Tackling hypertension has cerebral autoregulatory benefits in elderly
medwireNews: Intensive blood pressure (BP) reduction in elderly patients with hypertension does not result in cerebral hypoperfusion, say UK researchers.
On the contrary, cerebral blood flow (CBF) increased more if patients were treated to a target BP of less than 130/80 mmHg than to the usual target of below 140/85 mmHg, report Gary Ford (Newcastle University) and co-workers.
"This raises the possibility that intensive BP lowering might reduce the risk of vascular cognitive impairment and dementia compared with current more conservative BP targets," they write in Hypertension.
The study involved 37 hypertensive patients who were older than 70 years and already receiving antihypertensive medication. The patients were randomly assigned to receive additional treatment to achieve BP below an intensive target (130/80 mmHg) or the usual target.
During 12 weeks of treatment the intensive-target group achieved an average 26/17 mmHg reduction in BP, whereas the reduction in the usual-target group averaged 15/5 mmHg. Both groups achieved significant reductions, but the decrease was significantly larger among patients treated to the intensive rather than usual target. Also, 24-hour ambulatory BP fell by a corresponding 12/6 and 2/1 mmHg.
Magnetic resonance imaging at baseline and after 12 weeks revealed a significant average increase in gray matter CBF of 7 mL/min per 100 g in the intensive-target group, contrasting with a nonsignificant reduction of 3 mL/min per 100 g in the usual-target group. The changes in the two groups were significantly different from each other.
In the two groups combined, the change in gray matter CBF during treatment significantly correlated with the change in BP.
"Previous work has shown hypertension shifts the autoregulatory curve rightward placing patients at risk of impaired ability to tolerate hypotension, say Ford et al. They add: "This study suggests in an older population that intensive BP lowering moves the autoregulatory curve upward and leftward with an increase in CBF."
However, they caution that they included only healthy elderly people in their study "and the results might not apply to frail older people or individuals with autonomic dysfunction."
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Eleanor McDermid, Senior medwireNews Reporter