High blood pressure in young people may be especially dangerous for women, a new study suggests. The study found that women — but not men — with moderately high blood pressure in their early 40s may be at substantially increased risk for later coronary disease and death.
In 1992, Norwegian researchers began studying 12,329 men and women, with an average age of 41. They tracked their blood pressure and heart health for an average of 16 years.
In the beginning, high blood pressure was much lower in women than in men: 25 percent of women and 35 percent of men had stage 1 hypertension, which the American Heart Association defines as a reading of 130/80 to 139/89. (A reading less than 120/80 is considered normal.) Fourteen percent of women and 31 percent of men had stage 2 hypertension, defined as 140/90 or greater. The women also had fewer risk factors for heart disease: They had lower BMIs and lower cholesterol levels, and fewer of them were smokers.
During the follow-up period, 1.4 percent of women and 5.7 percent of men were hospitalized or died of heart disease.
Compared with women who had normal blood pressure at the start of the study, women with stage 1 hypertension had more than twice the risk of heart disease. In men, this association was statistically insignificant. study in the European Journal of Preventive Cardiology, Controlled for diabetes, BMI, cholesterol, smoking and physical activity.
The authors acknowledge that the study had limitations. It was performed in a small geographical area of Norway, and the subjects were predominantly Caucasian. In addition, the researchers had no information about the use of high blood pressure treatments or cholesterol-lowering drugs during the follow-up period.
Still, “emerging evidence is that high blood pressure is worse for female hearts than for male hearts,” said lead author Dr. Ester Kringland, an internal medicine specialist at the University of Bergen in Norway, “and the risk starts with low blood pressure levels in women.”
Dr. Joyce M. On-Hsiao, assistant professor of medicine at Yale who was not involved in the work, said, “This is a well-designed study. Most of us only look at risk factors, and We never really break it down by gender. That’s the novelty of this paper – that there is a statistical difference between men and women. And if we can replicate this finding in our more diverse populations, that’s the primary prevention will change it.”
Current American Heart Association guidelines state that in otherwise healthy people, high blood pressure of up to 130/80 can usually be managed with lifestyle changes. For readings ranging from 130/80 to 139/89, the group recommends antihypertensive medications, but only for people with other heart disease risks. At 140/90 or higher, medication is indicated in almost all cases. But the guidelines make no distinction between men and women.
Dr. Kringland said a single reading, or reading with a home blood pressure monitor, is not enough to make a diagnosis. “A doctor has to take three readings, then the average of the last two. And to be diagnosed with high blood pressure, you need to go to the doctor at least twice.”
The question is still not settled whether a healthy woman reading 130/80 should be treated with antihypertensive drugs.
“In some women — those with diabetes, for example — treatment is indicated even at this stage,” Dr. Kringland said. “But in women who are otherwise healthy? We just don’t have the answer. Blood pressure drugs do have side effects, and you have to look at the risk-benefit ratio. We need more research about heart disease in women.” “