Weight loss, a pursuit celebrated for its health benefits, may carry hidden risks, particularly for individuals aged 65 and older. A critical concern that arises is whether popular weight-loss drugs might inadvertently lead to the depletion of vital muscle mass.
When individuals embark on a weight loss journey, whether through medication, strict dietary regimens, or bariatric surgery, it is important to recognize that not all weight shed is exclusively fat. Approximately one-quarter of weight loss often includes the loss of lean mass, comprising muscle and bone, which plays a pivotal role in metabolism and safeguarding against injuries as individuals age.
This phenomenon holds true even for weight loss achieved through the use of GLP-1 medications such as Ozempic and Wegovy. For younger adults, the loss of muscle may not present immediate issues, but for those over 65, preserving muscle mass is crucial for maintaining strength and mobility. Muscle weakness significantly contributes to falls among older adults, a leading cause of injury-related fatalities within this demographic, according to the US Centers for Disease Control and Prevention. Consequently, as Medicare deliberates covering these medications for individuals aged 65 and older, comprehensive studies concerning this population become indispensable.
Dr. John Batsis, an associate professor of medicine in the Division of Geriatric Medicine and Department of Nutrition at the University of North Carolina Chapel Hill, emphasizes, “While there may be many important benefits of weight loss metabolically, we need, particularly in older adults, to think about muscle and how important it is for the older adult population. Losing muscle mass and strength with aging is a natural phenomenon – everyone, though, has a threshold where it causes a problem.”
As of now, there is insufficient data to gauge the extent of this issue among older adults using GLP-1 medications for weight loss, experts caution. Notably, approximately 42% of US adults aged 60 and above grapple with obesity, according to the CDC. In a clinical trial examining semaglutide, the active ingredient in Ozempic and Wegovy, researchers assessed lean muscle mass loss in a subgroup of 140 participants. On average, participants lost about 15 pounds of lean muscle and 23 pounds of fat during the 68-week trial. However, it is worth noting that the mean age of participants in that group was 52.
Dr. Batsis points out that very few GLP-1 studies, in general, have delved into disparities between older and younger adults, including variations in the loss of fat and muscle. Therefore, there is a pressing need for more studies specifically focused on older adults.
Martin Havtorn Petersen, a spokesperson for Novo Nordisk, the manufacturer of Ozempic and Wegovy, asserts that although semaglutide did reduce lean mass, patients concurrently lost more fat, which contributed to an overall improvement in their body composition. Petersen also emphasizes that “there has not been a safety signal identified in relation to the loss of muscle mass.”
In anticipation of potential muscle loss concerns, pharmaceutical companies are already exploring next-generation weight loss drugs. Eli Lilly & Co., for instance, acquired the obesity drug startup Versanis Bio for up to $2 billion in July, further expanding its footprint in the weight loss market. Versanis’ experimental drug, bimagrumab, is designed to assist individuals in shedding weight while preserving their muscle mass.
This innovative drug will be studied in conjunction with Lilly’s drug tirzepatide, expected to receive approval for treating obesity by year’s end. Ruth Gimeno, Lilly’s vice president for diabetes, obesity, and cardiometabolic research, stated, “The combination could be the next major step in innovative treatments for those living with cardiometabolic diseases, like obesity.”
For older adults who may be considering weight loss medications, adopting strategies such as increasing protein intake and engaging in resistance exercises may help mitigate the potential loss of lean muscle, according to Dr. Batsis.