Treatment of hyperhomocysteinemia in renal transplant recipients. A randomized, placebo-controlled trial.

<bold>Background: </bold>Stable renal transplant recipients have an excess prevalence of hyperhomocysteinemia, which is a risk factor for arteriosclerosis.<bold>Objective: </bold>To determine the effect of treatment with 1) vitamin B6 or 2) folic acid plus vitamin B12 on fasting and post-methionine-loading plasma total homocysteine levels in renal transplant recipients.<bold>Design: </bold>Block-randomized, placebo-controlled, 2 x 2 factorial study.<bold>Setting: </bold>University-affiliated transplantation program.<bold>Patients: </bold>29 clinically stable renal transplant recipients.<bold>Intervention: </bold>Patients were randomly assigned to one of four regimens: placebo (n = 8); vitamin B6, 50 mg/d (n = 7); folic acid, 5 mg/d, and vitamin B12, 0.4 mg/d (n = 7); or vitamin B6, 50 mg/d, folic acid, 5 mg/d, and vitamin B12, 0.4 mg/d (n = 7).<bold>Measurements: </bold>Fasting and 2-hour post-methionine-loading plasma total homocysteine levels.<bold>Results: </bold>Vitamin B6 treatment resulted in a 22.1% reduction in geometric-mean post-methionine-loading increases in plasma total homocysteine levels (P = 0.042), and folic acid plus vitamin B12 treatment caused a 26.2% reduction in geometric-mean fasting plasma total homocysteine levels (P = 0.027). These results occurred after adjustment for age; sex; and pretreatment levels of total homocysteine, B vitamins, and creatinine.<bold>Conclusions: </bold>Vitamin B6 should be added to the combination of folic acid and vitamin B12 for effective reduction of both post-methionine-loading and fasting plasma total homocysteine levels in renal transplant recipients. [ABSTRACT FROM AUTHOR]