Castellani Sergio, Bacci Marzia, Ungar Andrea, Prati Patrizio, Di Serio Claudia, Geppetti Pierangelo, Masotti Giulio, Neri Serneri Gian Gastone, Gensini Gian Franco
Institute of Internal Medicine and Cardiology, Department of Critical Care Medicine and Surgery, University of Florence, and Azienda Ospedaliera-Universitaria Careggi, Florence, Italy.
Hypertension. 2006 Dec;48(6):1143-50. doi: 10.1161/01.HYP.0000248533.58693.c4. Epub 2006 Oct 23.
The aim of this study was to investigate the cerebrovascular adaptability to 2 sequential pressor stimuli in elderly patients with isolated systolic hypertension. Ten healthy elderly normotensive subjects (68 to 82 years), 10 elderly subjects with isolated systolic hypertension (63 to 82 years), and 10 young normotensive subjects (24 to 40 years) took part in the study. A pressor reaction, using sequential cold pressor and handgrip stimulation, was induced. The cerebrovascular response to the pressor stimulation was measured by transcranial Doppler determination of the mean flow velocity in the middle cerebral arteries. In all of the subjects, blood pressure increased during handgrip (+12 mm Hg, P<0.001 in the young; +18 mm Hg, P<0.01 in the elderly normotensive subjects; +19 mm Hg, P<0.001 in the hypertensive patients versus baseline). In the hypertensive subjects, the pressure increase persisted well into the recovery period. The pressure increase caused a significant increase in mean flow velocity in the middle cerebral arteries only in the elderly subjects. Cold pressor test increased blood pressure in all of the subjects during stimulation and the first 2 minutes of the recovery period (at whole-curve ANOVA: F=22.03, P<0.001 in the young participants; F=18.3, P<0.001 in the normotensive elderly; and F=13.04, P<0.001 in the hypertensive elderly). Mean flow velocity in the middle cerebral arteries significantly increased only in the hypertensive subjects. In the elderly hypertensive patients, the cerebrovascular reaction to adrenergic stimuli was more impaired than in the elderly normotensive subjects. This event can amplify the pressure insult on cerebral hemodynamics and increase the predisposition to cerebral damage, such as vascular cognitive impairment or stroke.
本研究旨在调查单纯收缩期高血压老年患者脑血管对连续两次升压刺激的适应性。10名健康老年血压正常受试者（68至82岁）、10名老年单纯收缩期高血压受试者（63至82岁）和10名年轻血压正常受试者（24至40岁）参与了该研究。通过连续冷加压和握力刺激诱导升压反应。通过经颅多普勒测定大脑中动脉平均流速来测量脑血管对升压刺激的反应。在所有受试者中，握力时血压升高（年轻受试者升高12 mmHg，P<0.001；老年血压正常受试者升高18 mmHg，P<0.01；高血压患者升高19 mmHg，P<0.001，与基线相比）。在高血压受试者中，血压升高在恢复期仍持续存在。血压升高仅在老年受试者中导致大脑中动脉平均流速显著增加。冷加压试验在刺激期间及恢复期的前2分钟使所有受试者血压升高（全曲线方差分析：年轻参与者F=22.03，P<0.001；血压正常的老年人F=18.3，P<0.001；高血压老年人F=13.04，P<0.001）。大脑中动脉平均流速仅在高血压受试者中显著增加。在老年高血压患者中，脑血管对肾上腺素能刺激的反应比老年血压正常受试者受损更严重。这一情况可放大对脑血流动力学的压力损伤，并增加发生脑损伤的易感性，如血管性认知障碍或中风。
