Stroke risk warning for people with prehypertension
MedWire News: Findings from a meta-analysis show that people with blood pressure (BP) at the high end of the "normal" range are at increased risk for having a stroke.
The effect was mainly evident among people with systolic (S)BP of 130-139 mmHg and diastolic (D)BP of 85-89 mmHg - the range classified as "high normal" in current European guidelines.
"An immediate potential implication of our findings is that young and middle-aged persons with higher systolic or diastolic blood pressure values within the prehypertensive range may benefit from relatively safe, nonpharmacologic blood pressure-lowering methods, such as reduction in salt intake and weight to reduce their risk of stroke," say the researchers.
"Nonetheless, randomized controlled trials evaluating the effect/efficacy of blood pressure reduction on reducing subsequent risk for stroke are warranted."
Bruce Ovbiagele (University of California, San Diego, USA) and team included 12 prospective cohort studies with 518,520 people in their meta-analysis. The studies all reported stroke risk in people with baseline prehypertension (SBP 120-139 mmHg, DBP 80-90 mmHg) versus normal BP, with adjustment for multiple confounders.
Overall, people with prehypertension had a significant 1.55-fold increased risk for stroke, the team reports in the journal Neurology.
Seven studies divided participants into high and low categories of prehypertension. This revealed that those with an SBP of 130-139 mmHg and a DBP of 85-89 mmHg had a 1.79-fold increased risk for stroke. By contrast, those with an SBP of 120-129 mmHg and a DBP of 80-85 mmHg had a nonsignificant 1.22-fold increase in risk.
The effect of prehypertension was consistent for men and for women, for fatal and nonfatal stroke, and for ischemic and hemorrhagic stroke.
Editorialists Amytis Towfighi (University of Southern California, Los Angeles, USA) and Gordon Kelley (Shawnee Mission Medical Center, Kansas, USA) said: "This meta-analysis raises important questions regarding how health practitioners should manage prehypertension."
They noted that lifestyle modification counseling seems to have only "modest benefits" for blood pressure, yet there is little good-quality evidence to support use of antihypertensive drugs in patients with prehypertension.
"Currently, the best treatment advice for prehypertension remains at the level of consensus expert opinion," they said.
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By Eleanor McDermid