Researchers examined known risk factors for heart disease, such as body weight and waist circumference, in patients taking part in a clinical trial of semaglutide.
Although the risk of serious cardiovascular disease was lower for those taking the drug, only half of this reduction could be explained by changes in these risk factors.
The findings suggest that semaglutide may also be working to reduce heart disease in some other way, experts say.
Growing popularity
The use of weight loss medications known as GLP-1 receptor agonists, such as semaglutide, have become increasingly popular in recent years.
Previous studies have shown that the drugs, used in the treatment of diabetes, are also effective in lowering cardiovascular disease risk in those who do not have the condition.
A study led by the University of Edinburgh analysed data from more than 17,600 patients taking part in the SELECT trial to understand whether reductions in cardiovascular risk factors could fully account for the drop in heart disease.
Heart health
Half of the study participants were treated with semaglutide and half were given a placebo.
The study examined whether factors like body weight, waist circumference and blood pressure changed over two years. They also examined any changes in blood tests, including cholesterol, and signs of diabetes, inflammation and kidney function.
They compared this information with rates of cardiovascular disease, such as heart attack, stroke or death from cardiovascular disease, in the patients.
Wider benefits
Patients receiving semaglutide lost weight, had reduced waist measurements and improved blood tests.
However, when researchers looked at all these factors separately and together, they could not fully account for the 20 per cent lower rates of heart disease in patients taking the treatment.
Experts say further research is needed to explore how semaglutide could be preventing heart disease, but suggest the drug should be considered as a way of preventing serious cardiovascular disease, over and above its current use as a weight loss treatment.