Overweight People With Heart Failure Have a Lower Death Rate

Curtis JP, Selter JG, Wang Y, et al.: The obesity paradox: Body mass index and outcomes in patients with heart failure. Arch Intern Med 165:55-61, 2005.

What is the problem and what is known about it so far?

For most people, being obese or overweight gives them a greater risk of illness, disability, and death. But in past studies of patients with diseases such as heart failure, overweight and obese people had a lower risk of death. Despite this, many doctors still tell their patients with heart disease and heart failure to lose weight.

Who did the researchers study?

The researchers studied people with stable heart failure (a type of heart disease) who previously joined in a large drug study. A total of 7,767 people were studied. They were grouped according to their body mass index (BMI, a measure of weight in relation to height), BMI under 18.5 was underweight, BMI from 18.5 to 24.9 was healthy weight, BMI of 25.0 to 29.9 was overweight, and BMI of 30 or more was obese.

How was the study done?

Researchers studied death rates of these heart-failure patients for more than 3 years. They compared death rates among the four BMI groups. They also looked at how often people were admitted to the hospital -- for heart failure or any other cause.

What did the researchers find?

Overweight and obese people with heart failure had a lower risk of dying than healthy-weight and underweight people. Underweight people were at the highest risk for death.

What were the limitations of the study?

The study looked at BMI when patients signed up for the study. There was no information on their weight loss or weight gain. There could be other reasons for what the researchers found, such as heart failure being found earlier in overweight and obese patients. Also, the researchers weren’t sure how many patients were eating poorly. And the study was done before doctors started giving patients beta-blockers (a certain type of medicine) for heart failure.

What are the implications of the study?

Before telling people with heart failure to gain or lose weight, doctors need more information on what makes patients with lower BMI have a higher risk of death.