NEW YORK (Reuters Health) - Overweight and obese patients with heart failure seem to have a lower risk of dying than their normal-weight counterparts, according to a review of published studies involving more than 28,000 heart failure patients who were followed for an average of nearly three years.
There is evidence, Dr. Antigone Oreopoulos told Reuters Health, that a normal body mass index (BMI) "is likely not the ideal BMI" in people with heart failure, which occurs when the heart loses its ability to pump blood efficiently.
Oreopoulos, from University of Alberta, Edmonton, Canada, and associates reviewed nine studies that examined the impact of BMI on mortality. They pooled the data to estimate the risk of death in patients who are underweight, overweight or obese compared to patients with a normal body weight.
According to the researchers, patients who were overweight or obese were less likely to die during follow up compared to their normal-weight peers. Being overweight or obese "remained protective" against death in a "risk-adjusted" analysis.
Heart failure patients who had a normal weight or who were underweight had the highest death rates. "It remains unknown, however, if higher body fat levels are actually the cause of better outcomes in patients with heart failure," the researchers note in the American Heart Journal.
"We believe there is a need for prospective studies to confirm these findings and elucidate potential mechanisms" for the potentially protective effect of increased body weight on heart failure, Oreopoulos and colleagues conclude.
"Our findings," they point out, "are consistent with evidence in other chronic disease populations," including survivors of heart attack and chronic hemodialysis patients, demonstrating lower death rates with higher BMI levels.
SOURCE: American Heart Journal, July 2008.