Dipartimento di Medicina Interna, Malattie Cardiovascolari e NefroUrologiche; Facoltà di Medicina, University of Palermo, Palermo, Italy.
Eur J Clin Nutr. 2010 May;64(5):483-9. doi: 10.1038/ejcn.2010.9. Epub 2010 Feb 3.
BACKGROUND/OBJECTIVES: Coffee is the most widely consumed beverage in the world, but its effect on the cardiovascular system has not been fully understood. Coffee contains caffeine and antioxidants, which may influence endothelial function, both of which have not yet been investigated. The objective of this study was to investigate the acute effects of coffee on endothelial function measured by brachial artery flow-mediated dilation (FMD).
SUBJECTS/METHODS: A total of 20 (10 males and 10 females) healthy non-obese subjects underwent a double-blind, crossover study. Subjects ingested one cup of caffeinated (CC) and one cup of decaffeinated (DC) Italian espresso coffee in random order at 5- to 7-day intervals.
Following CC ingestion, FMD decreased progressively and significantly (mean+/-s.e.m.: 0 min, 7.7+/-0.6; 30 min, 6.3+/-0.7; 60 min, 6.0+/-0.8%; ANOVA (analysis of variance), P<0.05), but it did not significantly increase after DC ingestion (0 min, 6.9+/-0.6; 30 min, 8.1+/-0.9; 60 min, 8.5+/-0.9%; P=0.115). Similarly, CC significantly increased both systolic and diastolic blood pressure; this effect was not observed after DC ingestion. Blood glucose concentrations remained unchanged after ingestion of both CC and DC, but insulin (0 min, 15.8+/-0.9; 60 min, 15.0+/-0.8 muU/ml; P<0.05) and C-peptide (0 min, 1.25+/-0.09; 60 min, 1.18+/-0.09 ng/ml; P<0.01) blood concentrations decreased significantly only after CC ingestion.
CC acutely induced unfavorable cardiovascular effects, especially on endothelial function. In the fasting state, insulin secretion is also likely reduced after CC ingestion. Future studies will determine whether CC has detrimental clinically relevant effects, especially in unhealthy subjects.
背景/目的：咖啡是世界上最广泛饮用的饮料，但它对心血管系统的影响尚未被完全了解。咖啡含有咖啡因和抗氧化剂，这两者可能影响内皮功能，目前都还没有被研究过。本研究的目的是通过肱动脉血流介导的扩张（FMD）来研究咖啡对内皮功能的急性影响。
受试者/方法：共有 20 名（10 名男性和 10 名女性）健康非肥胖受试者进行了一项双盲、交叉研究。受试者以 5-7 天的间隔随机摄入一杯含咖啡因（CC）和一杯脱咖啡因（DC）的意大利浓咖啡。
CC 摄入后，FMD 逐渐显著下降（均值+/-标准误：0 分钟，7.7+/-0.6；30 分钟，6.3+/-0.7；60 分钟，6.0+/-0.8%；方差分析（ANOVA），P<0.05），但 DC 摄入后 FMD 没有显著增加（0 分钟，6.9+/-0.6；30 分钟，8.1+/-0.9；60 分钟，8.5+/-0.9%；P=0.115）。同样，CC 显著增加了收缩压和舒张压；这种效应在 DC 摄入后没有观察到。CC 和 DC 摄入后血糖浓度保持不变，但胰岛素（0 分钟，15.8+/-0.9；60 分钟，15.0+/-0.8 muU/ml；P<0.05）和 C 肽（0 分钟，1.25+/-0.09；60 分钟，1.18+/-0.09 ng/ml；P<0.01）的血液浓度在 CC 摄入后显著降低。
CC 急性引起不利的心血管效应，特别是对内皮功能。在禁食状态下，CC 摄入后胰岛素分泌也可能减少。未来的研究将确定 CC 是否具有有害的临床相关影响，特别是在不健康的受试者中。
