Importance of total homocysteine levels as a risk factor for atherosclerosis

In our study, fasting plasma levels of total homocysteine, cysteine and cysteinilglycine, and fasting serum levels of folic acid, vitamine B12, total cholesterol, HDL-cholestrol, LDL-cholesterol, VLDL, triglyceride, total protein, albumin and creatinine were mesured in 68 cases with coronary heart disease and in 42 control subjects with no history of coronary heart disease or atherosclerosis. Changes in the levels of total thiol compounds depends on sex, age, menopausal status, alcohol intake, cigarette smoking were evaluated. Also we studied, the correlation between the levels of total thiol compounds consist of homocysteine, cysteine and cysteinilglycine and folic acid, vitamin B12 and other measured parameters in both cases and controls. The mean plasma homocysteine and cysteine values in the patient and control groups were 16.32±0.64 |aM, 254.61 ±8.09 |iM and 9.23±0.70 \M, 187.1 ±7.68 ixM, respectively. Differences observed for homocysteine and cysteine between cases and controls were statistically significant but non significant for cysteinilglycine. Highly significant positive correlations were observed between the levels of plasma total homocysteine and cysteine, these correlations were 56% for controls and 53% for cases. There were the positive correlations between homocysteine and cysteinilglycine and between cystein and cysteinilglicine in patient group. The cases were divided in four groups consist of stable angina, unstable angina, myocard infarction and others.The highest and over normal homocysteine and cysteine levels were found in the stabile angina group whereas cysteinilglycine levels were normal in this group, otherwise the lowest homocysteine, cysteine and cysteinilglycine levels were observed in the unstabile angina group.84 However, there was no statistically significant difference among patient groups in terms of mean values of thiol compounds. We found a correlation of plasma homocystein levels with age. Because of the fact that most of patients in our study consist of postmenopausal women, no significant difference was found between women and men in terms of homocysteine, cysteine and cysteinilgliycine levels. When the levels of homocysteine and other thiol compound were evaluated depending on cigarette smoking, total thiol levels did not show any difference among the current smoker, ex-smoker and nonsmoker both in cases and controls. The levels of folic acid and vitamin B12 were in normal range in both cases and controls and, no statistically significant difference was found. When the correlations were evaluated between homocysteine, cysteine cysteinilglycine and folic acid, vitamin B12, there was no significant correlation in both cases and controls. Patients with low levels of vitamin B12 had significantly higher cysteine and cysteinilglycine levels than patients with normal levels of vitamin B12. The higher serum creatinine, triglyceride and VLDL and lower protein and albumin levels were found in patients to compared with controls, but the levels of these parameters are in the normal range.