Walking uphill or down said to aid heart differently
By Stephen Smith, Globe Staff | November 8, 2004
NEW ORLEANS -- It turns out that whether a stroll is taken uphill or down, the cardiovascular system benefits, a finding that researchers predicted yesterday could yield important clues in the nation's increasingly urgent quest to slow twin epidemics of heart disease and obesity.
Scientists from Austria, in a study that a leading US cardiologist deemed unique, reported that while both uphill and downhill jaunts produce a healthier heart, the biochemical consequences are different depending on the direction, a discovery that researchers said demonstrates the exquisite complexity of the coronary network.
The findings could one day lead to better recommendations about which gym exercises most benefit which patients, depending on whether they're diabetic, obese, or suffer from other medical conditions.
The research was presented at the nation's premier gathering of heart specialists, the American Heart Association Scientific Sessions 2004. And while scientists are reporting on high-tech discoveries like a mesh wrap designed to swaddle an ailing heart and restore it to better functioning, their minds are also trained on ways of preventing and slowing heart disease in the first place.
That means examining everything from exercise to the weather.
''It's good to have something to offer people that can help," said Dr. Gerald Fletcher, a cardiologist at the Mayo Clinic's Jacksonville, Fla., facility. ''And it's good to give them things they can enjoy."
One such thing, Dr. Heinz Drexel decided, might be a walk in the Alps. So he enlisted 45 healthy, but not especially active, adults to walk three to five times a week.
During half of the four-month study, they went 600 meters (about 660 yards) up a hill, and for the other half they went down.
After their stroll, a cable car ferried them in the opposite direction.
Drexel and his colleagues at the Vorarlberg Institute for Vascular Investigation and Treatment wanted to know whether the jaunts would have any effect on key measures of cardiovascular health in the walkers.
And they did -- but not necessarily in the same way.
The walkers saw declines in the bad cholesterol known as LDL whether they went uphill (10 percent) or downhill (9 percent). But other effects depended on the direction.
Downhill walking helped to significantly improve the body's ability to process sugar in the blood, while going uphill didn't achieve such an effect.
And when it came to removing potentially dangerous fats called lipids from the blood, walking uphill proved beneficial, while venturing in the opposite direction didn't help much.
''These results are intriguing," said Dr. Peter McCullough, a Michigan cardiologist who studies the effects of exercise on the heart.
The Austrian scientists can't say for sure why the direction a walker goes makes a difference, but they said their findings that going downhill improves the ability to process sugar could prove particularly helpful for some patients.
''This is good, especially for diabetics who can't go upward," Drexel said.
Cardiologists said yesterday that the Austrian findings should be an impetus for exploring with greater precision the benefits derived from gym equipment such as stair climbers and elliptical cross trainers and for developing better advice for patients.
Still, they said, this much becomes clear: To maintain a healthy heart, a mix of exercise is necessary and that, they said, can be achieved without even going to the gym.
''At work," the Mayo Clinic's Fletcher said, ''if you go up and down the stairs, you get credit for that."
While cardiology researchers have known for years that exercise can make the heart stronger, they're increasingly recognizing that the weather, cold weather, in particular, can make the heart more prone to life-threatening complications.
Two separate studies proved that point.
At an Israeli hospital, researchers found that when the temperature dipped into the mid-40s and below, the number of patients turning up with acute heart failure increased by two-thirds, said Dr. Gad Cotter, a Duke University Medical Center scientist involved with the study.
Similarly, an international team of heart specialists, including doctors from Massachusetts, tracked the time of year when nearly 1,000 patients developed sudden rips in their aortas, a potentially lethal condition. They found that whether the patients were in regions with acutely cold winters or even in cities with milder seasonal changes, the result was the same: They were most likely to suffer an aortic tear in the winter.
The scientists are still trying to pinpoint why, but believe a sudden change in weather could precipitate hormonal shifts as well as narrowing of blood vessels. They recommended that when cold weather approaches, both patients and doctors take note.
Stephen Smith can be reached at stsmith~globe.com.
© Copyright 2004 Globe Newspaper Company.
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