MILWAUKEE (MCT) — What can a person's daytime napping habits, a woman's mammogram or migraine headaches tell them about their risk of having a stroke?

Possibly, quite a bit.

New research findings have pinpointed the seemingly unrelated measures as possible clues to stroke risk.

One of the more surprising studies involves a condition known as benign arterial calcifications, a fairly routine, nonmalignant finding that can show up on a mammogram.

Physicians had considered these calcifications harmless, but over the last several years a number of studies have suggested that they might be signs of an increased risk of heart disease and diabetes.

A recent retrospective analysis now finds a significant association between the condition and stroke in women, especially women ages 40 to 60.

The study looked at mammograms of 204 women ages 40 to 90 who later suffered a stroke. It compared those with a baseline group of mammograms from other women who did not have heart disease or diabetes.

Analysis showed a high correlation between having benign arterial calcification and stroke risk.

For women ages 40 to 50, the risk was 13 times greater. For ages 50 to 60, the risk was eight times. From 60 to 70, the risk was 4.5 times. For those over the age of 70, the risk was about three times greater.

"What do we do about this?" said study co-author Paul Dale, chief of surgical oncology at the University of Missouri School of Medicine. "Up to now, we've done nothing."

Dale said the research suggests that when calcium deposits are found in the blood vessels of the breast it may be a sign of calcification of the arteries supplying blood to the brain.

"We know it occurs in heart disease," he said.

With tens of millions of mammograms being done every year in the U.S., doctors say the research presents a potential new way to use the tests, said Jeffrey Binder, a neurologist who practices at Froedtert Hospital in Wauwatosa, Wis.

A finding of calcification, especially in women under 60, should warrant additional checks for stroke risk factors such as high cholesterol, high blood pressure and diabetes, said Binder, a professor of neurology at the Medical College of Wisconsin.

In some cases, it might even be advisable to order an ultrasound imaging test of the carotid artery, he said.

"I would definitely get the cholesterol checked," Binder said.

Arvind Ahuja, a neurosurgeon and co-director of the stroke center at Aurora St. Luke's Medical Center in Milwaukee, said he planned to share the study with other doctors at the hospital so there can be follow-up when calcification is found on mammograms.

"It's beautiful that you can start to pick up the risk on the mammogram," he said. "(The mammogram) can serve two purposes."

He said it makes sense that calcification in the arteries of the breast may be a sign of calcifications in the heart or brain.

The mammogram study was presented recently at an American Stroke Association conference.

Another study presented at the meeting found a strong correlation between stroke risk and whether a person dozed off during the day.

The study involved 2,153 Hispanics, blacks and whites with an average age of 73 who were followed for an average of 2.3 years.

The researchers used a sleep scale to determine levels of unintentional sleeping such as during a conversation with someone, while sitting quietly after lunch and while stopped briefly in traffic.

Those who reported "some dozing" were 2.6 times more likely to have a stroke than those who reported no dozing. For those who reported "significant dozing," the risk was 4.5 times greater.

"We saw something very striking in a short period of time," said lead author Bernadette Boden-Albala, an assistant professor of neurology at Columbia University's College of Physicians and Surgeons.

The study also found a connection between dozing and the risk of a heart attack or some other form of vascular death.

It was 1.6 times higher in moderate dozers and 2.6 times higher in significant dozers.

Earlier research has showed a link between sleep apnea, which often causes daytime sleepiness, and heart disease and stroke.

In still another potential unconventional risk factor for stroke, researchers established a link in women who have migraine headaches.

The study involved 28,000 female health professionals age 45 and older who were part of the ongoing Women's Health Study.

The study found that women who had migraines at least weekly were 2.7 times more likely to have a stroke and 49 percent more likely to have a heart attack than women who never had migraines.

Nearly all the increased risk was in those who had migraine preceded by a visual disturbance called an "aura."

But while apnea may explain part of the association between the dozing and stroke, there likely are other factors, said senior author Ralph Sacco, professor and chairman of neurology at the University of Miami Miller School of Medicine.

The dozing could be an indicator of depression and anxiety or it might be due to some other sleep disturbance, Sacco said.

Researchers must still figure out whether the dozing is caused by sleep disturbances, he said.

In still another potential unconventional risk factor for stroke, researchers established a link in women who have migraine headaches.

The study involved 28,000 female health professionals age 45 and older who were part of the ongoing Women's Health Study.

The study found that women who had migraines at least weekly were 2.7 times more likely to have a stroke and 49 percent more likely to have a heart attack than women who never had migraines.

Nearly all the increased risk was in those who had migraine preceded by a visual disturbance called an "aura."

Surprisingly, women who had migraines less than once a month also were at increased risk. Compared with those who never had a migraine, they were 64 percent more likely to have a heart attack and 45 percent more likely to have a stroke. Nearly all that risk was in those who had migraine with aura.

The study, by researchers at the Harvard School of Public Health, was presented at the American Academy of Neurology annual meeting last month. The research did not show whether the increased risk was because of the migraine or something else, such as drugs used to treat the headaches or some other factor.