Sarcopenia and its Aftermath
An elderly woman drives to her local store in the early afternoon every Thursday to purchase the week’s groceries. Milk, butter, bread and cheese are her staples. The vegetables vary week to week based on her preference for this dish or that. The fruits that fill her cart never deviate from what can be found in any produce section in any supermarket during any season of the year: bananas, apples, and oranges. On the way to the cashier (she abhors the absence of small talk at the automated scanner), she suddenly remembers that her grandchildren will visit this weekend. She makes a slow pivot for the baking aisle and reaches for the top shelf for a ready-to-bake package of coffee cake. When she reaches overhead, her stance becomes unreliable and she retracts her hand to steady herself. The second time she tries, she gets it, but as she’s pulling the box down, it falls to the ground. She hinges down unaided to retrieve it from the floor. While trying to get upright again, her body fails her. She falls sideways and breaks her hip.
As a nation, we spend two billion dollars a year on medications for osteoporosis. If you factor in the costs of all the fractures that occur nonetheless, the total cost jumps ten-fold. On every evening news program, in countless magazines, pharmaceutical companies advertise the bisphosphonates and hormone therapies that aim to prevent such occurrences. It is the age-related hollowing of dense bone that is the problem. The medications will help re-ossify our weathered skeletons.
But this is an incomplete narrative. We are belatedly learning that another culprit is at play in many of these falls. Sarcopenia is not a term most people are familiar with, but as the great tide of boomers begins to crest into the morbid years of life, it’s a topic that requires greater attention and understanding.
Sarcopenia is the loss of muscle bulk and function that results in a deterioration in activity level. It’s generally due to older age, gender, and low physical activity levels, but a closer look reveals that genetic factors, hormonal changes, mitochondrial dysfunction, inflammation, and nutritional/metabolic alterations all play a role. We’ve focused so myopically on the skeletal system when preventing and treating broken bones that we’ve neglected the large role that muscles pay in such events.
Skeletal muscles are perpetually dancing in an interplay with bones and connective tissue to keep us upright, to safeguard our gait, to aid in breathing, and to ensure that we can perform gravity-related tasks effectively. Much as skin prevents exposure and harm to underlying tissue, muscles to a large extent shield us from injury to bones. As muscles begin to deteriorate, bones become susceptible to blows that might not break them otherwise.
Part of our collective inattention to the degeneration of muscles over time has to do with the paucity of treatments for sarcopenia. You can’t remember being solicited drugs for sarcopenia during commercial breaks for one simple reason. There are none. The standard of care is optimizing nutrition and improving physical activity. But once muscles start to weaken, once activity begins to slow, it’s difficult to reverse the decline. Medicare’s Silver Sneakers program allows seniors free gym membership, but it is only available to a fraction of the elderly. If gym membership was subsidized more broadly or much earlier in life, not only would we be able to prevent sarcopenia, we would tackle a whole host of other diseases tied to inactivity.
But our society’s approach to illness is largely reactive, not proactive, so we’ll likely look to technological solutions to the problem once it sets in. Efforts to stimulate muscles with electrical pulses seem conceptually plausible. Who, after all, wouldn’t want to marry a bodybuilder’s physique with a couch potato’s lifestyle. However, studies show that electrical stimulation only results in modest gains in muscle mass.
Of course, exoskeletons will play a major role in augmenting the movement of sarcopenic people, but the current iterations being utilized in younger patients with spinal cord injuries seem too cumbersome for use in the elderly. I would expect this technology to rapidly advance in the ensuing decades.
Pharmacologic treatments that are being studied aim to steer the body away from the inevitable degeneration of muscles and include hormone therapies, anti-inflammatory medications, and possibly genetic tools like CRISPR that can edit portions of the genome and stanch the march of muscles toward entropy.
The most interesting area involves ex-vivo growth of muscles. In 2015, researchers at Duke created the first lab-grown contracting human muscle. This may be one step toward being able to goad in-vivo muscle to grow itself. Imagine having yearly injections of your own muscle stem cells, optimized in a laboratory for reimplantation into your major muscle groups. The newly implanted cells generate into healthier, younger versions of themselves.
The fitness, wellness, and beauty industries will pounce on such a technology for their own consumers, but that might not necessarily be a bad thing. If we were all modified to be more muscular from a younger age, could sarcopenia become a thing of the past?