Weight loss associated with higher risk for CHF, mortality

Weight gain of more than 5% did not affect CHF risk in patients.

CHICAGO — Weight gain appeared to have a neutral effect on the risk for congestive heart failure, according to researchers from Austria, Germany and the United States.

Numerous epidemiological studies, such as a 2006 study by Adams and colleagues, have shown that increased risk of mortality is associated with an increased body weight during midlife. And although obesity increases the risk for metabolic syndrome, diabetes and the likelihood of mortality in population studies, it is not clear that this holds true in various subgroups with established CVD, according to Carl J. Pepine, MD, chief medical editor of Cardiology Today and eminent scholar, professor and chief, division of CV medicine, University of Florida, Gainesville.

Various reports have suggested that increased BMI in patients with HF or who are undergoing percutaneous coronary intervention or have established CAD may be associated with decreased mortality and morbidity. Pepine said this has been called the “obesity paradox.”

In November, data were presented by researcher Stefan D. Anker, MD, PhD, professor for applied cachexia research, department of cardiology, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, at the American Heart Association Scientific Sessions 2006 that added support to this paradox.

However, “all of these data are observational data and cannot be used to imply cause and effect,” Pepine said. A definitive, prospective study is needed that would randomize patients to a weight loss group or a weight maintenance group for more definitive answers.

Weight loss and CHF

Researchers analyzed weight change and its relationship to CV outcomes in 2,908 participants in the Framingham Heart Offspring Study. All of the patients were older than 30 (mean age 49), and 51% were women. No patients had cancer.

They expected to find that weight loss was associated with increased CHF, according to Anker.

The researchers defined weight change as a percent change in BMI between two exams. The primary outcome was a combination of development of CHF or mortality; the secondary outcome was incident CHF. They adjusted for CHF risk factors, including baseline BMI, alcohol consumption, cholesterol, diabetes, MI and smoking.

The investigators found 261 people who either developed CHF or died, and 80 others with incident CHF during follow-up (mean 14 years). Weight loss of at least 5% was associated with a hazard ratio of 1.59 (95% CI, 1.06-2.39) for CHF or mortality compared with constant weight.

For incident CHF, weight loss was associated with a HR of 2.63 (95% CI, 1.39-4.97). However, weight gain of at least 5% was associated with a HR of 1.06 (95% CI, 0.67-1.68) for CHF or mortality and a HR of 0.89 for incident CHF (95% CI, 0.36-2.19).

For CHF or death among patients who lost weight, the time-varying model was associated with a HR of 1.74 (95% CI, 1.26-2.41) compared with constant weight. The researchers found a HR of 1.17 (95% CI, 0.62-2.18) for incident CHF compared with constant weight.

Among patients who gained at least 5%, the HR was 0.91 (95% CI, 0.64-1.29) for CHF or death compared with constant weight; the HR was 0.59 (95% CI, 0.30-1.15) for incident CHF.

“If you care about survival in general, and not only CV problems, the statement that weight loss is beneficial and weight gain is always bad is not necessarily true,” Anker said. “More studies are needed. Recommending weight loss is rarely good when considering total survival.”

The researchers plan a follow-up study, according to Anker.

Pepine said that it is hard to refute studies on increased body weight, such as Adams et al, but there may be subgroups who do not behave like other patients. Physicians spend a lot of time counseling patients with HF and other vascular disease conditions to lose weight, and it could be a waste of time, he said.

Pepine said that he has not changed anything regarding the way he handles patients and obesity yet, but the matter is getting troublesome. There are about 10 articles about this paradox and “it’s starting to catch my attention. Maybe there is something to this.” – by Lauren Riley

For more information:

• Goehler A, Zietemann V, Siebert U, et al. Association between weight change and incidence of congestive heart failure in the Framingham Heart Offspring Study – death as a competing event. #3172. Presented at: American Heart Association Scientific Sessions 2006; Nov. 12-15, 2006; Chicago.