Weight-loss study challenges COPD’s obesity puzzle
Faced with a clinical paradox where obesity seemingly offers a protective effect for Chronic Obstructive Pulmonary Disease (COPD), Hunter researchers have performed a world-first pilot study aimed at achieving weight loss without exacerbating respiratory symptoms.
For a research paper titled “Should we treat obesity in COPD” just published in the international journal Respirology, the project explored whether diet and resistance exercise training can be beneficial to patients.
“We did this study because there’s an increasing proportion of people with COPD who are also obese – in fact it’s now higher than that of the general population. But with this disease, longitudinal data suggests that obese people tend to do better in terms of survival and lung function decline than those of normal weight or under,” lead author Associate Professor Vanessa McDonald said.
“This creates a conundrum for clinicians – we see people who need to lose weight to reduce their risk of other chronic diseases but we don’t know the effect that this has on COPD outcomes. There is no evidence to guide recommendations or clinical guidelines in terms of managing COPD.”
Patients were offered a calorie-controlled diet with meal replacement therapy and nutritional counselling, in addition to a resistance exercise training program delivered by a physiotherapist. Since weight loss in older people is often associated with loss of skeletal muscle, researchers were conscious of the importance of maintaining muscle mass.
The majority of trial participants had moderate to severe disease COPD.
After 12 weeks, they had achieved an average weight loss of 6 per cent and significant fat reduction without compromising muscle composition. Around 70% achieved a clinically significant improvement in their health status.
“What’s really exciting is that it resulted in a major improvement in COPD outcomes, which opposes the obesity paradox, at least for short-term outcomes,” Associate Professor McDonald added.
“People achieved major quality of life improvements. They improved their exercise capacity which is a real predictor of COPD mortality and they became stronger. Our intervention achieved all of this when used in conjunction with standard COPD therapy.”
The pilot study involved 33 people with an average age of 67, of whom 28 completed the trial. The research team from the University of Newcastle and Hunter New England Health now wants to expand the project to a larger sample (110 patients) and over a longer period.
* The research team comprised Vanessa McDonald, Peter Gibson, Hayley Scott, Penelope Baines, Michael Hensley, Jeffrey Pretto and Lisa Wood, researching with HMRI’s VIVA Program. HMRI is a partnership between the University of Newcastle, Hunter New England Health and the community.