The Impact of Homocysteine on Coronary Heart Disease: a look at the Most Recent Studies and Trials

Coronary Heart Disease (CHD) are leading cause of death in Bulgaria and other countries from East and Central Europe. Ecological studies show that traditional risk factors could not entirely explain the variations in population trends, suggesting need of search for new determinants of coronary risk, including homocysteine (Hcy). The results from many studies strongly suggest that plasma or serum concentration of total Hcy (tHcy) is an important marker in coronary risk assessment. Although, many data are supportive to the deteorating role of Hcy, significant discrepancies exist yet in this information. The aim of paper is to review existing data on relationship between Hcy and coronary risk, published after 1995, based on the controversial results from different types of epidemiological studies and high number of new studies conducted in the last ten years. Although many data are supportive to the adverse effect of Hcy on CHD and the relationship is consistent, strong, dose related and biologically plausible the causal role of elevated Hcy and atherosclerosis remain inconclusive. The reviewed cross-sectional and retrospective case-control studies support the association between high plasma tHcy concentration and risk of CHD. The data from prospective studies, however, suggest controversial results. The only one finished till now trail of Hcy-vitamin lowering therapy did not find a treatment effect on CHD endpoints during the two years of follow-up. The reasons for the difference in results between the prospective studies still remain unclear. Absence of population studies on Hcy in Bulgaria is an emerging circumstance for research in that field