(USA TODAY) -- Younger women with coronary blockages that raise their risk for heart attacks are less likely than post-menopausal women to feel chest pain with exercise, a key warning signal for heart disease, a study suggested Wednesday.

Although women usually don't have first heart attacks until their late 60s, "we're seeing more women having heart attacks in their 40s and 50s, before menopause, because of the rise in diabetes and obesity," says Sharonne Hayes, director of Mayo Clinic's Women's Heart Clinic in Rochester, Minn.

The new study, which involved 269 women at the Montreal Heart Institute, was released at the American Psychosomatic Society meeting in Baltimore.

The women came to the facility for treadmill and heart scan tests because they had heart disease symptoms or a family history of cardiac problems, says Nadine Bekkouche, the study leader. The scans can show reduced blood flow to the heart, indicating blockage of the coronary arteries.

Women also were asked whether they experienced chest pain on the treadmill.

For the same amount of coronary blockage, post-menopausal women were nearly seven times as likely as the younger women to report pain, Bekkouche says.

If women don't feel pain, "it's even more dangerous because they can just keep pushing themselves with exercise and put their hearts under great stress," Bekkouche says.

High estrogen levels in the premenopausal women could relieve pain, Hayes speculates. Another possibility: Symptoms with menopause often make women more aware of their bodies, perhaps increasing the perception of pain in older women.

Menopause is an arbitrary cutoff; other studies indicate aging raises heart attack risk, not menopause per se, Hayes says. "Heart disease develops gradually. It starts before menopause."

The study underscores the need for women to be alert to signs of heart problems, which can be different from the symptoms men experience. Among them: pain in the chest, arm or shoulder blades; indigestion caused by exercise or by mental stress; shortness of breath; and a change in exercise tolerance.

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