Pettigrew Luther C, Bang Heejung, Chambless Lloyd E, Howard Virginia J, Toole James F
Department of Neurology, Stroke Program, Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY 40536-0230, United States.
Atherosclerosis. 2008 Oct;200(2):345-9. doi: 10.1016/j.atherosclerosis.2007.11.014. Epub 2007 Dec 31.
Methionine (Met) loading increases total plasma homocysteine (tHcy) and assesses homocysteine metabolism. We tested the hypothesis that pre- or post-Met tHcy will predict recurrent stroke or coronary artery disease (CAD) in a subgroup analysis of the Vitamin Intervention for Stroke Prevention (VISP) trial. VISP subjects with non-disabling stroke underwent measurement of tHcy at baseline (fasting pre- and post-Met load) and were randomized to high/low-dose B-vitamin therapy for prevention of recurrent stroke or CAD. In the sample cohort of 2124 subjects, mean+/-S.D. tHcy levels in micromol/l were pre-Met 13.2+/-4.3, post-Met 30.4+/-9.76, and pre/post-Met Delta 17.1+/-8.3. The hazard ratio (HR) for recurrent stroke was 1.16 (p=0.026) for 1 S.D. higher pre-Met tHcy and 1.15 (p=0.054) for 1 S.D. higher post-Met tHcy. For CAD, the HR for 1 S.D. higher pre-Met tHcy was 1.27 (p=0.001) and was 1.00 (p=0.99) for post-Met tHcy. In survival analyses using pre- or post-Met as covariates, the coefficient of pre/post-Met Delta was not significant for stroke and was only marginally significant for CAD (p<0.08), but was negative. We conclude that fasting, pre-Met tHcy is as effective as post-Met tHcy or pre/post-Met Delta in predicting the risk for stroke and CAD.
蛋氨酸（Met）负荷增加可使血浆总同型半胱氨酸（tHcy）升高，并可用于评估同型半胱氨酸代谢。在预防卒中的维生素干预（VISP）试验的亚组分析中，我们检验了这样一个假设：Met负荷前或负荷后的tHcy水平能够预测复发性卒中或冠状动脉疾病（CAD）。VISP试验中患有非致残性卒中的受试者在基线时（空腹状态下Met负荷前后）测量了tHcy水平，并被随机分为高/低剂量B族维生素治疗组，以预防复发性卒中和CAD。在2124名受试者的样本队列中，以微摩尔/升为单位的平均±标准差tHcy水平在Met负荷前为13.2±4.3，负荷后为30.4±9.76，负荷前后的差值为17.1±8.3。Met负荷前tHcy水平每升高1个标准差，复发性卒中的风险比（HR）为1.16（p = 0.026）；Met负荷后tHcy水平每升高1个标准差，HR为1.15（p = 0.054）。对于CAD，Met负荷前tHcy水平每升高1个标准差，HR为1.27（p = 0.001）；而Met负荷后tHcy水平对应的HR为1.00（p = 0.99）。在以Met负荷前或负荷后作为协变量的生存分析中，Met负荷前后的差值系数对卒中而言无统计学意义，对CAD仅有边缘统计学意义（p < 0.08），但为负值。我们得出结论，空腹状态下Met负荷前的tHcy在预测卒中和CAD风险方面与Met负荷后的tHcy或Met负荷前后的差值同样有效。
