Prospective Study of Coronary Heart Disease Incidence in Relation to Fasting Total Homocysteine, Related Genetic Polymorphisms, and B Vitamins

Abstract

Background—Elevated plasma total homocysteine (tHcy), low B-vitamin intake, and genetic polymorphisms related to tHcy metabolism may play roles in coronary heart disease (CHD). More prospective studies are needed. Methods and Results—We used a prospective case-cohort design to determine whether tHcy-related factors are associated with incidence of CHD over an average of 3.3 years of follow-up in a biracial sample of middle-aged men and women. Age-, race-, and field center–adjusted CHD incidence was associated positively (P<0.05) with tHcy in women but not men, and CHD was associated negatively (P<0.05) with plasma folate (women only), plasma pyridoxal 5′-phosphate (both sexes), and vitamin supplementation (women only). However, after accounting for other risk factors, only plasma pyridoxal 5′-phosphate was associated with CHD incidence; the relative risk for the highest versus lowest quintile of pyridoxal 5′-phosphate was 0.28 (95% CI=0.1 to 0.7). There was no association of CHD with the C677T mutation of...