TUESDAY, Jan. 1 (HealthDay News) -- People with restless legs syndrome face twice the risk of a stroke or heart disease compared to people who don't have the neurological condition, a new study suggests.

The risk is greatest in people with the most frequent and the most severe symptoms of restless legs syndrome.

"This shows that restless legs syndrome has salience beyond just symptoms," said Dr. David Rye, a professor of neurology at Emory University School of Medicine in Atlanta. "It's really saying, this disorder is salient, you need to recognize it."

Other experts added a cautionary note to the study's findings.

"This study is very well done, and the conclusions of the study are very measured. In other words, the authors acknowledge that they can't prove that what they're studying actually causes strokes or heart attacks," said Dr. Paul Greene, associate attending physician in the department of neurology at New York-Presbyterian Hospital/Columbia University Medical Center in New York City. "They also could have picked up people with other syndromes, neuropathies and things that could influence strokes and heart attacks. There are a lot of ways in which this study could be misleading.

"They will have to do something to follow up on this before pushing a panic button," he added.

Neither physician was involved with the study, which was conducted by researchers from Harvard and other institutions, and is published in the Jan. 1 issue of the journal Neurology.

Restless legs syndrome (RLS) is a neurological disorder characterized by restlessness and a need to move the legs. Symptoms start or become worse when you are resting. The symptoms occur mainly at night and can interfere with sleep. Some 5 percent to 10 percent of the adult population suffers from the syndrome, according to the study.

Earlier studies showed an association between restless legs syndrome and cardiovascular disease, but the studies had limitations. RLS has also suffered from a public image problem, which may explain why so few studies have explored the condition.

"RLS has borne the brunt of a lot of skepticism," Rye explained. "Snoring started out the same way... It took decades to convince primary-care physicians that we have to treat sleep apnea, that it's not just a nuisance that dad snores. It [sleep apnea] has a huge added risk for obesity and stroke and hypertension and cardiovascular disease."

The new study, the largest of its kind, looked at 3,433 men and women, with an average age of 68, who were enrolled in the Sleep Heart Health Study, which was originally designed to look at the cardiovascular consequences of sleep-disordered breathing.

A diagnosis of restless legs syndrome was based on a questionnaire completed by all study participants. The participants also answered questions about cardiovascular disease and stroke. Almost 7 percent of women and 3.3 percent of men in the study had restless legs syndrome.

People with the syndrome were more than twice as likely to have cardiovascular disease or stroke. The association was strongest among those who had RLS symptoms a minimum of 16 times a month and among those who said their symptoms were severe.

The study can't prove a cause-and-effect relationship, but such a link could make physiological sense. Most people with restless legs syndrome have up to 300 periodic leg movements a night, and those movements are associated with increases in blood pressure and heart rate, the study authors said.

Also, people with RLS often also suffer from sleep deprivation, which has been associated with cardiovascular disease.

"The direct data would suggest that the disrupted sleep and arousals that occur with RLS are really what's contributing to hypertension and heightened autonomic nervous system activity, which in turns leads to cardiovascular [problems]," Rye said. "But this [study] can't answer that kind of question."

The next study should look to see if treatments for restless legs syndrome reduce the risk for heart disease and stroke, Rye added. "Nobody has done that, because nobody has recognized that there was a problem," he said.

More information

To learn more, visit the Restless Legs Syndrome Foundation  .

THURSDAY, Dec. 27 (HealthDay News) -- New information about a deadly heart rhythm disorder called ventricular fibrillation may help lead to better ways of identifying people at risk of sudden cardiac death and new treatments to help reduce their risk.

The findings are based on a study by a team of researchers from Canada, Spain and the United States.

The study found that the abrupt disruption of electrical activity within the heart muscle is organized into spiral vortices -- also called rotors -- that prevent the heart's blood pumping chambers from working in sync, something that's required for normal heart function.

The researchers looked at a number of different animal species, ranging from mice and guinea pigs to sheep and humans, and found that the frequency of ventricular fibrillation activity can be "scaled" using a universal formula related to body mass. This same method can also be used to determine the size of the core of the spiral vortices, the researchers said.

"The discovery that the rate of fibrillation changes according to body size is exciting, not only because it brings new and interesting knowledge from the point of view of evolutionary biology, but most important because it erases previous concerns in science about the relevance of studies in small animals like mice to understand the most lethal cardiac arrhythmia in people," senior author Dr. Jose Jalife said in a prepared statement.

The study was published in this week's issue of the Proceedings of the National Academy of Sciences.

The scientists said these findings, made using sophisticated imaging techniques they developed, can help improve translation of ventricular fibrillation research results from animals to humans. For example, genetic variations in mice with ventricular fibrillation may also be explored in humans, and research on why VF begins, and methods of preventing it, can be studied in animals before being applied to humans, the researchers said.

More information

The American Academy of Family Physicians has more about heart rhythm problems  .

THURSDAY, Dec. 27 (HealthDay News)-- High blood levels of the fats called triglycerides are associated with an increased risk of stroke, a new study finds.

