Low circulating vitamin B-12, B-6 and folate leading to marked hyperhomocysteinemia - associations with premature cerebral and peripheral vascular disease

Background and Aim: Hyperhomocysteinemia is an independent risk factor for vascular disease; the known causes of hyperhomocysteinemia include vitamin B-6 and B-12 and folic acid deficiencies. The aim of this study was to inve stigate the possible role of hyperhomocysteinemia - with special attention to marked hyperhomocysteinemia - in the development of premature vascular d isease, and the extent to which impaired vitamin status may contribute to a bnormal homocysteine metabolism. Methods: An oral methionine loading test was performed on 43 patients aged less than 60 years, 24 of whom with cerebrovascular disease (CVD), 10 with peripheral vascular disease (PVD), and 9 with coronary heart disease (CHD), as well as on 25 healthy controls. Results: Marked hyperhomocysteinemia (defined as post load value higher tha n mean value of controls pills 3 standard deviations, corresponding to 81 m u mol/L) was found in 7 patients (4 CVD and 3 PVD) but in none of the contr ols (p<0.01). These 7 subjects, who accounted for all of the difference in Hey levels between patients and controls, had significantly lower (p<0.01) levels of vitamins B-6, B-12 and folate than did both healthy controls and vascular patients without marked hyperhomocysteinemia. Conclusions: In our study population an association has been shown between low vitamin B concentrations and premature vascular disease (cerebral and p eripheral), and this association is mediated by marked hyperhomocysteinemia , as detected by oral methionine loading. (C) 1998, Medikal Press.