Blood Pressure History May Affect Brain in Old Age
Age at which you develop hypertension is key to understanding risk for memory problems, study suggests
For the study, researchers measured the blood pressure of more than 4,000 adults in middle age, aged 50 on average. All were dementia-free at that time. The men and women had blood pressure measured again, at 76 years on average. At that time, MRIs assessed any damage to small blood vessels in the brain. The researchers also tested memory and thinking skills.
It's known that the relationship between blood pressure levels at middle age and later brain problems, including dementia, is complicated, Launer said.
Blood pressure levels tend to decline with age, and also decline when people experience dementia. Launer's team decided to look at midlife blood pressure and track the effects of both high and low blood pressure on the brain.
The researchers found that those who had high blood pressure in middle age but low diastolic pressure -- the bottom of the two readings -- in later life had brain shrinkage. They scored 10 percent lower on memory tests.
Meanwhile, those without high blood pressure in midlife who had high diastolic pressure in later life were 50 percent more likely to have severe brain lesions than those with low diastolic pressures.
Diastolic pressure measures pressure in the arteries between heartbeats. Systolic pressure, the top number, measures pressure when the heart beats. Blood pressure readings at or below 120 over 80 millimeters of mercury (mm Hg) are viewed as normal.
Experts suggest treatment with medication when blood pressure reaches 140/90 mm Hg. An expert panel last year recommended looser guidelines for most people age 60-plus, suggesting medication not be prescribed until readings reach 150/90 mm Hg.
Until more research is in, Launer offers this advice to keep the heart and brain healthy: "Monitor blood pressure, exercise, control your weight and eat healthy."