Morgan S L, Baggott J E, Lee J Y, Alarcón G S
Department of Nutrition Sciences, School of Medicine, University of Alabama at Birmingham, USA.
J Rheumatol. 1998 Mar;25(3):441-6.
To determine the effect of longterm methotrexate (MTX) therapy and folic acid supplementation on folate nutriture and homocysteine levels in patients with rheumatoid arthritis.
A double blind, placebo controlled trial lasting one year was conducted at one academic medical center. A total of 79 patients taking low dose MTX were followed up to one year. The patients were randomized to receive placebo or 5 or 27.5 mg folic acid supplementation per week.
Plasma and erythrocyte folate levels and plasma homocysteine levels were determined. The folate nutriture of patients taking low dose MTX declined without folic acid supplementation. Plasma homocysteine levels increased significantly over a one year period in the placebo group. Low folate nutriture and hyperhomocysteinemia occurred with greater frequency in the placebo group than in the folic acid supplemented groups.
For longterm, low dose MTX therapy, there are now at least 3 reasons to consider supplementation with folic acid (a low cost prescription): (1) to prevent MTX toxicity, (2) to prevent or treat folate deficiency, and (3) to prevent hyperhomocysteinemia, considered by many investigators to be a risk factor for cardiovascular disease.
确定长期甲氨蝶呤（MTX）治疗及补充叶酸对类风湿关节炎患者叶酸营养状况和同型半胱氨酸水平的影响。
在一家学术医疗中心进行了一项为期一年的双盲、安慰剂对照试验。共有79名服用低剂量MTX的患者随访一年。患者被随机分为接受安慰剂或每周补充5或27.5毫克叶酸。
测定了血浆和红细胞叶酸水平以及血浆同型半胱氨酸水平。未补充叶酸时，服用低剂量MTX患者的叶酸营养状况下降。安慰剂组血浆同型半胱氨酸水平在一年期间显著升高。安慰剂组低叶酸营养状况和高同型半胱氨酸血症的发生率高于补充叶酸组。
对于长期低剂量MTX治疗，现在至少有3个理由考虑补充叶酸（一种低成本处方药）：（1）预防MTX毒性，（2）预防或治疗叶酸缺乏，（3）预防高同型半胱氨酸血症，许多研究者认为这是心血管疾病的一个危险因素。
