Bostom A G, Shemin D, Lapane K L, Hume A L, Yoburn D, Nadeau M R, Bendich A, Selhub J, Rosenberg I H
USDA Human Nutrition Research Center on Aging, Tufts New England Medical Center, Boston, Massachusetts, USA.
Kidney Int. 1996 Jan;49(1):147-52. doi: 10.1038/ki.1996.19.
Hyperhomocysteinemia, an arteriosclerotic risk factor, persists in 75% of dialysis patients despite routine low dose supplementation with the B-vitamin co-factors/substrates for homocysteine (Hcy) metabolism, and normal or supernormal plasma status of these vitamins (Atherosclerosis 114:93, 1995). We conducted a placebo-controlled eight-week trial of the effect on plasma homocysteine of adding supraphysiologic dose folic acid (15 mg/day), B-6 (100 mg/day), and B-12 (1 mg/day) to the usual daily dosing of 1 mg folic acid, 10 mg B-6, and 12 micrograms B-12, in 27 hyperhomocysteinemic dialysis patients. Total plasma homocysteine was measured at baseline, and after four and eight weeks. Blinded analyses revealed no evidence of toxicity in the group randomized to supraphysiologic dose B-vitamin supplementation. Plasma homocysteine was significantly reduced after both four weeks (-29.8% vs. -2.0%; P = 0.0024) and eight weeks (-25.8% vs. +0.6%; P = 0.0009) of active versus placebo treatment. Also, 5 of 15 treated versus 0 of 12 placebo group patients had their plasma Hcy reduced to within the normative range (< 15 mumol/liter). Supraphysiologic doses of B-vitamins may be required to correct hyperhomocysteinemia in dialysis patients.
高同型半胱氨酸血症是一种动脉粥样硬化风险因素，尽管对透析患者常规补充低剂量的B族维生素辅助因子/底物以促进同型半胱氨酸（Hcy）代谢，且这些维生素的血浆水平正常或超常，但仍有75%的透析患者存在该病症（《动脉粥样硬化》114:93，1995）。我们进行了一项为期八周的安慰剂对照试验，在27名高同型半胱氨酸血症透析患者中，于每日常规服用1毫克叶酸、10毫克维生素B6和12微克维生素B12的基础上，添加超生理剂量的叶酸（15毫克/天）、维生素B6（100毫克/天）和维生素B12（1毫克/天），观察其对血浆同型半胱氨酸水平的影响。在基线、四周和八周时测量血浆总同型半胱氨酸水平。盲法分析显示，随机接受超生理剂量B族维生素补充的组没有毒性证据。与安慰剂治疗相比，活性治疗四周后（-29.8%对-2.0%；P = 0.0024）和八周后（-25.8%对+0.6%；P = 0.0009）血浆同型半胱氨酸水平均显著降低。此外，15名接受治疗的患者中有5名血浆Hcy降至正常范围（< 15微摩尔/升），而12名安慰剂组患者中无人达到这一水平。可能需要超生理剂量的B族维生素来纠正透析患者的高同型半胱氨酸血症。
