Department of Food and Nutritional Sciences, University of Reading, Reading, UK.
Mol Nutr Food Res. 2012 Jun;56(6):966-75. doi: 10.1002/mnfr.201100726.
Evidence for the benefits of green tea catechins on vascular function is inconsistent, with genotype potentially contributing to the heterogeneity in response. Here, the impact of the catechol-O-methyltransferase (COMT) genotype on vascular function and blood pressure (BP) after green tea extract ingestion are reported.
Fifty subjects (n = 25 of the proposed low-activity [AA] and of the high-activity [GG] COMT rs4680 genotype), completed a randomized, double-blind, crossover study. Peripheral arterial tonometry, digital volume pulse (DVP), and BP were assessed at baseline and 90 min after 1.06 g of green tea extract or placebo. A 5.5 h and subsequent 18.5 h urine collection was performed to assess green tea catechin excretion. A genotype × treatment interaction was observed for DVP reflection index (p = 0.014), with green tea extract in the AA COMT group attenuating the increase observed with placebo. A tendency for a greater increase in diastolic BP was evident at 90 min after the green tea extract compared to placebo (p = 0.07). A genotypic effect was observed for urinary methylated epigallocatechin during the first 5.5 h, with the GG COMT group demonstrating a greater concentration (p = 0.049).
Differences in small vessel tone according to COMT genotype were evident after acute green tea extract.
关于绿茶儿茶素对血管功能益处的证据并不一致，基因分型可能导致反应的异质性。在这里，报告了儿茶酚-O-甲基转移酶（COMT）基因型对绿茶提取物摄入后血管功能和血压（BP）的影响。
50 名受试者（n = 25 名拟低活性[AA]和高活性[GG] COMT rs4680 基因型）完成了一项随机、双盲、交叉研究。在基线和摄入 1.06 克绿茶提取物或安慰剂后 90 分钟时评估外周动脉张力、数字体积脉搏（DVP）和血压。进行了 5.5 小时和随后的 18.5 小时尿液收集，以评估绿茶儿茶素的排泄。DVP 反射指数观察到基因型与处理的相互作用（p = 0.014），AA COMT 组的绿茶提取物减弱了安慰剂观察到的增加。与安慰剂相比，摄入绿茶提取物后 90 分钟时舒张压的增加趋势更为明显（p = 0.07）。在最初的 5.5 小时内，尿甲基化表没食子儿茶素的基因型效应明显，GG COMT 组的浓度更高（p = 0.049）。
根据 COMT 基因型，急性绿茶提取物后小血管张力的差异明显。
