Conrad K A, Blanchard J, Trang J M
J Am Geriatr Soc. 1982 Apr;30(4):267-72. doi: 10.1111/j.1532-5415.1982.tb07100.x.
Ten healthy elderly male volunteers were given 4 mg/kg of caffeine by intravenous infusion on three separate occasions. This resulted in mean peak plasma concentrations of caffeine of 7.4 +/- 0.7 micrograms/ml. Immediately after each of the three caffeine infusions, the mean systolic blood pressures increased 14, 7, and 16 mm Hg, and the mean diastolic blood pressures increased 7, 4, and 7 mm Hg, respectively. Both the systolic and the diastolic blood pressures returned to preinfusion values within 4 hours. The QS2 index and the left ventricular ejection time (LVET) index increased after caffeine, probably as a result of the caffeine-induced increase in arterial blood pressure. The pre-ejection period (PEP), the PEP/LVET ratio, and the diastolic time remained unchanged. Caffeine, in doses equal to those contained in 2 to 3 cups of coffee, produces an increase in blood pressure but has no demonstrable positive inotropic effect in healthy elderly men.
十名健康老年男性志愿者在三个不同时间分别接受了4毫克/千克咖啡因的静脉输注。这导致咖啡因的平均血浆峰值浓度为7.4±0.7微克/毫升。在三次咖啡因输注的每次之后，平均收缩压分别升高了14、7和16毫米汞柱，平均舒张压分别升高了7、4和7毫米汞柱。收缩压和舒张压在4小时内均恢复到输注前的值。咖啡因输注后，QS2指数和左心室射血时间（LVET）指数升高，这可能是咖啡因引起动脉血压升高的结果。射血前期（PEP）、PEP/LVET比值和舒张期时间保持不变。与2至3杯咖啡中所含剂量相当的咖啡因会使血压升高，但对健康老年男性没有明显的正性肌力作用。
