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Long-Term Exercise Prevents Stiffening of the Heart
in Older People
Sept. 14, 2004 - It’s not just aging that causes
stiffening of the heart - it is a sedentary lifestyle, say researchers,
who have also found that long-term exercise can prevent this condition,
which is associated with the onset of heart failure.
Prolonged and sustained endurance training prevents
stiffening of the heart, a condition associated with the onset of heart
failure, according to researchers.
The researchers at UT Southwestern Medical Center
at Dallas report that a sedentary lifestyle, in addition to aging, puts
older people at risk for heart failure, which is the leading cause of
hospitalizations for patients over 65 and a condition that affects eight
out of every 1,000 people older than 70. At the other end, those who do
prolonged and sustained endurance training avoid this heart risk.
“It appears that lifelong exercise training
completely prevented the stiffening of the heart muscle that has been
thought to be an inevitable consequence of aging. We found that it is
aging in addition to being sedentary,” said Dr. Benjamin Levine,
professor of internal medicine and senior author of the study.
“If people can train and sustain it, a huge impact
will be made on one of the biggest scourges of the elderly, which is
heart failure with a normal ejection fraction, also called ‘diastolic
heart failure’. The overall health of the population would radically
improve if a larger number of people would make exercise a part of their
daily life.”
About 40 percent of all hospitalizations for heart
failure in patients 65 and older are due to diastolic heart failure, a
condition in which the heart appears to pump normally. It appears to
occur as a result of stiffening of the heart muscle, causing excess
fluid to accumulate in the lungs, feet, ankles and legs.
The researchers measured the function and
compliance of the left ventricle (the heart’s main pumping chamber) in
the study participants. Twelve healthy but sedentary seniors (all about
70 years old), 12 Masters athletes (average age of 68) and 14 young,
sedentary controls, (average age of 29) were tested. Six of the Masters
athletes, who participate in events from swimming to track, were
nationally ranked competitors and six were regional champions. Sedentary
participants had not engaged in regular endurance exercise throughout
their life.
The researchers tested whether left ventricular
compliance decreased with aging alone, or if physical inactivity
contributed equally to this process.
“We found that the older, sedentary individuals’
hearts were 50 percent stiffer than the Masters athletes, which we
expected,” said Dr. Levine, medical director of the Institute for
Exercise and Environmental Medicine, a collaboration between UT
Southwestern and Presbyterian Hospital of Dallas. “But what we didn’t
expect was that the hearts of these senior athletes were
indistinguishable from those of the healthy younger participants.
“That specific finding led us to conclude that a
sedentary lifestyle is associated with a decline of ventricular
compliance and prolonged, sustained endurance training preserves
ventricular compliance and may reduce the high incidence of heart
failure in the elderly.”
Dr. Levine and his collaborators have already
designed an endurance-training program for several of the elderly,
sedentary study participants, which has already yielded dramatic
results.
“About two-thirds of the sedentary, elderly
participants have trained for a year and there is already improvement in
their cardiac compliance. Their hearts are more muscular and more
flexible,” Dr. Levine said.
A sedentary lifestyle is detrimental to one’s
health, but starting and sticking with an endurance-training program
plays a major role in reversing the damage done to the heart, even if
that program is initiated later in life, he added. Most of the Masters
athletes were not elite athletes when they were younger, Dr. Levine
pointed out. In fact, most of them did not start training until they
were in their 30s.
“It’s not necessarily starting an exercise program
that is important, but sustaining it and making it a part of your daily
life,” Dr. Levine said.
Their findings are to be available online and will
be published in the Sept. 28 print edition of Circulation.
Other researchers who contributed to the study
included Dr. Armin Arbab-Zadeh, a postdoctoral trainee clinician at UT
Southwestern and first author of the study; Dr. Rong Zhang, assistant
professor of internal medicine; Dr. Qi Fu, Dean Palmer, Dr. Pilar
Ochoa-Torres, all from the Institute for Exercise and Environmental
Medicine, along with researchers at the University of Nijmegen in the
Netherlands and the Cleveland Clinic Foundation.
The study was funded by the National Institutes of
Health.
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