"There's a lot of evidence emerging that they have a strong effect on vascular [blood vessel] risk as a whole," said study senior author Dr. Bruce Ovbiagele, associate professor of neurology at the University of California, Los Angeles.

The study of more than 1,000 people treated for ischemic stroke -- the kind that happens when a clot blocks a blood vessel of the brain -- found that those with the highest levels of triglycerides were more than twice as likely to suffer such a stroke.

The findings are published in the Dec. 26 issue of Neurology.

Like cardiologists, neurologists concerned with the bad effects of blood fats have concentrated mostly on LDL cholesterol, the "bad" kind that forms artery-blocking clots, Ovbiagele said. The benefits of lowering LDL cholesterol levels, in terms of heart disease and stroke, are well known, he said.

"Our study would seem to indicate that triglycerides are more important than LDL cholesterol," he said. "But they haven't been studied in the way of reducing their levels and seeing if that reduces stroke risk. If we reduced triglycerides as aggressively as we reduce LDL cholesterol, we might have equally lower risk, but nobody knows."

The role of LDL cholesterol and other blood fats in stroke has drawn increasing attention from a new breed of specialist, the vascular neurologist, said Dr. Cathy Sila, head of vascular neurology at the Cleveland Clinic.

The study of blood vessels in stroke is much more complex than in heart disease because of the great variety of vessels to be dealt with and the different kinds of stroke that can occur, Sila said.

"Almost all heart attacks are due to atherosclerosis," she said, referring to artery blockage. "Only about half of ischemic strokes are related to atherosclerosis. And we have vessels as big as the carotid artery, which is the size of a pencil; intracranial arteries, the size of linguini; and vessels in the brain as big as the size of a human hair."

The connecting factor in assessing the risk of ischemic stroke in many cases is not just blood levels of fat but the metabolic syndrome, a constellation that includes high blood fat levels, high blood pressure levels and obesity, Sila said.

Success in lowering cholesterol levels with statin drugs has meant "a lack of attention paid to other lipid fractions," she said.

The reported association between triglyceride levels and stroke reinforces the standing recommendations for reducing known risk factors for vascular disease, both Sila and Ovbiagele said.

"We should focus on reducing LDL cholesterol as a primary goal but not ignore triglycerides," Ovbiagele said. "We should also consider a trial to lower triglycerides to see if we can improve on the benefits we get from lowering LDL cholesterol."

More information

There's more on stroke risk factors at the American Heart Association  .

MONDAY, Dec. 10 (HealthDay News) -- About 5 percent of women considered at low risk for heart disease still face potential cardiovascular problems because of calcium buildup in their arteries, a new study suggests.

"Previous studies have demonstrated that calcium is predictive of coronary artery disease in other populations," said study lead author Dr. Susan G. Lakoski, a cardiology fellow at the Wake Forest University School of Medicine. "We traditionally have the question of looking at low-risk people."

The standard method of measuring heart risk is the so-called Framingham risk score, which is based on findings of a decades-long study of residents of a Massachusetts town. The score includes such factors as age, cholesterol levels, diabetes, smoking and obesity, but not calcium.

Lakoski and her colleagues used computerized tomography scans of the chest to measure coronary artery calcium in 3,601 women between 45 and 84 years of age. Ninety percent of the women were considered "low risk," because their Framingham scores indicated they had less than a 10 percent chance of a cardiac event in 10 years. (High risk is a test score of 20 percent or higher.)

Over an average of the next 3.75 years, 24 of the low-risk women had heart events -- such as heart pain or a heart attack -- and 34 of the women had a so-called cardiovascular disease event, including heart events, stroke or death, the study found.

Women with the highest calcium scores were especially at risk, Lakoski said. "They had an 8.6 percent risk of a coronary event," she said.

The findings are published in the Dec. 10/24 issue of Archives of Internal Medicine.

Lakoski said it's probably too early to consider routine testing of coronary artery calcium to gauge heart risk for women. The number of study participants was small, and further research is needed, she said.

Still, Dr. Suzanne Steinbaum, director of Women and Heart Disease at Lenox Hill Hospital in New York City, called the study findings important. "The risk of heart disease in women is often underestimated, because they develop heart disease later than men, often at age 65. By measuring calcium, we can show that they might actually be at higher risk, and that is important because they can benefit from preventive measures."

And heart-risk estimates for women based on traditional risk factors might be misleading because of societal changes, Steinbaum said. "Younger women are developing heart disease earlier than we originally thought," she said. "This is where calcium might be an important modality in classifying risk."

A test for coronary artery calcium is easily done, Steinbaum said, but health insurance companies don't currently pay for it.

While there are no known measures to reduce coronary artery calcium, a woman who knows of its presence can still take preventive measures, Lakoski said. "She needs to offset it with lifestyle measures that affect risk factors that are modifiable, such as cholesterol," she said.

More information

To learn more about coronary heart disease, visit the U.S. National Library of Medicine.