Title of Thesis

Biochemical Studies of Homocysteine and B Vitamins in Coronary Artery Disease

Author(s)

Saatea Iftikhar

Abstract
In this study the level of serum homocysteine, vitamin B₆, Vitamin B₁₂ and folic acid and possible correlation of homocysteine with each of these vitamins was determined in the patients with first attack of acute myocardial infarction and in the patients of previous myocardial infarction. The patients were also assessed for four important risk factors of smoking, hypertension, hypercholesterolemia and physical inactivity, and their homocysteine levels were compared with the control subjects.
The study involved two hundred patients each of acute myocardial infarction and previous myocardial infarction, studied in two age groups of twenty five to forty five years and forty six to seventy years, and an equal number of age, sex and socio economically matched healthy control subjects. Fasting venous blood was obtained from the subjects. Serum homocysteine was analyzed by Fluorescence Polarization Immunoassay (FPIA) method on automated Immunoassay analyzer (Abbott IMX). The determination of B vitamins was done on HPLC (High Performance Liquid Chromatography.
Number of patients showing moderate hyperhomoeysteinemia (61.5%) as well as intermediate hyperhomocysteinemia (22%) were highest in the patients of acute myocardial infarction as compared to the patients of previous myocardial infarction and control subjects. Higher than normal homocysteine levels were recorded with increasing age and by male subjects as compared to females. Serum homocysteine showed an inverse correlation with all the three B vitamins.
Scrum vitamin B₆ levels among the patients were significantly low in the younger male patients of acute myocardial infarction as compared to other subjects, serum vitamin B₁₂ in older age patients of both diseases and serum folic acid in older patients of all groups but more significantly in the female patients of both diseases. Unexpectedly a good percentage of our apparently healthy control subjects also showed low levels of these vitamins, however this percentage was less as compared to patients.
Among the risk factors, current smokers showed highest levels of serum homocysteine followed by physically inactive persons. Hypertensive and hypercholesterolemic subjects also showed moderate hyperhomocysteincmia but these risk factors were less strongly related to acute and previous myocardial infarction than smoking and physical inactivity.
Our findings indicate that substantial nutritional deficiencies of vitamin B₆, B₁₂ and folic acid are highly prevalent in our population which together with other cardiovascular risk factors may play a role in the causation of acute and subsequent cardiovascular events.

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