Obese heart-failure(HF) patients appear to live longer
than people of normal weight who develop the
disabling condition, a new study suggests.
Researchers tracked nearly 1,500 heart failure
patients, most of whom were overweight or obese
before their diagnosis. They found that 38 percent
of obese and 45 percent of overweight patients died
over 10 years, compared with 51 percent of
normal-weight patients. The difference held even if
they also had other health issues such as diabetes
or high blood pressure. "At this time the reasons
for this beneficial association are not clear," said
lead researcher. It's known that obesity increases
the risk for heart failure, which means the heart
can't pump blood as it should. However, several
investigators have found that in patients with heart
failure, overweight and obesity are associated with
better survival, compared with normal weight. This
is often referred to as the "obesity paradox," she
added. It is possible that obese and overweight
heart failure patients are better able to use
hormones and enzymes to support heart function than
the normal-weight patients, she noted. Thus, obesity
may provide a survival advantage when spontaneous
weight loss occurs as heart failure gets worse, she
said. "However, it is also possible that obese
individuals may show symptoms of heart failure, such
as shortness of breath and swelling, at an earlier
stage of heart failure and be diagnosed earlier,"
she said. This may give rise to the apparent finding
that they live longer, lead researcher said. She
said this is the first study to show that patients
who were obese before developing heart failure
appear to survive longer than normal-weight
patients. Lead researcher added that whether losing
weight could have delayed heart failure isn't known.
Also, "the current study cannot answer whether obese
patients with heart failure could have an
improvement in symptoms and outcomes if they
intentionally lose weight," she said. For the study,
research team collected data on 1,487 people with
heart failure who took part in the Atherosclerosis
Risk in Communities study, an ongoing study
conducted in four U.S. communities. Among these
patients, 35 percent were overweight and 47 percent
were obese about four years before their diagnosis.
Over a decade of follow-up, 43 percent of the
patients died. Survival odds were better for those
who started out overweight or obese, the researchers
found. |