Researcher says BMI thin on accuracy in heart-failure patients

“I wanted to contribute to society in hopes that this research might find something,” said Chan.

Chan was one of Antigone Oreopoulos’ study participants in a research project that found body mass index, or BMI, is an inaccurate way to test the body fat status of heart-failure patients. Oreopoulos, from the U of A’s School of Public Health, also found heart-failure patients with more muscle may have a better chance at survival.

Oreopoulos studied 140 patients with heart failure. Study participants underwent a special scan to measure their muscle mass and body fat.

“I wanted to explore something called the ‘obesity paradox,’ whereby once heart failure is established, patients with a higher body-mass index who are considered obese live longer, which is opposite of what occurs in people without the disease,” said Oreopoulos.

Oreopoulos’ research found that having more muscle was associated with better nutritional status and lower severity of heart failure, while higher body fat was associated with increased inflammation and reduced exercise capacity.

“This suggests that in patients with heart failure having more muscle mass and lower fat may be beneficial.”

The study also discovered that testing just the body mass index of heart-failure patients doesn’t accurately measure their body-fat status. Oreopoulos found that 41 per cent of the study participants were inaccurately classified by BMI. Many who had a high body weight but not high body fat were mislabelled as obese and others who did not weigh a lot but had a high amount of body fat were mislabelled as normal.

“I think it’s important to note that we cannot rely on BMI alone as a measure of obesity and risk in patients with heart failure.”

Chan was one of the participants who was inaccurately classified by BMI. Oreopoulos says he was in the highest BMI category at 30.3, which classifies him as obese, but adds this is likely because he has a high amount of muscle mass for his age. This was a surprise to Chan. “I hope the medical community might be more receptive to developing another standard, or supplement with other techniques, in helping their care of heart patients.”

Oreopoulos says this research has direct implications for weight-management guidelines and adds that, to date, there is a shortage of evidence to guide a clinician’s decision about when to recommend weight loss to a patient with heart failure.

While this study provides potential explanations of how muscle and fat could possibly play a role in the survival of heart-failure patients, Oreopoulos says there isn’t enough evidence to make specific recommendations.

“My team and I plan to conduct treatment studies that examine the effects of intentional weight loss on the survival and quality of life in these patients.”

Oreopoulos’ research was published in July in the journal Mayo Clinic Proceedings.

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