Midlife Obesity Affects Health Later On
Weight Linked to Late-Life Heart, Diabetes Deaths
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 Dec. 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
- Did not smoke
- Had normal blood pressure (120/80 or less) and was not taking blood
- Had total cholesterol below 200 mg/dL and was not taking drugs for
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."