Arciero P J, Gardner A W, Benowitz N L, Poehlman E T
Human Performance Laboratory, Skidmore College, Saratoga Springs, New York 12866-1632, USA.
Eur J Clin Nutr. 1998 Nov;52(11):805-12. doi: 10.1038/sj.ejcn.1600651.
To examine age-related differences in blood pressure, heart rate, behavioral mood state and norepinephrine kinetics after caffeine ingestion in younger and older men.
Placebo-controlled, double-blind study.
General Clinical Research Center, University of Vermont.
10 older (O) (65-80 y) and 10 younger (Y) (19-26 y) healthy men who were moderate consumers of caffeine (Y= 126+/-30 mg/d; O = 160 44 mg/d:NS; mean +/- s.e.m.).
All volunteers were characterized for fasting plasma glucose, insulin and caffeine levels, body composition, anthropometry, physical activity, and energy intake. Before and after placebo and caffeine ingestion (5 mg/kg fat-free mass) test days, the following variables were measured in all subjects: heart rate, blood pressure, mood state, and norepinephrine concentrations (NEconc), appearance (NEapp) and clearance (NEcl).
Systolic and diastolic blood pressure, heart rate, mood state, and norepinephrine kinetic responses to placebo and caffeine ingestion.
Following caffeine ingestion, plasma caffeine levels were similar in Y and O men. Systolic (SBP) and diastolic (DBP) blood pressure increased significantly (P < 0.01) from baseline by 9% (130+/-6 vs 142+/-6 mmHg) and 3% (75+/-3 vs 77+/-3 mmHg), respectively, in O men following caffeine ingestion, but remained unchanged in Y men. Self-reported feelings of tension (P < 0.05) and anger (P = 0.06) decreased in O men, while anger tended to increase in Y men (P < 0.06) following caffeine ingestion. Heart rates in both groups were unaltered following caffeine ingestion. No differences were noted at baseline between O and Y men for NEconc, NEapp and NEcl. After caffeine ingestion, NEconc were significantly greater in O than Y men, whereas NEapp and NEcl rates did not differ from baseline in either group. Blood pressure and subjective mood state effects of caffeine were not related to changes in norepinephrine kinetics.
Age may play a role in augmenting blood pressure response and reducing subjective feelings of anger and tension following caffeine ingestion, suggesting that the elderly are more reactive to the pressor and less sensitive to the subjective effects of the drug. These effects do not appear to be mediated by changes in sympathetic nervous system activity.
研究年轻男性和老年男性摄入咖啡因后血压、心率、行为情绪状态及去甲肾上腺素动力学的年龄相关差异。
安慰剂对照、双盲研究。
佛蒙特大学综合临床研究中心。
10名老年（O组）（65 - 80岁）和10名年轻（Y组）（19 - 26岁）健康男性，均为适度咖啡因消费者（Y组 = 126±30毫克/天；O组 = 160±44毫克/天：无显著差异；均值±标准误）。
所有志愿者均测定空腹血糖、胰岛素和咖啡因水平、身体成分、人体测量学指标、身体活动及能量摄入。在服用安慰剂和咖啡因（5毫克/千克去脂体重）前后的测试日，测量所有受试者的以下变量：心率、血压、情绪状态以及去甲肾上腺素浓度（NEconc）、表观量（NEapp）和清除率（NEcl）。
收缩压和舒张压、心率、情绪状态以及对安慰剂和咖啡因摄入的去甲肾上腺素动力学反应。
摄入咖啡因后，Y组和O组男性的血浆咖啡因水平相似。摄入咖啡因后，O组男性的收缩压（SBP）和舒张压（DBP）较基线分别显著升高（P < 0.01）9%（130±6对142±6毫米汞柱）和3%（75±3对77±3毫米汞柱），而Y组男性则无变化。摄入咖啡因后，O组男性自我报告的紧张感（P < 0.05）和愤怒感（P = 0.06）降低，而Y组男性的愤怒感有增加趋势（P < 0.06）。两组摄入咖啡因后心率均未改变。O组和Y组男性在基线时的NEconc、NEapp和NEcl无差异。摄入咖啡因后，O组男性的NEconc显著高于Y组男性，而两组的NEapp和NEcl率与基线相比均无差异。咖啡因对血压和主观情绪状态的影响与去甲肾上腺素动力学变化无关。
年龄可能在增强咖啡因摄入后的血压反应以及减轻愤怒和紧张主观感受方面起作用，这表明老年人对咖啡因的升压作用更敏感，而对其主观效应较不敏感。这些效应似乎并非由交感神经系统活动的变化介导。
