Obesity may reduce risk of heart failure death

Obese patients hospitalized with heart failure tend to fare better than their lean counterparts, new research suggests.

The report, which appears in the American Heart Journal, indicates that this "obesity paradox," which was previously described in patients with chronic heart failure, may also apply to patients with rapidly worsening or "decompensated" heart failure.

"This study suggests that overweight and obese patients may have a greater metabolic reserve to call upon during an acute heart failure episode," lead investigator Dr. Gregg Fonarow told Reuters Health, "which may lessen in-hospital (death) risk"

Fonarow of the University of California, Los Angeles and colleagues came to this conclusion after studying data on almost 109,000 heart failure episodes in more than 80,000 patients.

Patients were grouped by body mass index (BMI), a measure of weight relative to height. A normal BMI is between 20 and 25 and subjects in the present study had ones ranging from 16 (very thin) to 60 (very obese).

Those with the highest BMI were younger, were more likely to have diabetes and had higher left ventricular ejection fraction, meaning that the heart was able to pump more blood out with each contraction.

The team found that in-hospital deaths fell as BMI rose, even after accounting for factors including age, gender, blood pressure, and heart rate.

For example, the overall in-hospital death rate was 5 percent in those with the lowest BMI versus 2.2 percent in those with the highest. For every 5 unit increase in BMI, the death risk fell by 10 percent.

The team calls for further study to investigate underlying factors. "These findings," Fonarow noted, "raise the possibility that nutritional/metabolic support may have therapeutic benefit in specific patients hospitalized with heart failure"

SOURCE: American Heart Journal, January 2007.