RELATIONSHIP BETWEEN PLASMA HOMOCYSTEINE, VITAMIN STATUS AND EXTRACRANIAL CAROTID-ARTERY STENOSIS IN THE FRAMINGHAM-STUDY POPULATION

Recent studies demonstrated associations between occlusive vascular di sease and hyperhomocysteinemia of both genetic and nutritional origin. In the present study we analyzed plasma samples from the 20th biannua l examination of the Framingham Heart Study cohort to determine distri bution of plasma homocysteine concentrations with emphasis on relation ships to B vitamins and prevalence of carotid artery stenosis. Results showed that homocysteine exhibited strong inverse association with pl asma folate and weaker associations with plasma vitamin B-12 and pyrid oxal-5'-phosphate (PLP). Homocysteine was also inversely associated wi th intakes of folate and vitamin B-6, but not vitamin B-12. prevalence of high homocysteine (>14 mu mol/l) was 29.3% in this cohort, and ina dequate plasma concentrations of one or more B vitamins appear to cont ribute to 67% of the cases of high homocysteine, Prevalence of stenosi s greater than or equal to 25% was 43% in men and 34% in women with an odds ratio of 2.0 for individuals in the highest homocysteine quartil e (greater than or equal to 14.4 mu mol/l) compared with those in the lowest quartile (less than or equal to 9.1 mu mol/l), after adjustment for sex, age, high density lipoprotein cholesterol, systolic blood pr essure and cigarette smoking (P-trend < 0.001). plasma concentrations of folate and pyridoxal-5'-phosphate and folate intake were inversely associated with extracranial carotid stenosis after adjustment for age , sex and other risk factors.