Research by Dr. Jason Dyck reveals a weight-loss drug can also shrink heart muscle in mice and human cells

By Michael Brown, Folio

Trendy weight-loss drugs making headlines for shrinking waistlines may also be shrinking the human heart and other muscles, according to a new University of Alberta study whose authors say should serve as a “cautionary tale” about possible long-term health effects of these drugs.

“If people have been prescribed these drugs, then the benefits should likely far exceed the risks,” says Jason Dyck, lead author on the study, pediatrics professor in the Faculty of Medicine & Dentistry and a member of the Women and Children’s Health Research Institute.

“However, the growing number of people who may be taking these drugs who do not meet the eligibility criteria and who are not at risk have a different risk-reward calculation that they should be made aware of.”

Dyck and his team set out to study why a reported side-effect of the leading weight-loss drug Ozempic is the loss of skeletal muscle.

Ozempic, known medically as semaglutide, was originally designed to help adult patients with type 2 diabetes control their blood sugar. However, this drug — and a host of others in this class of medication — are also being touted for their effectiveness as an anti-obesity medication.

Using mice for the study, the researchers found that heart muscle also decreased in both obese and lean mice. The systemic effect observed in mice was then confirmed in cultured human heart cells.

Dyck, who is the Canada Research Chair in Molecular Medicine and heads up the Cardiovascular Research Centre, says his team did not observe any detrimental functional effects in hearts of mice with smaller hearts and thus would not expect any overt health effects in humans. But he adds that there may be more impact over the long term, or some forms of cardiac stress may have a detrimental effect that wasn’t observed at rest.