People with severe obesity who exercise regularly have healthier blood vessels and lower inflammation than those who rely on medication alone, a new study from the University of Copenhagen shows.
More and more people are living with severe obesity, and weight-loss medication is being used widely. But what does that mean for overall health beyond weight loss?
A new study from the University of Copenhagen shows that exercise plays a crucial role in cardiovascular health - even after significant weight loss.
Researchers followed 130 people with severe obesity for one year after they had completed a low-calorie diet and lost an average of 13.7 kg. Participants were then divided into four groups: exercise only, liraglutide only, exercise plus liraglutide, and placebo.
Those who exercised developed healthier blood vessels and lower inflammation. While medication alone helped maintain weight loss, it did not improve vascular health.
"The study shows that while medication supports weight maintenance, it is exercise - with or without medication - that improves vascular health," says Signe Torekov, Professor at the Department of Biomedical Sciences, University of Copenhagen.
Exercise improves vascular health
After one year, researchers measured the thickness of the carotid artery wall - a marker of cardiovascular risk. The thicker the wall, the greater the risk of atherosclerosis, blood clots and stroke.
Participants who exercised saw a 6-7% reduction in artery wall thickness. There was no improvement in the liraglutide-only or placebo groups.
Levels of several inflammatory markers also fell among the physically active participants. Chronic inflammation is a key driver of cardiovascular disease.
Combining exercise with medication led to further weight loss and improved several markers of vascular function.
"Medication can help maintain weight loss, but exercise provides additional health benefits that we do not see with medication alone," says Rasmus Sandsdal, medical doctor and PhD student at the Department of Biomedical Sciences and first author of the study.
Two and a half hours a week made the difference
The effect did not require intense training. Participants in the exercise groups trained on average around two and a half hours a week, mainly spinning and circuit training. Activity was measured objectively using heart-rate monitors.
"What is striking is how little it takes. Replacing just a few hours of screen time each week with physical activity improves cardiovascular health," says Signe Torekov.
To the researchers, the participants were of particular interest because they were obese but still relatively healthy.
"The participants were in their mid-40s and had not yet developed diabetes or heart disease, so it's encouraging that even a modest amount of exercise can improve key risk factors for cardiovascular disease," says Rasmus Sandsdal.
Medication should not stand alone
The study examined liraglutide, an earlier generation of GLP-1 weight-loss medication. The results cannot be directly applied to newer drugs such as semaglutide (e.g. Wegovy), but liraglutide maintained weight loss at a comparable level.
The researchers emphasise that exercise should remain a central part of treatment for severe obesity - especially as more people use weight-loss medication.
"Weight-loss medication is an important tool, but our results indicate that it cannot replace exercise. Physical activity remains essential for protecting the heart and blood vessels," says Signe Torekov.
About the study
- 130 adults with severe obesity participated.
- Participants first completed an eight-week low-calorie diet and lost an average of 13.7 kg (13% of body weight).
- They were then randomly assigned to four groups: exercise only, liraglutide only, exercise plus liraglutide, or placebo.
- The exercise groups on average exercised two and a half hours a week for one year.
- Exercise reduced carotid artery wall thickness and lowered levels of the inflammatory markers IL-6 and IFN-gamma.
- Combining exercise with liraglutide also improved several measures of vascular function.
- The results are published in Nature Metabolism.
