Occasional High Blood Pressure Risky, Too?
Study Finds Episodes of High Blood Pressure, Often Ignored, Boost Stroke Risk
WebMD News Archive
Occasional High Blood Pressure Predicts Stroke continued...
The highest blood pressure readings were also associated with higher stroke
risk. Those with the highest readings over the seven visits were 15 times more
likely to have a stroke during the follow-up period.
Not all the patients were being treated for hypertension, Rothwell tells
WebMD. "Variability was predictive of stroke in both groups," he says, treated
and untreated. "Some had stable hypertension, some had episodic hypertension
and some had stable normal blood pressure. The episodic hypertension group had
the highest risk of stroke.''
In one of the studies, variability in blood pressure also predicted the risk
of heart attacks.
Blood Pressure Study Findings: Implications
The new research isn't the first to evaluate the risks of episodic high
blood pressure, Rothwell notes. Although some variability in blood pressure is
normal, the new research, he says, should inspire a change in thinking.
"I think that the risk associations, and other evidence, are sufficiently
strong for us to stop reassuring patients with variable blood pressure that
they don't have hypertension and don't need treatment, which is what current
guidelines argue if their [average] blood pressure is OK,'' Rothwell says. " We
should be concerned about episodic hypertension in patients who are not on
treatment and about residual variability in patients who are already on
Some variability is normal, he tells WebMD. How much depends on age
(typically increasing with age) and gender, with women more likely to have more
variability. African-American people, too, tend to have more variability, he
says. And other factors, such as the stiffness of the arteries, can affect the
amount of variability, he says.
For patients who have high blood pressure and take their pressure at home to
monitor it, Rothwell offers this advice based on his findings: "I think that
they should consult their doctor if the systolic blood pressure is variable,
particularly if they find that it is sometimes 150 mmHg or higher, even if it
is well controlled at other times.''
Blood Pressure Study: Second Opinion
The suspected link between episodes of high blood pressure and stroke risk
is not new, says Patrick Lyden, MD, chair of neurology at Cedars-Sinai Medical
Center in Los Angeles and a 30-year stroke researcher who reviewed the new
research for WebMD.
But the new findings, he says, are ''the most important demonstration ...
that the attacks of high blood pressure really are bad for you."
Lyden says he is aggressive about treating high blood pressure in his
patients, whether the pressure is up some time or all the time. But not all
physicians are as aggressive, he suspects. "I would say there is a widespread
practice on both continents (UK and here) that occasional high blood pressure
"This data teaches us how foolish that is," he says.
"This is still a hypothesis," Lyden tells WebMD. But "I think he's showing
us it's critically important to pay attention to this."