Institute for Ageing and Health, Newcastle University, Stroke Research Group, Level 6, Leazes Wing, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP, UK.
Hypertension. 2013 Jun;61(6):1309-15. doi: 10.1161/HYPERTENSIONAHA.112.200972. Epub 2013 Mar 25.
Hypertension is associated with reduced cerebral blood flow (CBF). Intensive (<130/80 mm Hg) blood pressure (BP) lowering in older people might give greater reduction in cardiovascular risk, but there are concerns that this might produce hypoperfusion which may precipitate falls and possibly stroke. We determined the effect of intensive compared with usual BP lowering on CBF in hypertensive older subjects. Individuals aged >70 years with a history of systolic hypertension on 1 or no BP lowering drugs were recruited from primary care (n=37; age, 75±4 years; systolic BP, >150 mm Hg) and randomized to receive intensive (target BP, <130/80 mm Hg) or usual (target BP, <140/85 mm Hg) BP lowering for 12 weeks, with reviews every 2 weeks. CBF, determined using 3T arterial spin labeling MRI, and 24-hour ambulatory BP were performed at baseline and after 12 weeks of treatment. Baseline BP (ambulatory or in clinic) and baseline gray matter CBF were not significantly different between the groups. After treatment, BP was reduced significantly in both groups but fell more in the intensive group (26/17 versus 15/5 mm Hg; P<0.01). Over the same period, gray matter CBF increased significantly in the intensive group (7±11 mL/min per 100 g; P=0.013) but was unchanged in the usual BP target group (-3±9 mL/min per 100 g; P=0.23); P<0.01 for comparison. Intensive BP lowering in older people with hypertension increases CBF, compared with BP lowering to usual target. These findings suggest hypertension in older people shifts the autoregulatory CBF curve rightward and downward and is reversible with BP lowering.
高血压与脑血流（CBF）减少有关。在老年人中进行强化（<130/80mmHg）降压治疗可能会更大程度地降低心血管风险，但人们担心这可能会导致灌注不足，从而导致跌倒甚至中风。我们旨在确定与通常的降压相比，强化降压对高血压老年患者 CBF 的影响。从初级保健中招募了患有收缩期高血压病史且服用 1 种或未服用降压药物的年龄>70 岁的个体（n=37；年龄，75±4 岁；收缩压，>150mmHg），并将其随机分为强化组（目标血压，<130/80mmHg）或常规组（目标血压，<140/85mmHg），降压治疗 12 周，每 2 周进行一次复查。在基线和治疗 12 周后，使用 3T 动脉自旋标记 MRI 测定 CBF，并进行 24 小时动态血压监测。在治疗前，两组的基础血压（动态或诊室血压）和基础灰质 CBF 无显著差异。治疗后，两组的血压均显著降低，但强化组降低幅度更大（26/17 与 15/5mmHg；P<0.01）。在同一时期，强化组灰质 CBF 显著增加（7±11mL/min/100g；P=0.013），而常规降压目标组无变化（-3±9mL/min/100g；P=0.23）；两组之间的差异有统计学意义（P<0.01）。与降压至常规目标相比，在高血压老年患者中进行强化降压可增加 CBF。这些发现表明，老年人高血压使自动调节 CBF 曲线向右和向下移动，并且可以通过降压来逆转。
