The relation of serum vitamins C and E levels and the severity of angiographically defined coronary artery disease in Alsader Teaching Hospital in Basrah

Objective: To assess the relationship between the serum concentrations of vitamins C & E and the severity of coronary artery disease. Subjects and methods: In a case-control study, we evaluated 200 patients who underwent coronary angiography at AL-Basrah Cardiac Center at Al-Sader Teaching Hospital, Basra, Iraq. They were separated into two groups of case (patients with CAD) and control (non CAD). Four milliliters of blood samples were taken for measuring vitamin E and C. For statistical analyses, chi-square test, Student’s t-test, one-way ANOVA, and the logistic regression were


INTRODUCTION
oronary Artery Disease (CAD) is the chief cause of mortality and morbidity in most countries. [1][5] The principal cause of CAD is atherosclerosis [6] which is a chronic immunoinflammatory, fibroproliferative disease of large and medium-sized arteries fuelled by lipid.[9] According to the theory of oxidative stress, atherosclerosis is the result of the oxidative modification of low density lipoproteins (LDL) in the arterial wall by reactive oxygen species (ROS).Evidence suggests that traditional risk factors for atherosclerosis increase the risk of the production of free ROS, not only from the endothelial cells, but also from the smooth muscle cells and the adventitial cells. [10]itamin E is an antioxidant that acts as a scavenger for molecular oxygen and free radicals, [11] the major biologic role of tocopherol is to protect polyunsaturated fatty acids (PUFAs) and other components of cell membranes and LDL from oxidation by free radicals.It is mostly effective in avoiding lipid peroxidation. [12,13]Both in vitro and in vivo studies have established that α-tocopherol inhibits LDL oxidation and decreases the release of reactive oxygen species. [14]As an antioxidant, vitamin C chief role is to neutralize free radicals.Since ascorbic acid is water soluble, it can work both inside and outside the cells to defeat free radical damages.Free radicals look for an electron pair to regain their stability.Vitamin C is a good source of electrons so it can donate electrons to free radicals such as hydroxyl and superoxide radicals and quench their reactivity. [15]Vitamin C has a maintaining effect on vitamin E so that it is reduced by vitamin C after neutralizing the radicals by vitamin E. Therefore, it increases the potential of vitamin E in a biologic environment.Vitamin C is the leading defense system against oxidative stress. [13]To further investigate the hypothesis of a link between the oxidative stress and cardiovascular disease we analyze the serum levels of vitamin C, E, as an indicator of antioxidant system in CAD patients and comparing the differences of serum vitamins concentrations according to the number of diseased vessels as criterion for the severity of the disease.

SUBJECTS AND METHODS
This study was conducted as case control and worked at Basra Medical College in Department of Biochemistry on ninety four patients (who attended AL-Basra Cardiac Center at Al-Sader Teaching Hospital, seeking for coronary angiography) with age ranged from 37 to 86 years old in whom coronary angiography revealed that they have > 50% stenosis in one or more coronary arteries.One hundred and six patients from the same center their age range from 29 to 80 years old consider to be a control group with a normal coronary angiogram.Coronary artery disease patients were divided into three groups (single vessel disease, two vessel disease and three vessel disease) according to the number of their obstructed coronary arteries as a marker for the disease severity. [16]The medical history and the results of angiograms were taken through special questionnaire.Approximately four milliliters of venous blood samples were obtained from both control individuals and patients with CAD.Both groups have sedentary life style and there was a significant statistical difference in smoking behavior between them (P-value < 0.05) with CAD patients being more smoker than the contrary group.There is a significant higher prevalence of diabetes mellitus and hypertension in patients than control group (Pvalue < 0.05).The differences in systolic and diastolic blood pressure was statically significant (P-value < 0.05) being high in patients group.In logistic regression analysis, serum vitamin C and E ware significantly associated with CAD (OR = 0.8, 95% CI = 0.68-0.92,P = 0.0001) and (OR = 0.66, 95% CI = 0.578-0.754,while differ from a study done by Cebi et al. [18] This high prevalence of traditional risk factor ensure their role in the developments of CAD.Serum vitamins E and C remain statically significant after adjustment for other risk factors with logistic regression (Table -5).[20][21] However, other researchers (Frki, et al (2000) [22] and (Tavallaie, et al (2012) [23] found that there was no statistical difference in the level of vitamin E between CAD and non CAD patients.This low vitamin E could be due to over consumption of antioxidants or low dietary intake.Our results emphasize a negative relation between vitamin E level and the number of stenosed coronary arteries (Table -6).This result in agreement with study on Iranian population [20] while similar to study were done in Turkey. [19]This finding ensure the antioxidant role of vitamin E in atherosclerosis.The current study revealed a highly significant decrease in the serum level of ascorbic acid in CAD positive patients as compared with CAD negative patients (Table-4), this results also consistent with that of other studies [19,20,24] while inconsistent with other. [25]he possible causes behind low vitamin C maybe due to over consumption as antioxidants, over used in regeneration of vitamin E also may be due to low dietary intake.Vitamin C had negatively correlated with the severity of the disease as shown in (Table-6) this result was agreed with other reports, [19,26] this meaningful result revealed that as vitamin C become low the oxidative stress become worse and the disease become more severe.

Table 1 . Demographic and clinical characteristics of the study population
The separated serum were used for the assessment of serum vitamin C by Colorimetric method, vitamin E by ELISA kit, causabio, China.Statistical analyses was done by chi-square test, Student's t-test, one-way ANOVA test, and the logistic regression.most of them in their sixth and seventh decade of life (mean age (59.25±10.73)years), 71.2% of them are males, compared with 106 of CAD free patients and there is no statistical difference between them and CAD patients (P > 0.05) in terms of age, sex, weight, height, BMI, family history of both diabetes and hypertension.

Table 2 . Drug administration in the study population
*Values expressed by n(%).

Table 4 . Biochemical parameters in the study population.
*