Role of Folic Acid in Atherosclerosis After Kidney Transplant: A Double-blind, Randomized, Placebo-controlled Clinical Trial

Abstract

Objectives: We investigated the effects of folic acid supplementation on plasma total homocysteine levels and carotid intima-media thickness after kidney transplant.

Materials and Methods: Sixty patients who had undergone a kidney transplant were studied in this double-blind, randomized, placebo-controlled clinical trial. Those subjects were randomized to receive either 5 mg/d of oral folic acid or an equivalent dosage of placebo. The main outcome variables were the plasma total homocysteine level and carotid intima-media thickness (determined via B-mode sonography) at baseline and 2, 4, and 6 months after kidney transplant. We used independent and paired sample t tests for data analysis.

Results: The mean age of the patients was 40.9 ± 10 years, and 32 of those subjects (58.2%) were men. In the control group, the plasma total homocysteine levels were 19 µmol/L at baseline, 18.7 µmol/L after 2 months, 19.3 µmol/L after 4 months, and 20 µmol/L after 6 months; and the carotid intima-media thickness measurements were 0.81 mm at baseline, 0.82 mm after 2 months, 0.84 mm after 4 months, and 0.85 mm after 6 months. In the folic acid group, the plasma total homocysteine levels were 18.5 µmol/L at baseline, 4.7 µmol/L after 2 months, 12.9 µmol/L after 4 months, and 10.9 µmol/L after 6 months; and the carotid intima-media thickness measurements were 0.73 mm at baseline, 0.73 mm after 2 months, 0.72 mm after 4 months, and 0.71 mm after 6 months.

Conclusions: Folic acid supplementation reduces both the plasma total homocysteine level and carotid intima-media thickness shortly after kidney transplant.