Arya Atherosclerosis
Volume:2 Issue: 4, Winter 2007

Atherosclerosis and cardiovascular diseases are the most common causes of death in western countries. The beneficial effect of ascorbic acid on various organs has been reported. The present study was conducted to determine the effect of ascorbic acid on the right and left coronary arteries of male rabbits fed with high-cholesterol diet. Twenty white male rabbits (mean weight: 950 g) were weighed and randomly divided into two groups. For 40 days, group 1 (n=10) was given a high-cholesterol (1%) diet, group 2 (n=10) was fed with a high-cholesterol diet and ascorbic acid (100 mg/kg). Then both of the groups were weighed and the animals were sacrificed. The right and left coronary arteries were dissected and then fixation, tissue processing, histological sectioning and H & E staining were carried out and sections were studied by light microscopy. The results were analyzed by using the Mann Whitney test. Group 2 which received ascorbic acid had no fatty streaks in their coronary arteries. Significant difference in mean weight was observed before and after the diet in both groups (P<0.05). Histopathological study of the coronary arteries showed that the rabbits which received ascorbic acid diet did not develop fatty streaks. Thus ascorbic acid exerts an apparently inhibitory effect on fatty streak formation and may slow down or prevent atherosclerosis by countering the side effects of a high-fat meal.

Hypercholesterolemia is one of the major risk factors for atherosclerosis which is characterized by endothelial dysfunction. This study was designed to investigate the effect of aspirin on serum vascular endothelial growth factor (VEGF) and nitric oxide (NO) concentrations in hypercholesterolemic animals. Sixteen male rabbits were randomly divided into two groups, aspirin-treated and control. Aspirin (10 mg/kg/day) was administered orally using feeding tube. All animals were fed with high-cholesterol diet (1%) during the experiment. After five weeks, blood pressure, serum lipid and lipoprotein profiles, serum VEGF and NO concentrations were measured. Aspirin did not change blood pressure. Aspirin significantly decreased serum LDL (1276±72.1 vs. 1505±68.03 mg/dl) and triglyceride (477.5±8.3 vs. 649.1±15.2 mg/dl) (P<0.05). High-cholesterol diet significantly decreased serum VEGF level in both groups (control: 24.59±0.42 vs. 38.09±2.49 pg/ml; aspirin: 24.72±0.84 vs. 42.29±2.03 pg/ml) (P<0.05) and aspirin did not change serum VEGF level in hypercholesterolemic animals (P>0.05). Serum NO concentration was also significantly decreased after five weeks of high-cholesterol diet (control: 5.87±0.33 vs. 8.67±0.68 μmol/lit; aspirin: 5.66±0.33 vs. 8.58±0.60 μmol/lit) (P<0.05). Aspirin did not change serum NO level (P>0.05). We conclude that under the conditions of this study, aspirin cannot change serum VEGF and NO concentrations in high-cholesterol fed animals.

The role of obesity in diabetes mellitus, hyperlipidemia, colon cancer, sudden death and other cardiovascular diseases has been confirmed by many studies. In this study, it was hypothesized that obesity is an independent risk factor for lipid peroxidation and decreased activity of cytoprotective enzymes in humans.To test the study hypothesis, we assessed lipid peroxidation by measuring the concentrations of plasma malondialdehyde (MDA) and the activity of erythrocyte copper-zinc superoxide dismutase (CuZn-SOD), glutathione peroxidase (GPX) and catalase (CAT) in 25 obese women (BMI=30-40 Kg/m2) and 25 women with healthy BMI (19-25Kg/m2).The concentration of plasma MDA was significantly higher (P<0.001) in obese women (3.4± 0.7 µmol/L) compared to women with healthy BMI (1.4± 0.3 µmol/L). Furthermore, there was a significantly positive correlation (r =0.75, P<0.0001) between BMI and plasma MDA. On the other hand, women with healthy BMI had significantly higher (P<0.001) erythrocyte CuZn-SOD (873± 52 U/g Hb) and GPX (64.7± 14.2 U/g Hb) activity than obese women (660± 39 U/g Hb) and (48.5± 13.1 U/g Hb), respectively. Furthermore, erythrocyte CuZn-SOD and GPX activity were negatively correlated with BMI (r =-0.52, P<0.0001 and r =-0.42, P<0.001), respectively. No significant difference was observed between two groups in erythrocyte CAT activity.We conclude that obesity, diabetes, renal or liver disease can decrease the activity of protective antioxidants and can enhance the systemic oxidative stress even in the absence of smoking.

