Department of General Medicine, Christchurch Hospital, 2 Riccarton Ave, Private Bag 4710, Christchurch, New Zealand.
Department of Medicine, Christchurch School of Medicine, University of Otago, Dunedin, New Zealand.
Clin Auton Res. 2023 Dec;33(6):623-633. doi: 10.1007/s10286-023-00967-5. Epub 2023 Aug 20.
Habitual coffee drinking is ubiquitous and generally considered to be safe despite its transient hypertensive effect. Our purpose was to determine the role of the sympathetic nervous system in the hypertensive response.
In a single-centre crossover study, medical caregivers were studied after consumption of standard coffee (espresso), water and decaffeinated coffee (decaff) given in random order at least 1 month apart. Plasma caffeine levels, mean arterial pressure, heart rate, total peripheral resistance and muscle sympathetic activity were recorded. Baroreflex activity was assessed using burst incidence and RR interval changes to spontaneous blood pressure fluctuations.
A total of 16 subjects (mean [± standard error] age 34.4 ± 2 years; 44% female) were recruited to the study. Three agents were studied in ten subjects, and two agents were studied in six subjects. Over a 120-min period following the consumption of standard coffee, mean (± SE) plasma caffeine levels increased from 2.4 ± 0.8 to 21.0 ± 4 µmol/L and arterial pressure increased to 103 ± 1 mmHg compared to water (101 ± 1 mmHg; p = 0.066) and decaff (100 ± 1 mmHg; p = 0.016). Peripheral resistance in the same period following coffee increased to 120 ± 4% of the baseline level compared to water (107 ± 4; p = 0.01) and decaff (109 ± 4; p = 0.02). Heart rate was lower after both coffee and decaff consumption: 62 ± 1 bpm compared to water (64 bpm; p = 0.01 and p = 0.02, respectively). Cardio-vagal baroreflex activity remained stable after coffee, but sympathetic activity decreased, with burst frequency of 96 ± 3% versus water (106 ± 3%; p = 0.04) and decaff (112 ± 3%; p = 0.001) despite a fall in baroreflex activity from - 2.2 ± 0.1 to - 1.8 ± 0.1 bursts/100 beats/mmHg, compared to water (p = 0.009) and decaff (p = 0.004).
The hypertensive response to coffee is secondary to peripheral vasoconstriction but this is not mediated by increased sympathetic nerve activity. These results may explain why habitual coffee drinking is safe.
习惯性喝咖啡很普遍，尽管咖啡有短暂的升压作用，但一般仍被认为是安全的。我们的目的是确定交感神经系统在升压反应中的作用。
在一项单中心交叉研究中，在至少相隔 1 个月的时间内，以随机顺序给医护人员饮用标准咖啡（浓咖啡）、水和脱咖啡因咖啡（脱因咖啡），然后记录血浆咖啡因水平、平均动脉压、心率、总外周阻力和肌肉交感神经活动。使用突发发生率和 RR 间隔变化来评估压力反射活动对自发性血压波动的反应。
共有 16 名（平均[±标准误差]年龄 34.4 ± 2 岁；44%为女性）受试者被招募参加该研究。10 名受试者接受了三种药物研究，6 名受试者接受了两种药物研究。在饮用标准咖啡后的 120 分钟内，与水（101 ± 1mmHg）和脱咖啡因（100 ± 1mmHg）相比，血浆咖啡因水平从 2.4 ± 0.8 增加到 21.0 ± 4μmol/L，动脉压升高至 103 ± 1mmHg（p=0.066）。在此期间，咖啡引起的外周阻力增加到基线水平的 120 ± 4%，与水（107 ± 4%；p=0.01）和脱咖啡因（109 ± 4%；p=0.02）相比。与水（64 次/分钟；p=0.01 和 p=0.02）和脱咖啡因（62 次/分钟；p=0.01 和 p=0.02）相比，咖啡和脱咖啡因后心率均较低。尽管压力反射活动从-2.2 ± 0.1 降至-1.8 ± 0.1 个/100 次/mmHg，但与水（p=0.009）和脱咖啡因（p=0.004）相比，咖啡引起的心血管迷走神经反射活动仍保持稳定，但交感神经活动下降，突发频率为 96 ± 3%。
咖啡引起的高血压反应继发于外周血管收缩，但这不是通过增加交感神经活动介导的。这些结果可能解释了为什么习惯性喝咖啡是安全的。
