Study Being fit can lower stroke risk
Fri, 22 Feb 2008 10:02:23 GMTBy STEPHANIE NANO, Associated Press Writer
NEW YORK - Being merely moderately fit — walking briskly half an hour a day — can lower the risk of having a stroke, according to a new study whose findings apply to women as well as men.
Much of the previous research on stroke and fitness has been on men and relied on participants to report their physical activity, said Steven Hooker, who heads the University of South Carolina's Prevention Research Center in Columbia and led the study. About a quarter of those in the new study were women, and everyone had a treadmill test to measure his or her fitness level.
"It seems that benefits we've been observing in men for many years ... are also observed in women," Hooker said.
He said even those who were moderately fit had a lower risk of stroke. Most people can reach that fitness range by walking briskly for 30 minutes a day, five times a week, said Hooker, who presented the findings Thursday at the International Stroke Conference in New Orleans.
Stroke is the nation's third-leading cause of death. It occurs when blood flow to the brain is stopped when a blood vessel is blocked by a clot or bursts. Hooker said physical activity can help prevent blood clots and the buildup of artery-clogging plaque.
For their research, Hooker and his colleagues used data from a study of more than 61,000 adults at the Cooper Aerobics Center in Dallas. After taking a treadmill test, the participants periodically answered health surveys. The latest research divided the group into four levels of fitness and looked at how many of them had strokes, following them an average of 18 years.
Overall, there were 692 strokes in men and 171 in women.
The study found that men in the most fit group had a 40 percent lower risk of stroke than the least fit men. The most fit women had a 43 percent reduction in their risk of stroke compared with women in the least fit group.
For moderate levels of fitness, the risk reduction ranged from 15 to 30 percent for men and 23 to 57 percent in women.
The lower risks held true even when taking into account other risk factors for stroke such as smoking, weight, high blood pressure, diabetes and family history.
Fitness is "a strong predictor of stroke risk all by itself," Hooker said.
The study's participants were mostly white, well-educated and middle-income or higher; other populations should be studied, he said. Fitness tests were only done when people entered the study so the researchers didn't know if their fitness level changed over time.
In its stroke prevention guidelines, the American Stroke Association recommends at least 30 minutes of physical activity of moderate intensity on most days of the week. The new study "is certainly consistent with all of the recommendations that we already have in place," said Dr. Larry Goldstein, a spokesman for the group and director of the Stroke Center at Duke University.
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On the Net:
American Stroke Association: http://www.strokeassociation.org
Naps mammograms may predict stroke risk
Fri, 22 Feb 2008 04:03:43 GMTBy MARILYNN MARCHIONE, AP Medical Writer
NEW ORLEANS - What do mammograms, blood-sugar tests and daytime dozing have in common? All may offer clues that someone is headed for a stroke, new studies suggest. Higher stroke risk was seen in women with artery buildups accidentally revealed by mammograms, in non-diabetics starting to have insulin problems, and in older people who tend to nod off a lot.
People should not panic if they have one of these signs. But if grandma falls asleep in front of the TV all the time, it may be worth checking to see if she has a sleep disorder raising her risk of stroke, doctors say.
Likewise, a test that rules out breast cancer may give a valuable clue to heart disease and stroke risks — if radiologists report the findings to women and their doctors for follow-up.
"You're getting information in two important areas," but people often focus on just the cancer risk, said Dr. Philip Gorelick, neurology chief at the University of Illinois in Chicago. He is chairman of the International Stroke Conference, a medical meeting in New Orleans where the studies were presented Thursday.
Daytime drowsiness may be due to nighttime sleep apnea, a common condition where people briefly stop breathing, causing spikes in blood pressure as they startle awake. Snoring can be a sign, but doesn't always mean trouble — except for others trying to sleep.
"It's not healthy because you're not staying in your normal sleep pattern. You're waking up many times in the night and in the daytime are tired," Gorelick explained.
Columbia University researchers led by Bernadette Boden-Albala found that a simple scoring system to evaluate daytime dozing strongly predicted stroke risk. They asked 2,100 people, average age 73, how often they nodded off during specific situations during the day — watching TV, reading, sitting and talking to someone, sitting in traffic, or sitting quietly after lunch.
In the next two years, 40 had strokes and 127 had other blood vessel-related problems such as heart attacks or blood clots in the lungs.
The odds of having a stroke were nearly five times greater among heavy dozers, and nearly three times greater among occasional dozers, compared with people who rarely nodded off. The chances of other vessel-related problems were higher, too.
Unintentional dozing is different from purposely taking a nap, although "we need to look at that" to see if regular siestas also are a sign of poor nighttime sleep, Boden-Albala said.
Frequent dozers should talk with their doctors about being evaluated for a sleep disorder. Possible solutions include a device that helps maintain continuous air pressure, losing weight if they are overweight, and even surgery if the airway is obstructed.
The mammography study was led by medical student Amy Loden and Dr. Paul Dale of the University of Missouri Medical School in Columbia, Mo. They studied calcium deposits in the walls of arteries that supply the breasts, which are different from the calcifications in breast tissue that can signal the presence of a tumor.
"Every time I see one I think, 'That woman has a breast full of calcifications. I wonder if her heart looks the same,'" said Dale, a cancer surgeon.
