Obesity in Heart Patients Brings Years of Sickness and an Earlier Death
ATLANTA, G.A. -- The more overweight you are, the younger
you will be when heart disease strikes, which will result in
more years of illness and fewer years to live compared to
leaner patients, a large, long-term study has shown.
While the connection between a person's weight and earlier
onset of heart disease has long been made, Duke University
Medical Center researchers have measured the extent of the
relationship by looking at 12 years of detailed data on more
than 9,000 heart patients. The findings were prepared for
presentation at the American Heart Association's
annual scientific sessions.
The researchers uncovered a direct relationship between the
age and the weight of patients when they first came to Duke for
symptoms of heart disease: the median age of normal weight
patients was 64, overweight patients were 61 years old, while
the most obese were 57.
A similar pattern is reflected at the end of life:
normal-weight adults with heart disease had a life expectancy
of 78, compared to 77 for overweight patients and 74 for the
most obese patients.
Moreover, in this study, the heavier the patient, the more
statistically likely that he or she had high blood pressure,
diabetes, high blood levels of cholesterol and a family history
of heart disease. These patients also had heart disease longer
than normal-weight patients, and treating obese patients cost
an additional $10,000 in the 12 years after their initial
cardiac event, compared to normal-weight patients.
"It's a clear message," said Dr. Eric Eisenstein, an
investigator at Duke's Clinical Research Institute. "Patients
who weigh more than is healthy for them are coming into the
hospital earlier because of heart disease, are living with that
disease longer and dying slightly earlier than patients of
"There have been a number of studies that show weight is a
risk factor for developing heart disease, but this study is
different because it looks at how weight affects the long-term
prognosis for patients with known heart disease," Eisenstein
added in an interview. "We found that obesity independently
predicts a reduced life span for these patients after
accounting for other risk factors."
To make these conclusions, the research team looked at the
records and made annual contact with 9,407 patients who had
come to Duke for a diagnostic catheterization between 1986 and
1997. This procedure uses a thin probe to look inside the heart
and is used when symptoms of a heart problem first surface in a
National Institutes of Health guidelines, based on body mass
index (BMI), were used to describe the patients' weight. Within
the group, 31 percent (2,951 patients) were normal weight (BMI
of 18.5 to 25); 42 percent (3,950 patients) were overweight
(BMI of 25 to 30); 18 percent (1,694 patients) were "obese-1"
(BMI of 30 to 35); almost 6 percent (555 patients) were
"obese-2" (BMI of 35 to 40); and almost 3 percent, or 257
patients, were considered "obese-3" (BMI of 40 or greater).
The obese patients tended to be younger and more often were
women or minorities than the overweight or normal weight
patients, Eisenstein said.
Surprisingly, heart disease that was detected in the obese
patients was less severe than that found in normal or
overweight patients, and their 30-day mortality was
comparatively less, the researchers found. "But this all makes
sense, because symptoms of heart disease were occurring earlier
in the obese patients, and it was less advanced at the time of
diagnosis," Eisenstein said. "A similar phenomenon is seen in
people who smoke. Their first cardiac event typically occurs
when they are younger, compared to non-smokers."
That short-term survival advantage disappears as obese
patients live with their heart disease and other disorders,
such as hypertension and diabetes, that arise, he said. For
example, among normal-weight heart disease patients, 50 percent
had hypertension and 18% had diabetes, but almost 65 percent of
obese-1 patients had hypertension and 34 percent had diabetes.
Among obese-3 patients, 72 percent have hypertension and almost
50 percent had diabetes.
Survival is also compromised with increasing weight,
Eisenstein said. The researchers found that heavier patients
had more cardiac "events," such as a heart attack, as well as
an increasing number of treatment procedures like angioplasty
and bypass surgery during the subsequent 12 years of the study.
The time they spent being "sick" with heart disease was more
than 20 percent longer than normal-weight patients, he said.
Finally, using actual data as well as predictive models, the
researchers conclude that obesity at the time heart disease is
initially diagnosed can shorten life expectancy by as much as
four years: normal-weight patients can expect to live to age
78; overweight and obese-1 to age 77, obese-2 to age 76 and the
life expectancy for obese-3 patients is 74.