A study into the effects of Ozempic on muscle mass in mice has highlighted the need for more robust clinical trials of the use this and other weight-loss drugs in humans, reports SciTechDaily
As diabetes-turned weight-loss drug Ozempic (semaglutide) enjoys a rapid rise in popularity, concerns have been raised about the treatment causing a loss of lean mass, potentially compromising physical function and quality of life.
A STEP-1 trial of the drug found that of the weight lost, around 45 percent was loss of lean mass, a figure that exceeds the 25 percent considered standard for weight loss. Researchers from the University of Utah conducted a mouse study to dig into how much of that loss is from skeletal muscle mass, how much is a return to baseline, and how much overall strength is lost.
Clarifying these questions, they note, is crucial for gaining a deeper understanding of the long-term health effects of semaglutide-induced weight loss on humans.
[See more: What is ecnoglutide, the new Chinese weight-loss drug outperforming Ozempic in clinical trials?]
They found that while muscle mass decreased less than expected in mice, some muscles still became weaker. Mice in the study experienced a roughly 10-percent drop in lean mass, most of which came from organs shrinking.
While that may sound scary, “loss of mass in metabolically active organs, such as the liver, is expected as part of healthy weight loss,” Ran Hee Choi, PhD, research instructor in nutrition and integrative physiology at University of Utah Health and co-first author on the study, told SciTechDaily.
Weight gain and loss affect the size of organs in both mice and humans, without affecting their function and one researcher noted that it’s unlikely the change observed in the study represented a serious adverse effect.
Some skeletal muscles did shrink, around 6 percent on average, but the researchers note that this could be a return to normal. People’s skeletal muscle often grows as they gain weight, helping to support the added mass, and shrinks as weight is lost without harming regular functioning.
However, researchers found that the mice lost strength in some muscles as they lost weight, even when the muscles stayed roughly the same. If their findings hold true for humans, taking Ozempic could pose a risk to people over 60, who are already at higher risk for muscle loss and reduced mobility. Research on humans is needed to validate these results, they emphasise, stressing that clinical trials for all current and future weight-loss drugs should check for changes in muscle strength.
