Coca A
Department of Internal Medicine, Hospital Clinic, School of Medicine, University of Barcelona, Spain.
J Hypertens Suppl. 1994 Jul;12(5):S13-21.
To review current knowledge on blood pressure variability.
Blood pressure variability has a time-course ranging from a few seconds or minutes (short-term variability) to 24 h (long-term variability) or 1 year (seasonal variations). The variability is influenced by physiological factors such as physical and mental activity (posture, exercise, talking) or behavioral and environmental factors (salt, caffeine, alcohol), and by pathological conditions. In patients with essential hypertension, the day-night pattern of blood pressure change is generally similar to that of normotensives, with a significant nocturnal blood pressure fall (dippers), except that the entire profile is shifted upwards. Nevertheless, in some essential hypertensives the nocturnal fall in blood pressure is absent or reversed (non-dippers), in spite of a decrease in the nocturnal heart rate. In several forms of secondary hypertension (pheochromocytoma, renal failure) and other clinical conditions (sleep apnea syndrome, diabetes mellitus, cardiac transplantation) the nocturnal fall in blood pressure is also absent or reversed.
Blood pressure variability and the blunted nocturnal fall in blood pressure may be clinically relevant. Several studies have demonstrated that subjects whose 24-h variability was higher than the group average were more likely to have target-organ damage. Moreover, hypertensive women with a blunted nocturnal fall in blood pressure (non-dippers) are more likely to suffer morbid cardiovascular events than dippers. On theoretical grounds, therefore, antihypertensive treatment that reduces blood pressure variability and preserves the nocturnal fall in blood pressure will help to protect target organs in hypertension. So far, this has not been demonstrated in clinical trials.
回顾当前关于血压变异性的知识。
血压变异性具有从几秒或几分钟（短期变异性）到24小时（长期变异性）或1年（季节性变化）的时间进程。这种变异性受生理因素如身体和精神活动（姿势、运动、交谈）或行为和环境因素（盐、咖啡因、酒精）影响，也受病理状况影响。在原发性高血压患者中，血压变化的昼夜模式通常与血压正常者相似，夜间血压显著下降（杓型），只是整体水平上移。然而，在一些原发性高血压患者中，尽管夜间心率下降，但夜间血压下降不明显或呈反向变化（非杓型）。在几种继发性高血压（嗜铬细胞瘤、肾衰竭）和其他临床状况（睡眠呼吸暂停综合征、糖尿病、心脏移植）中，夜间血压下降也不明显或呈反向变化。
血压变异性和夜间血压下降减弱可能具有临床相关性。多项研究表明，24小时变异性高于组平均水平的受试者更易发生靶器官损害。此外，夜间血压下降减弱（非杓型）的高血压女性比杓型女性更易发生心血管疾病事件。因此，从理论上讲，降低血压变异性并保持夜间血压下降的抗高血压治疗将有助于保护高血压患者的靶器官。到目前为止，这一点尚未在临床试验中得到证实。
