constrictor ring around the proximal circumflex artery at age 20 weeks, followed by tissue harvest at age 27 weeks. Myocardial levels of protein, lipid, and DNA biomarkers of oxidative stress, serum levels of 8-isoprostane, nitric oxide (NO) dependent, and independent coronary microvascular reactivity, as well as isotope-labeled microsphere myocardial perfusion analysis and histologic analysis for endothelial cell density was performed.

RESULTS

Atorvastatin treatment was associated with elevated levels of myocardial protein oxidation and lipid peroxidation. Conversely, serum oxidant stress biomarkers were not elevated. Atorvastatin treatment improved nitric oxide dependent and independent microvascular reactivity, and was associated with decreased perfusion in the ischemic myocardial territory.

CONCLUSION

Treatment with atorvastatin was associated with increased levels of myocardial tissue protein and lipid oxidative stress biomarkers and a reduced functional endogenous angiogenic response, but improved coronary microvascular reactivity. Increased oxidative stress in tissues may play a role in the reduced angiogenic response seen with atorvastatin treatment in other studies.

Oxidative stress in young subjects with acute myocardial infarction: evaluation at the initial stage and after 12 months

In 105 subjects (97 men and 8 women) aged <46 years (mean age 39.6 +/- 5.5 years), with recent acute myocardial infarction (T1), thiobarbituric acid reactive substances and total antioxidant status were determined; NO production was evaluated by measuring the nitrite and nitrate (NOx) concentration. The patients with acute myocardial infarction were subdivided according to the main risk factors, number of risk factors, and extent of coronary lesions. The evaluation was repeated after 12 months (T2). In these subjects, thiobarbituric acid reactive substances and NOx were significantly increased and total antioxidant status was significantly decreased at T1. In single risk factor, only NO metabolites were significantly lower in acute myocardial infarction subjects who smoke than in subjects who do not. Subdividing the subjects according to the number of risk factors and number of stenosed coronary vessels, there were no significant differences between the subgroups. At T2, thiobarbituric acid reactive substances and NOx were decreased and total antioxidant status was increased, but all parameters were still altered.

Use of statins and blood pressure

BACKGROUND

Markers of inflammation such as high-sensitivity C-reactive protein (CRP) were shown to be elevated in patients with hypertension. Small trials using statin therapy showed blood-pressure (BP) reductions, but it is unknown whether this association extends to larger populations. The objective of this study was to determine whether statin use was associated with better blood-pressure control in adults with hypertension and whether inflammation levels mediated this relationship.

METHODS

This was a cross-sectional study of 2584 hypertensive adults aged >or=40 years with no known cardiovascular disease from the National Health and Nutrition Examination Survey 1999-2002. Logistic regression models were calculated to determine whether there was an association between statin use and blood-pressure control. C-reactive protein was added to the full model to determine its impact on the association.

RESULTS

Compared with people not using statin medication, significantly more statin users had their blood pressure under control (52.2% v 38.0%). After adjustment for demographic factors, statin users were two times (95% confidence interval [CI], 1.46 to 2.72) more likely to have their blood pressure under control (<140/90 mm Hg) than nonusers. After further adjustment for body mass index, diabetes, smoking, exercise, low-salt diet, and antihypertensive medications, the likelihood of having blood pressure under control remained more likely among statin users (odds ratio, 1.46; 95% CI, 1.05 to 2.05). The association between statin use and lower BP was most evident among participants who used antihypertensive medication as well as statins and was unchanged with the addition of CRP to the model.

CONCLUSIONS

Statin use was associated with a BP level <140/90 mm Hg in a representative sample of US adults with hypertension. Levels of CRP did not attenuate the association. Further studies are needed to explore the effects of statin use on blood pressure and to determine how best to apply this knowledge in clinical care.

Plasma thiobarbituric acid-reactive substance levels in subclinical hypothyroidism

OBJECTIVE

The purpose of this study was to determine thiobarbituric acid-reactive substance (TBARS) levels in subclinical hypothyroidism and to examine the effect of levothyroxine replacement on TBARS levels.

SUBJECTS AND METHODS

A cohort of 28 female patients with subclinical hypothyroidism and 24 healthy controls were enrolled in this study. The levels of plasma TBARS, serum lipids, and high-sensitive C-reactive protein (CRP) in patients with subclinical hypothyroidism at baseline and after achieving euthyroid state by levothyroxine were assessed.

RESULTS

TBARS levels of the patients were similar to those of the control group in the subclinical hypothyroid state and after restoration of euthyroidism by levothyroxine replacement. TBARS levels decreased after levothyroxine treatment, but did not reach statistical significance. There was no significant correlation between TBARS, lipid and CRP levels. Serum CRP levels were higher in subclinical hypothyroidism (4.28 +/- 0.9 mg/l) than in the control group (1.95 +/- 0.34 mg/l) and the difference was statistically significant (p = 0.03). After achieving euthyroid state, CRP levels decreased significantly in patients with subclinical hypothyroidism from 4.28 +/- 0.9 to 2.32 +/- 0.6 mg/l (p = 0.006).

CONCLUSION

Our findings suggest that there is no significant alteration of plasma TBARS levels neither in subclinical hypothyroid state nor after achieving euthyroid state. Serum CRP level is higher in patients with subclinical hypothyroidism than in the control group. Normalization of thyroid state seems to effectively reduce serum CRP levels in subclinical hypothyroidism without any correlation with TBARS activity.