As Ozempic use rises, a new study in mice suggests the drug may affect muscle strength despite minimal changes in muscle mass. This discovery underlines the need for human clinical trials to fully understand the implications.
With the increasing popularity of Ozempic for diabetes management and weight loss, researchers are turning their attention to its potential side effects, particularly concerning muscle mass and strength. New research from the University of Utah Health has uncovered surprising results from a new study on mice, revealing that Ozempic may reduce muscle strength even if muscle size remains largely unchanged.
The study, published in the journal Cell Metabolism, raises important questions about the broader implications of Ozempic use and emphasizes the urgent need for clinical research in humans.
“If we want to really help the individuals who may be losing muscle mass, then we need to know that they’re actually losing muscle mass,” senior author Katsu Funai, an associate professor of nutrition and integrative physiology in the University of Utah College of Health, said in a news release. “We have data in mice that suggest that things are not as straightforward as they might seem.”
Weight Loss and Lean Mass
The researchers observed that Ozempic-induced weight loss resulted in a 10% reduction in lean mass, most of which came not from skeletal muscles but from other tissues like the liver, which decreased by nearly half.
This suggests that organ size reductions are part of healthy weight loss, a point emphasized by co-first author Ran Hee Choi, a research instructor in nutrition and integrative physiology at University of Utah Health.
“It’s unlikely that the observed lean mass loss represents a serious adverse effect,” added co-first author Takuya Karasawa, a postdoctoral researcher in the University of Utah Molecular Medicine Program.
Size vs. Strength
While skeletal muscle shrinkage was minimal, averaging around 6%, the real concern arose when the researchers tested the muscles’ force-generation capacity.
They found that muscle strength decreased in some instances despite minimal size reduction. This aspect of Ozempic’s impact is particularly worrying for older adults, who face a higher risk of muscle loss and decreased mobility with age.
“The loss of physical function is a strong predictor of not just quality of life but longevity,” Funai added.
Call for Clinical Trials
The study underscores the importance of translating these findings from mice to humans, as the weight gain and loss mechanisms differ significantly between species.
“There remains a significant need for validation in humans, especially concerning muscle strength,” added Karasawa.
Future clinical trials of Ozempic and other weight-loss medications should not only measure lean mass loss but also changes in physical function, Funai emphasized.
“There are many additional weight loss drugs that are in clinical trials and coming out in the next three to five years,” he added. “But with all those clinical trials, if they’re interested in measuring lean mass loss, they need to consider physical function.”
Despite the intriguing results, Funai advises caution, noting the preclinical nature of the study.
“Our findings are really interesting, but this is a preclinical model,” he added. “We need these data in people.”
Source: University of Utah Health