Popular weight loss drugs like Ozempic and Wegovy have shown incredible short-term benefits, from boosting metabolism to pain relief to addiction and cognitive health.
Although these are very promising early signs, it is important to remember that long-term side effects are still becoming apparent.
Recently, some experts have raised concerns A new weight loss drug known as a glucagon-like peptide-1 (GLP-1) receptor agonist may be causing significant loss of skeletal muscle as well as fat loss. But we don’t have enough data to say for sure.
Now, researchers at the University of Alberta in Canada have taken the debate further by bringing up a subset of muscles found only in the heart.
The heart muscle is responsible for our heart pumping blood around the body, but few studies have investigated how these tissues respond to GLP-1 agonists.
Researchers in Alberta administered semaglutide, the active ingredient in Ozempic, to both lean and obese mice without diabetes or heart dysfunction for 21 days.
The obese mice lost about 30 percent of their body weight and 65 percent of their fat mass compared to untreated mice.
In lean mice treated with semaglutide, the researchers noted a loss of about 8 percent in skeletal muscle over three weeks.
Although no changes were observed in cardiac function or heart wall thickness, both groups of mice treated with semaglutide showed a decrease in overall heart mass and individual size of cardiomyocytes.
Authors “Together” conclude“These data show that the reduction in heart size caused by semaglutide occurs independently of weight loss.”
To find out more, a research team led by clinical scientist Matthew Mertens turned to human cells. When human heart muscle cells were treated with semaglutide in the lab, they were found to significantly reduce their size.
Given these results, the authors acknowledge that it is tempting to speculate that semaglutide is responsible for cardiac contraction and atrophy. “But” they Note“No changes observed in recognized markers of atrophy.”
That means we can’t be sure whether semaglutide is causing myocardial atrophy or whether this muscle loss is a bad thing. In some cases, there may be benefits.
Nevertheless, findings in mouse and human cells suggest Semaglutide “may have long-term harm” to the heart muscle.
If the results of this study were extrapolated to living humans, it would mean that people with pre-existing cardiovascular disease or muscle atrophy who are prescribed semaglutide and similar drugs could put their hearts at further risk. means.
It is unclear whether diet or exercise can offset these potential myocardial losses, but this appears to be the case for skeletal muscle loss and should be investigated in future studies.
“We suggest that cardiac structure and function be carefully evaluated in previous and ongoing clinical studies,” said Martens and colleagues at the University of Alberta. conclude.
This call to action is supported by another recent paper published in a journal run by the American Heart Association. claim The effects of GLP-1 agonists on muscle health will be studied in a “more objective and comprehensive” way, especially considering that “a significant number of patients are likely to take these drugs into the future.” should be done.
This research lancet.
