Lead author Norrina Allen, assistant professor of preventive medicine at Northwestern University Feinberg School of Medicine, said previous estimates of one's risk of cardiovascular disease were based on a single blood pressure measurement -- with the higher the blood pressure reading, the greater the risk. The new study showed a more accurate predictor is a change in blood pressure between ages 41 and 55, Allen said.
The study used data involving 61,585 participants in the Cardiovascular Lifetime Risk Pooling Project.
The study, published in the Circulation: Journal of the American Heart Association, found men and women who developed high blood pressure in middle age, or who started out with high blood pressure, had an estimated 30 percent increased risk of having a heart attack or stroke compared to those who kept their blood pressure low.
"We found the longer we can prevent hypertension or postpone it, the lower the risk for cardiovascular disease," Allen said in a statement. "Even for people with normal blood pressure, we want to make sure they keep it at that level, and it doesn't start increasing over time. There hasn't been as much of a focus on keeping it low when people are in their 40s and 50s. We've shown it's vital to start early."