A woman's heart rate at rest may help predict her risk of a heart attack, a study of postmenopausal women suggests.
It was known that higher heart rates are linked with a higher risk of heart attack in men. The study in Wednesday's online issue of the British Medical Journal shows the same appears to be true for women.
Women with resting heart rates of more than 76 beats per minute were considered to be 26 per cent more likely to have a heart attack or die from heart disease than those with heart rates of 62 beats per minute or lower.
The researchers used data on more than 129,000 postmenopausal women with no history of heart problems and made their findings during almost eight years of follow-up.
A resting heart rate measures beats per minute while sitting. The measurement is taken to get an idea of how well the heart works when it is not stressed. In the study, participants sat quietly for five minutes before their pulse was measured.
Dr. Judith Hsia, a professor at George Washington University School of Medicine and her colleagues concluded that "simple measurement of resting pulse independently predicts coronary events, but not stroke, in post-menopausal women."
The link "is less than the association with cigarette smoking or diabetes mellitus but might be large enough to be clinically meaningful and is independent of physical activity."
The relationship between resting heart rate and heart attack risk was stronger in women less than 65 years old than in women over 65, the researchers found.
The study's authors took into account factors that might affect resting heart rate, such as nervousness, depression, smoking, alcohol use, and body mass index.
Adds to risk factors
During the follow-up period, the women, who were participating in the Women's Health Initiative study, suffered 2,281 fatal or non-fatal heart attacks and 1,877 strokes.
The link with heart disease was independent of the amount of exercise taken and there was no difference between races or those with or without diabetes.
The study "adds heart rate to the numerous other risk factors known to influence the chances of having a heart attack," said Prof. Peter Weissberg, medical director of the British Heart Foundation.
"One's heart rate changes minute by minute in response to things like activity and emotion, so people shouldn't automatically assume that if their heart rate happens to be high at a particular time it is putting them at risk of a heart attack."
Lifestyle changes such as eating a low-fat diet, lower blood pressure, avoiding obesity and increasing physical activity are recommended to prevent cardiovascular problems.