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Weight Linked to Late-Life Heart, Diabetes Deaths
By Salynn Boyles
Jan. 10, 2006 -- Adults who are overweight or obese have an increased
risk of dying from heart disease and diabetes later in life, even if
they don't have cardiovascular risk factors such as high blood pressure
or high cholesterol, new research shows.
Obesity is a big risk factor for high blood pressure and high
cholesterol, which, in turn, are big risk factors for heart and
vascular disease.
But the new research, published in the Jan. 11 issue of The Journal of
the American Medical Association, offers some of the strongest evidence
yet that carrying excess weight is an independent risk factor for
hospitalization and death from cardiovascular causes.
"Study after study has shown that overweight and obesity are associated
with higher risks for many health outcomes," researcher Lijing L. Yan,
PhD, MPH, tells WebMD. "What hasn't been clear is whether this risk is
driven by the association with other risk factors."
Study Spanned Decades
Yan and colleagues at Northwestern University in Chicago examined the
relationship between excess weight earlier in life and illness and
death after age 65 by following more than 17,600 people for decades.
The participants were between the ages of 31 and 64 when enrolled in a
Chicago-based heart registry between 1967 and 1973. None had heart
disease or diabetes at enrollment, and the average time of follow-up
was 32 years. Most participants were white.
Cardiovascular risk at enrollment was considered low if the participant met three criteria:
* Did not smoke
* Had normal blood pressure (120/80 or less) and was not taking blood pressure drugs
* Had total cholesterol below 200 mg/dL and was not taking drugs for cholesterol
Weight Matters
People were defined as normal weight, overweight, or obese by their
body mass index (BMI). The BMI is calculated using a person's weight
and height measurements. BMI between 18.5 and 24.9 is considered normal
weight, 25-29.9 overweight, 30 and greater obese.
The researchers found that the risk of dying from heart disease was 43%
higher for study participants who were obese but also met these
qualifications for low cardiovascular risk than for normal-weight,
low-risk participants.
Compared with their normal-weight, low-risk counterparts, the obese
people in the study also had four times the risk of hospitalization for
heart disease and 11 times the risk of dying of diabetes.
Low-risk people who were overweight but not obese had a higher risk of
death and hospitalization from cardiovascular disease and diabetes than
their normal-weight counterparts and a lower risk than people who were
obese.
"Our study is unique in that we had a very long follow up of over 30
years," says Yan, who is a research assistant professor at Northwestern
and an assistant professor at China's Peking University.
"This is only one study, but it adds to the existing picture of the
health consequences of obesity. It is important to try and maintain a
healthy body weight and to work to lose weight or at least not gain
more weight if you already are overweight or obese."
Lose Weight, Get Moving
The American Heart Association has long recognized obesity as a major
risk factor for cardiovascular disease -- one of six modifiable risk
factors along with smoking, high cholesterol, high blood pressure,
physical inactivity, and diabetes.
AHA spokesman and cardiologist Gerald Fletcher, MD, of the Mayo Clinic
in Jacksonville, Fla., tells WebMD that while most people who are obese
also have other cardiovascular risk factors, this isn't always the
case.
He says carrying extra weight puts excess strain on the heart, which
could help explain its role in increasing heart attack and stroke risk
despite other risk factors.
Fletcher says people can lower their cardiovascular risk by losing
weight, not smoking, keeping high blood pressure and cholesterol under
control with medication, and getting active.
That means walking or doing something else to get your heart rate up
from 30 to 60 minutes a day, six to seven days a week, he says. He adds
that only about one in four people in the U.S. get enough
cardiovascular exercise.
"You don't have to do it all at once," he says. "You can spread it
throughout the day, but our data tell us that most people still aren't
doing it. And about 17% of the country is not exercising at all."
SOURCES: Yan, L.L. The Journal of the American Medical Association,
Jan. 11, 2006; vol 295: pp 190-198. Lijing I. Yan, PhD, MPH, researcher
assistant, professor, department of preventive medicine, Feinberg
School of Medicine, Northwestern University, Chicago; assistant
professor, Peking University, Beijing, China. Gerald Fletcher, MD,
cardiologist, Mayo Clinic, Jacksonville, Fla. |
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