Changes in Homocysteine Levels During Low Dose Methotrexate Therapy for Rheumatoid Arthritis

Chang, Ji Eun; Lee, Jisoo; Chung, Wha Soon; Lee, Mi Ae

Abstract

OBJECTIVE
To determine the effect of short term methotrexate (MTX) therapy and subsequent folic acid (FA) supplementation on plasma homocysteine (p-homocysteine) levels in patients with rheumatoid arthritis (RA).
METHODS
Sixteen RA patients treated with low dose MTX (10 mg/week) were prospectively studied for 8 weeks. Sixteen age and sex matched healthy individuals were included for control. Serial p-homocysteine levels were determined before the initiation of MTX, 4 weeks after the MTX treatment, and further 4 weeks after FA supplementation. FA and vitamin B12 levels were determined before MTX treatment.
RESULTS
Baseline p-homocysteine levels were not significantly different between the RA patients and the controls (7.63 vs 8.40micromol/L). However, in patients with RA, FA levels negatively correlated with the baseline p-homocysteine levels (p=0.009), whereas this negative correlation was not found in the controls. RA patients showed increased tendency in homocysteine levels after MTX treatment without folic acid supplementation but did not reach statistically significance (8.4 vs. 9.06micromol/L, p=0.57). With FA supplementation, the p-homocysteine levels significantly decreased to the level lower than the baseline value before treatment (8.40 vs. 7.05micromol/L, p=0.004).
CONCLUSIONS
Folic acid nutriture is an important factor in determining baseline p-homocysteine levels. Folic acid supplementation during low dose MTX therapy result in decrease in p-homocysteine level, thereby, may be helpful to decrease the cardiovascular risk in patient with RA receiving MTX.