Association of serum antioxidants and risk of coronary heart disease in South Indian population

BACKGROUND AND AIM: Higher prevalence of coronary heart disease (CHD) has been reported in south Indian population, which cannot be accounted for by the traditional risk factors like hyperlipidemia. Identification of new risk factors may help in treatment and prevention of CHD in this part of the world. In an attempt to investigate the causes of increased incidence of CHD in this part of the world, we intended to look for oxidative stress in our patients as a possible risk factor. As an initial step in this perspective, a case- control study was conducted to find out the serum antioxidant levels and their association with CHD in south Indian population.
SETTINGS AND DESIGN: A tertiary care hospital; Case - control study.
MATERIALS AND METHODS: One hundred thirty nine angiographically proven CHD patients (aged 29-75 years) were studied against 59 population based healthy controls (aged 29-72 years) free of CHD. Fasting serum cholesterol, triglycerides, HDL cholesterol, erythrocyte and plasma glutathione peroxidase and superoxide dismutase were estimated on automated clinical chemistry analyzer. LDL cholesterol and VLDL cholesterol were calculated. Vitamins A and E were estimated using high performance liquid chromatography (HPLC).
STATISTICAL ANALYSIS: Unpaired t test was used to compare means. Binary logistic regression was done to find out the association between dependent and independent variables.
RESULTS: Significantly higher levels of Total Cholesterol/HDL cholesterol and LDL cholesterol/HDL cholesterol ratio and lower HDL cholesterol levels were observed in patients when compared to controls. No significant difference of plasma and erythrocyte glutathione peroxidase and superoxide dismutase activity was observed between patients and controls. Significantly lower levels of vitamin E in patients than in controls was observed (P<0.001). Serum vitamin E was inversely associated with coronary heart disease even after controlling for age and other coronary risk factors (Odds ratio 0.898, 95% CI 0.826-0.976 P=0.01).
CONCLUSIONS: The results of present study suggest that deficiency of vitamin E may be an independent risk factor of CHD. This study brings out the need for long- term monitoring of vitamin E supplementation as a preventive measure for CHD in the population studied.

Keywords
Coronary heart disease, Lipids, Lipoproteins, Antioxidants, South India