HIGH HOMOCYSTEINE, LOW FOLATE, AND LOW VITAMIN-B-6 CONCENTRATIONS - PREVALENT RISK-FACTORS FOR VASCULAR-DISEASE IN HEART-TRANSPLANT RECIPIENTS

Background, A high plasma homocysteine concentration is a risk factor for atherosclerosis and thrombosis, which are major causes of morbidit y and mortality in heart transplant patients, High homocysteine concen trations may be caused by lower folate and vitamin B-6 levels, We hypo thesized that these patients might have high homocysteine concentratio ns and low levels of folate and vitamin B-6, which could contribute to the development of vascular complications, Methods, Total fasting pla sma homocysteine was measured in 189 cardiac transplant recipients and in healthy controls, as were concentrations of folate, vitamin B-12, vitamin B-6, and creatinine, Results, Homocysteine concentrations were higher in recipients than controls (19.1+/-13.0 vs, 11.0+/-3.0 mu mol /L, P<0.01), and hyperhomocysteinemia (>90th percentile for controls, 14.6 mu mol/L) was seen in 68% of recipients (P<0.01), Folate and vita min B-6 concentrations were lower (5.9+/-4.2 vs. 7.9+/-4.2 pmol/L and 40+/-25 vs, 84+/-77 nmol/L, respectively; P<0.01 for both), Folate and vitamin B-6 deficiencies were seen in 10.8% and 17.9% of recipients, respectively (P<0.01), Hyperhomocysteinemia was more frequent in patie nts with vascular complications after transplantation than in those wi thout (79.2% vs, 63.8%, P<0.05), Conclusions, Elevated plasma homocyst eine and deficiencies of folate and vitamin B-6 are common in transpla nt recipients. A high homocysteine concentration was more common in pa tients with vascular complications, Prospective studies are now requir ed to evaluate the role of these abnormalities as risk factors for the atherothrombotic complications of transplantation.