Extra Pounds Protect Against Acute Heart Failure Mortality

January 10, 2007

LOS ANGELES -- For heart failure patients, the "obesity paradox" of better survival rates with increasing heft appears to hold true during acute hospitalization as well, according to a large registry study.

LOS ANGELES, Jan. 10 -- For heart failure patients, the "obesity paradox" of better survival rates with increasing heft appears to hold true during acute hospitalization as well, according to a large registry study.

Every five-unit increase in body mass index (BMI) decreased the likelihood of in-hospital death by 10% (95% confidence interval 0.88 to 0.93, P

In-hospital mortality rates fell in a nearly linear fashion with increasing BMI. The researchers found:

  • 2.2% mortality among patients in the highest BMI quartile between 33.4 and 60.0 kg/m2 (P

Also, the study was limited by absence of data on body fat composition, waist circumference, serum albumin, weight loss before hospitalization, or clinical outcomes after hospital discharge. Body mass index has limitations because it is not a direct measure of body composition and may not accurately reflect the degree of body fat content, especially in patients who have lost muscle mass.

They also pointed out that "there were significant differences in characteristics and treatments by BMI quartile; thus, we cannot exclude residual measured and unmeasured confounding factors other than higher BMI, which may account for the lower in-hospital mortality rates observed in this study."

Dr. Fonarow and colleagues concluded that further research is needed to clarify the mechanisms behind the 'obesity paradox' and to see whether better nutrition may help leaner patients with acute heart failure.

"This study raises the possibility that a therapeutic approach in providing acute nutritional/metabolic support for patients with acute decompensated heart failure has the potential to favorably impact in-hospital mortality," they wrote.