Anti-obesity jabs could reduce the risk of heart attacks, strokes or heart failure in obese people regardless of the amount of weight they lose while on the drug, according to a study.
This suggests the treatment could have effects beyond reducing unhealthy body fat, researchers said.
A team led by Professor John Deanfield, of University College London (UCL), used data from the Select trial, which was conducted by semaglutide manufacturer Novo Nordisk.
The five-year study explored if the drug – sold under the brand names Wegovy, Ozempic and Rybelsus – could reduce the risk of heart attacks or stroke in obese people without diabetes.
It comprised 17,604 adults over the age of 45 from 41 countries.
Prof Deanfield’s analysis of Select examined the amount of time before patients suffered major cardiovascular events – such as heart attack or stroke – or whether they developed heart failure.
After 20 weeks of being on semaglutide, 62% of patients had lost more than 5% of their bodyweight compared with 10% in the placebo group.
However, the risk reduction of heart attacks, stroke or heart failure was similar in patients who lost more than 5% of their bodyweight and in those who lost less than 5%, or gained weight.
Prof Deanfield said the findings “have important clinical implications”.
“Around half of the patients that I see in my cardiovascular practice have levels of weight equivalent to those in the Select trial and are likely to derive benefit from taking semaglutide on top of their usual level of guideline-directed care,” he added.
“Our findings show that the magnitude of this treatment effect with semaglutide is independent of the amount of weight lost, suggesting that the drug has other actions which lower cardiovascular risk beyond reducing unhealthy body fat.
“These alternative mechanisms may include positive impacts on blood sugar, blood pressure or inflammation, as well as direct effects on the heart muscle and blood vessels, or a combination of one or more of these.”
In August, researchers working on the Select trial found semaglutide reduced the risk of a heart attack or stroke in obese people with cardiovascular disease by a fifth.
A 2.4mg once-weekly dose of Wegovy, alongside standard care for the prevention of heart attacks or stroke, lowered the risk by 20% compared with those given a placebo.
Prof Deanfield’s study is one of two pieces of research based on the Select trial that are being presented at the European Congress on Obesity (ECO) in Venice.
The second, led by Professor Donna Ryan, of Pennington Biomedical Research Centre in New Orleans, looked at the long-term effect of semaglutide on weight.
She said weight loss using semaglutide “can be sustained for up to four years” in adults who are overweight or obese, without diabetes.
Patients on semaglutide lost an average 10.2% of their body weight and 7.7cm from their waistline compared with 1.5% and 1.3cm respectively in the group given a placebo.
After two years, some 52% of people treated with semaglutide had moved down to a lower BMI category compared with 16% in the placebo group.
Prof Ryan added: “This degree of weight loss in such a large and diverse population suggests that it may be possible to impact the public health burden of multiple obesity-related illnesses.
“While our trial focused on cardiovascular events, many other chronic diseases including several types of cancer, osteoarthritis, and anxiety and depression would benefit from effective weight management.”
Prof Ryan’s findings have also been published in Nature Medicine.
