Small Increases in Blood Pressure Raise Heart Death Risk
Jan. 5, 2000 (Atlanta) -- Risk of death from heart disease is high for people whose blood pressure goes up -- even people not usually thought to be at risk. The finding, published in this week's The New England Journal of Medicine, comes from a 25-year, seven-country study showing that, at all blood-pressure levels, small increases in blood pressure greatly increase the risk that a person will die of heart disease.
In an editorial accompanying the study, Stephen MacMahon, PhD, MPH, says the study findings mean that there should be major changes in the way doctors manage blood-pressure-related diseases such as stroke and heart failure. The biggest change, he argues, is that people with high blood pressure -- a condition known as hypertension -- are far from the only people at risk of dying.
"These data from the 'Seven Countries' study now indicate without a shadow of a doubt that an individual's level of blood pressure is a major indicator of his or her risk of coronary heart disease," MacMahon, of the University of Sydney, Australia, tells WebMD. "It's not just hypertensive people, but the whole community."
The study regularly measured the blood pressure of more than 12,000 men 40-59 years old. The men were grouped into six populations: the U.S., northern Europe, Mediterranean southern Europe, inland southern Europe, rural Serbia, and Japan. None of the men had heart problems at the beginning of the study, but during the 25-year study nearly 1,300 died of heart disease.
At the same level of blood pressure, Peggy C.W. van den Hoogen, MSc, and co-workers found, U.S. and northern European men were more than three times as likely to die of heart disease as men in Japan and Mediterranean southern Europe. But when the researchers examined the effect of small increases in blood pressure, they found the same 28% increased risk of death for all populations.
"We found there is a large difference in the risk of death from coronary heart disease between men in different parts of the world," van den Hoogen tells WebMD. "Independent of baseline [that is, the beginning] blood pressure level, a given increase in blood-pressure level means a certain increase of risk."