Increases and decreases in blood pressure during middle age and even earlier in adulthood can significantly affect heart attack and stroke risk later in life, a new study shows.
The analysis of data from seven studies involving more than 61,000 people examined how changes in blood pressure during middle age affect lifetime risk of heart disease and stroke.
Researchers confirmed that people with normal blood pressure at age 55 had a relatively low lifetime risk for heart disease or stroke between 22 per cent and 41 per cent.
In contrast, those who had already developed high blood pressure by this age had a higher lifetime risk of between 42 per cent and 69 per cent. The findings highlight the importance of maintaining normal blood pressure throughout middle age and even earlier.
The researchers at the Northwestern University Feinberg School of Medicine note that “People who maintained a low blood pressure of less than 120 over 80 had the lowest lifetime risk for heart disease and stroke, and those who stayed above 140 over 90 had the highest.
The longer people can delay the onset of hypertension, the better off they are.
The researchers were able to estimate lifetime risk for heart attack, stroke, and other heart-related events for white and African-American adults.
Starting with a first-time reading at an average age of 41, the researchers tracked blood pressure changes until age 55 and then continued to follow the study participants until the occurrence of a heart attack, stroke, or other medically similar event, or until death or age 95.
By their mid- 50s, about one in four men and two in five women still had normal blood pressure, and about half of men and women had blood pressure that was above normal but not yet high enough to be considered high.
Women had greater increases in blood pressure during middle age than men did, and African-American men and African-American women had a higher lifetime risk for high blood pressure, heart attack, and stroke than white men and women.
Based on their analysis, the researchers predicted that:
More than two out of three (70%) men who developed high blood pressure in middle age will have a heart attack, stroke, or other such event by age 85. Half of women who develop high blood pressure by their early 40s will develop heart disease or increase their stroke risk later in life.