An increase or decrease in blood pressure (BP) during middle age can significantly affect the lifetime risk for cardiovascular disease (CVD), coronary heart disease (CHD), and stroke, according to a new study.

Researchers at Northwestern University (Chicago, IL, USA) collected and pooled data from seven diverse US cohort studies to estimate the lifetime risk (LTR) for CVD, CHD, and stroke; estimates for white and black men and women with death free of CVD were used as a competing event. LTR for CVD by BP strata and by changes in BP over an average of 14 years were estimated, starting at age 55, in 61,585 men and women for a total of 700,000 person-years. The researchers continued to follow the patients until the occurrence of a first CV event, death, or age 95.

The results showed that the overall LTR for CVD was 52.5% for men and 39.9% for women; the risks for coronary heart disease were 30.9% and 17.5%, and the risks for stroke were 11.2% and 14.7%, respectively. Those who maintained or decreased their BP to normal levels had the lowest remaining LTR for CVD (22%-41%), as compared to individuals who had or developed hypertension by the age of 55 (42%-69%). The lifetime risk for CVD was higher among Blacks compared with Whites of the same sex, and increased with rising BP at middle age; almost 70% of the men who developed high BP in middle age experienced a CVD event by age 85. The study was published in the December 20, 2011, issue of Circulation.

“Taking blood pressure changes into account can provide more accurate estimates for lifetime risk of cardiovascular disease, and it can help us predict individualized risk, and thus, individualized prevention strategies,” said lead author Norrina Allen, PhD, an assistant professor in the department of preventive medicine. “Both avoiding hypertension during middle age or delaying the onset of the development of hypertension appear to have a significant impact on an individual's remaining lifetime risk for CVD.”

“Since the data suggests that both early elevations and changes over time in blood pressure measurements impact the future risk of CVD, people can take preventive steps early on to reduce their chances of heart attack or stroke,” added coauthor Donald Lloyd-Jones, MD. “Maintaining a healthy diet, combined with exercise and weight control, can help reduce blood pressure levels and, consequently, your risk for CVD later in life.”

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