咖啡因会损害冠心病患者以及年龄匹配的对照组对体育锻炼的心肌血流反应。
Caffeine impairs myocardial blood flow response to physical exercise in patients with coronary artery disease as well as in age-matched controls.
作者信息
Namdar Mehdi, Schepis Tiziano, Koepfli Pascal, Gaemperli Oliver, Siegrist Patrick T, Grathwohl Renate, Valenta Ines, Delaloye Raphael, Klainguti Michael, Wyss Christophe A, Lüscher Thomas F, Kaufmann Philipp A
机构信息
Cardiac Imaging, University Hospital, Zurich, Switzerland.
出版信息
PLoS One. 2009 May 22;4(5):e5665. doi: 10.1371/journal.pone.0005665.
BACKGROUND
Caffeine is one of the most widely consumed pharmacologically active substances. Its acute effect on myocardial blood flow is widely unknown. Our aim was to assess the acute effect of caffeine in a dose corresponding to two cups of coffee on myocardial blood flow (MBF) in coronary artery disease (CAD).
METHODOLOGY/PRINCIPAL FINDINGS: MBF was measured with (15)O-labelled H2O and Positron Emission Tomography (PET) at rest and after supine bicycle exercise in controls (n = 15, mean age 58+/-13 years) and in CAD patients (n = 15, mean age 61+/-9 years). In the latter, regional MBF was assessed in segments subtended by stenotic and remote coronary arteries. All measurements were repeated fifty minutes after oral caffeine ingestion (200 mg). Myocardial perfusion reserve (MPR) was calculated as ratio of MBF during bicycle stress divided by MBF at rest. Resting MBF was not affected by caffeine in both groups. Exercise-induced MBF response decreased significantly after caffeine in controls (2.26+/-0.56 vs. 2.02+/-0.56, P<0.005), remote (2.40+/-0.70 vs. 1.78+/-0.46, P<0.001) and in stenotic segments (1.90+/-0.41 vs. 1.38+/-0.30, P<0.001). Caffeine decreased MPR significantly by 14% in controls (P<0.05 vs. baseline). In CAD patients MPR decreased by 18% (P<0.05 vs. baseline) in remote and by 25% in stenotic segments (P<0.01 vs. baseline).
CONCLUSIONS
We conclude that caffeine impairs exercise-induced hyperaemic MBF response in patients with CAD to a greater degree than age-matched controls.
背景
咖啡因是消费最为广泛的药理活性物质之一。其对心肌血流的急性作用尚不为人所知。我们的目的是评估相当于两杯咖啡剂量的咖啡因对冠心病（CAD）患者心肌血流（MBF）的急性影响。
方法/主要发现：在对照组（n = 15，平均年龄58±13岁）和CAD患者（n = 15，平均年龄61±9岁）中，静息状态及仰卧位自行车运动后，用（15）O标记的H2O和正电子发射断层扫描（PET）测量MBF。在后者中，对狭窄冠状动脉及其远端所对应的节段进行局部MBF评估。口服咖啡因（200毫克）50分钟后重复所有测量。心肌灌注储备（MPR）计算为自行车运动时MBF与静息时MBF之比。两组静息MBF均不受咖啡因影响。对照组中，咖啡因摄入后运动诱导的MBF反应显著降低（2.26±0.56对2.02±0.56，P<0.005），远端节段（2.40±0.70对1.78±0.46，P<0.001）和狭窄节段（1.90±0.41对1.38±0.30，P<0.001）。咖啡因使对照组MPR显著降低14%（与基线相比P<0.05）。在CAD患者中，远端节段MPR降低18%（与基线相比P<0.05），狭窄节段降低25%（与基线相比P<0.01）。
结论
我们得出结论，咖啡因对CAD患者运动诱导的充血性MBF反应的损害程度大于年龄匹配的对照组。
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