He previously published studies tying these artery deposits to a higher risk of heart disease. In the new study, he and fellow researchers found these deposits in 11 percent of roughly 800 women having routine mammograms at their hospital.
Next, they looked at the mammograms of 204 stroke patients and found the deposits in 56 percent of them — five times more often. Greater stroke risk was seen in women of all ages with the deposits, but especially among those in their forties and fifties.
"We're not saying just because you have these you're going to have a stroke — it's just identifying women at risk," Dale said.
He is starting a new study to see whether calcium deposits can be used to predict who will suffer strokes later, and thinks radiologists should report deposits to doctors so follow-up tests can be considered for stroke and heart disease.
Radiologists usually do not report artery deposits, which are more common as women age, said Dr. Carol H. Lee, an American College of Radiology spokeswoman from Memorial Sloan-Kettering Cancer Center in New York.
"I don't know that many radiologists emphasize it, especially in older people," she said.
"It may be a simple marker" for the risk of a lot of things, said Dr. Ralph Sacco, neurology chief at the University of Miami Miller School of Medicine.
The third study looked at clues of stroke risk from a different test — HOMA, a ratio of blood-sugar and insulin levels measured after fasting. High scores signal insulin resistance, a condition where the body is not able to effectively use that hormone to turn food into energy, raising the risk of diabetes.
Dr. Tatjana Rundek at the University of Miami led a study of 1,735 non-diabetic people, average age 68, participating in a long-running study of stroke risk in New York, funded by the federal government.
One-fourth had high HOMA scores, and in the next seven years, they had twice the risk of stroke compared to those with low scores.
The test isn't routinely done, but blood-sugar levels are frequently tested and may give a warning of more than diabetes risk, doctors said.
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On the Net:
Stroke conference: http://www.strokeassociation.org
Treatment limits bleeding stroke damage
Fri, 22 Feb 2008 22:08:34 GMTBy MARILYNN MARCHIONE, AP Medical Writer
NEW ORLEANS - Aggressively lowering blood pressure in the early hours of a bleeding stroke can limit its severity, a preliminary study found, giving hope of a major advance for treating this often-fatal problem.
These strokes happen when a vessel in the head bursts or leaks, flooding brain tissue with blood and damaging areas that control walking, talking and other functions. More than 100,000 occur each year in the United States — a million worldwide — and half prove fatal.
"It is a major public health problem," said Dr. Philip Gorelick, neurology chief at the University of Illinois in Chicago and chairman of the International Stroke Conference, where the new study was reported on Friday.
Doctors know that high blood pressure raises the risk of these strokes, but it isn't known if it's safe to rapidly lower it right after one occurs.
The study tested this in 404 stroke patients in Asia and Australia. Half were given usual care — intravenous drugs to lower systolic blood pressure to 180; the rest had their blood pressure lowered to 140. Normal is 120.
Additional bleeding was about one-third less in the more aggressively treated patients, and the treatment proved safe with no major side effects, said Dr. Craig Anderson of the University of Sydney in Australia, who led the research.
The finding needs to be confirmed in a larger study, but emergency doctors "will probably grab on it," said Dr. Larry Goldstein, director of Duke University Medical Center's stroke center.
The Australian government's health agency paid for the study and will fund one with 2,500 patients starting later this year.
Also at the conference, doctors got mixed news from tests of two treatments for the more common type of stroke — caused by a clot in a blood vessel supplying the brain.
One of the biggest challenges is finding something to help the vast majority of patients who seek help beyond the three-hour window when the clot-busting drug TPA is known to be effective.
Some late-arrivers still have areas of brain tissue that are threatened but might be saved. Researchers in Australia, Belgium, New Zealand and Scotland used imaging tests to identify 101 such patients and gave roughly half of them TPA about five hours after symptoms started.
The main goal — reducing the area of the brain left damaged — was not met. But there were signs that the treatment helped restore the air and blood supply, which should translate to better outcomes for patients when tested in a larger study, research leaders said.
"The trends are going in the right direction; they just haven't proved it," Goldstein said.
A larger study testing TPA beyond three hours is to report results later this year.
TPA is marketed in North America by Genentech as Activase, and by Boehringer Ingelheim in other countries as Actilyse.
A different treatment for people too late for TPA — a mini-vacuum device to suck out clots — opened blood vessels in 82 percent of the 125 patients given the treatment, other doctors reported.
However, 11 percent developed major bleeding in the brain, and another 17 percent had lesser bleeding. In two cases, doctors punctured the blood vessel while trying to suction out the clot. In a third case, another brain bleed developed in a different area.
With TPA, about 6 percent of patients develop bleeding in the brain, and half of those patients die, Gorelick said.
About one-third of patients in the study died — an acceptable result considering how serious these strokes are, he said. Only 42 percent of those whose vessels were reopened had substantial improvement a month later — "and that's the issue," rather than how often the clot can be pulled out, he said.
The device, made by California-based Penumbra Inc., was approved in December by the federal Food and Drug Administration, which requires less proof of effectiveness for devices than for novel drugs, Gorelick and Goldstein said.
The study had no comparison group and was sponsored by the company, they noted. The doctor who presented results — neurosurgeon Cameron McDougall of Barrow Neurological Institute in Phoenix — said he had no control over its design.
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On the Net:
Stroke conference: http://www.strokeassociation.org
