The loss of muscle mass that inevitably accompanies fat loss is a hazard to teens who are prescribed a GLP-1 drug, as we have seen. Not surprisingly, seniors are also at risk.
According to the governmental branch that keeps track of these things, a leading cause of death among that age group is falling, and falling may be caused by what? Exactly — the loss of muscle mass, which holds the bones together and enables them to either move or remain still, as the situation requires.
That is on the physical side, and on the psychological/emotional side, older patients who successfully lost weight might feel they have been given a second chance, a new lease on life. Such a person might be tempted to try a dangerous or downright foolish activity, without the muscular ability to carry it through successfully.
When Madison Muller’s piece was written last year, it included these words about a trial of semaglutide that included 140 participants: “On average, participants lost about 15 pounds of lean muscle and 23 pounds of fat during the 68-week trial.” The mean age of those patients, however, was 52, which is pretty young for this era of ever-aging populations, and so it might reasonably be expected that older patients would not even do that well.
Meanwhile, Eli Lilly is developing the very inelegantly-named bimagrumab, which holds some promise to be a muscle-mass preserver, to be used in combination with the company’s tirzepatide.
Cautious optimism only
When clinical researcher Dr. Donna H. Ryan wrote about next-generation anti-obesity medications, her Introduction implied that in general, the ones in development were not quite meeting expectations:
The goal of medically supervised weight loss has been modest, or at most, moderate, weight loss — principally because that is all that could be regularly achieved.
At the same time, she named two “interesting and unique” examples as “generating much interest.” Specifically, they are the GLP-1 dual agonist tirzepatide (weekly injection) and the “new agent with a unique mechanism of action,” bimagrumab, which not only eliminates fat mass but preserves and promotes the gain of lean mass.
Apparently, although only needed once a month, it must be administered intravenously in the hospital. Still, bimagrumab “gives the first evidence that we might succeed in targeting improved quality of weight loss for our patients.” In the “Conclusions” section of the piece, Dr. Ryan waxes poetic:
Of course, it would be better to live in a world where healthy eating and active living were the default behaviors and where those behaviors were reinforced in a world without undue emotional and financial stress. All of us need to work toward creating that world…
We are, however, not quite there yet. According to one report, although bimagrumab can increase muscle weight in mice and cultured myotubes, it has no demonstrable effect on increasing muscle strength:
On this background, a large controlled study was performed with 251 patients randomized to receiving monthly bimagrumab or placebo for 52 weeks. No change in the study’s primary end-point was noted compared to placebo; all enrolled patients continued to worsen with further deterioration in quantitative muscle strength testing, with more falls, and worsening swallowing.
The Canadian company 35Pharma developed a molecule called HS235 which sounds very promising. Last October, they announced that lab mice who only got tirzepatide “lost 46 percent of their fat mass.” The ones who received a tirzepatide and HS235 combo “lost 64 percent of their fat mass” without, apparently, losing any muscle mass.
Journalist Sumi Sukanya Dutta explained the importance of not losing too much weight, too fast:
Good muscle mass is vital for resting metabolic rate, which, simply put, means the ability of the body to burn calories even while resting… Less muscle is lost with less aggressive weight loss programmes.
Your responses and feedback are welcome!
Source: “Weight-loss drugs pose risks for people over 65, experts say,” BusinessMirror.com, 10/21/23
Source: “Next Generation Antiobesity Medications: Setmelanotide, Semaglutide, Tirzepatide and Bimagrumab: What do They Mean for Clinical Practice?,” NIH.gov, 09/30/21
Source: “Motor System Disorders, Part I: Normal Physiology and Function and Neuromuscular Disorders,” ScienceDirect.com, 2023
Source: “Move over semaglutide, new drug on the horizon promises to melt only fat, not muscle,” ThePrint.in/health, 10/22/23
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