Most studies indicate that increased plasma homocysteine level is a risk factor for coronary artery disease. However, data concerning the role of homocysteine in young patients with acute myocardial infarction (AMI) is scanty. The aim of this study was to study the possible association between homocysteine plasma levels and early-onset AMI. This case-control study included 83 AMI patients and 83 healthy controls. Biochemical parameters were determined and homocysteine was measured by enzyme immunoassay. Multivariate logistic regression analysis was used to test the association of homocysteine with the occurrence of AMI Homocysteine concentration in patients with AMI was higher than in controls (19.54±13.3 and 15.54±8.9 µmol/l, respectively, P=0.002). Hyperhomocysteinemia was associated with early myocardial infarction (odds ratio=5.05). Hypercholesterolemia (OR=4/21), opium addiction (OR=4/78) and age (OR=1/24) also had associations with AMI.Our results showed that homocysteine levels are elevated in young patients with AMI, and hyperhomocysteinemia is associated with early myocardial infarction; hence it should be evaluated in all young patients with AMI.

Introducing a foreign body into the heart, a part of the human anatomy that symbolically represents emotions, is a major life event which may result in a change in the body image, changes in physical and emotional wellbeing and quality of life. In a descriptive study in Fall 2006, 78 out of 267 patients with implanted cardiac pacemakers (PPM) were randomly evaluated by using a quality of life questionnaire for patients published by Salud Co. Data entry and analysis were done by SPSS 11.5. Thirty-two men and 46 women with mean ages of 67.4 and 66.7 years, respectively, were included in the study. Thirty-six patients had single chamber VVIR, 15 had dual chamber VDD and 27 had dual chamber DDDR PPM implanted. Scores of physical and emotional wellbeing were grater than 75, but those of social/family and functional wellbeing were lower than 50 in the majority of patients. Except for a few questions, there was no significant difference between patients with single or dual chamber PPM in terms of quality of life (P=0.34). Quality of life of patients with PPM is good in respect of physical and emotional wellbeing. However, the results were not desirable in terms of family/social and functional wellbeing. Thus, family and social educational programs are recommended.

Obesity is associated with an increased risk of coronary heart disease. It is believed that adipose tissue inflammatory substances contribute to the pathogenesis of cardiovascular disease. To find out the metabolic benefits of weight loss in reducing cardiovascular risk, we assessed the effect of modest weight loss on plasma inflammatory markers in obese women.In a clinical trial, 42 obese women underwent a 10 week restricted diet program. Body weight, fasting glucose, insulin, total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c) and plasma inflammatory cytokines were measured at baseline and after 10 weeks.Weight, BMI, fasting blood glucose, insulin, cholesterol and triglyceride had significant reductions. No significant changes were observed in HDL-c and LDL-c concentrations. All plasma inflammatory proteins improved significantly except CRP level.Modest weight loss (≈5%) is associated with favorable changes in plasma inflammatory markers.

Environmental tobacco smoke (ETS) has been shown to have adverse health hazards for children. The objective of this study was to assess the effects of two intervention programs for controlling passive smoking in children based on their serum cotinine level. In this trial, 40 children, aged 8-12 years, who were exposed to ETS were randomly assigned to two groups of equal number. In the first the parents (group P), and in the second group the children (group C) were educated about the harmful effects of passive smoking. Children''s blood sample was taken for serum cotinine measurement before and after intervention in both groups. Data were analyzed by SPSSv13/win using paired t-test. Smoking allowed inside home decreased in both groups; however, this decrease in group C was significantly higher than in group P. Serum cotinine concentration decreased in both groups with a more prominent decrease in group C. Education of children can be an effective method for controlling passive smoking. This type of education can be effective for lifestyle change in the entire family.