Dr. Megan Johnson McCullough — Muscle atrophy is the term for the wasting or thinning of muscle mass. It happens when the balance between protein synthesis and protein degradation alters which leads to a loss of muscle strength and volume. This can happen to a specific limb such as after someone wears a cast or it can happen throughout the entire body.
The causes of muscle atrophy usually fall into two categories: disuse and neurogenic. Disuse atrophy is the most common and happens when muscles aren’t used enough. This is seen in people with sedentary lifestyles or people confined to bed rest. Neurogenic atrophy is more severe and happens when there is an injury or disease. While anyone can experience muscle wasting, it is most common in the elderly. This is due to a condition called sarcopenia in which the person suffers from chronic illnesses like cancer, congestive heart failure, or Type 2 diabetes.
Helping muscle atrophy naturally centers on mechanical stimulus and nutritional support. Resistance training is the gold standard for reversing atrophy, because lifting weights or using resistance bands triggers the body to repair and grow muscle fibers. Diet plays a critical role. Eating enough high-quality protein is essential to provide amino
acids for muscle repair.
When natural interventions aren’t enough, especially in cases of disease-related wasting (cachexia), medications may be necessary. Doctors sometimes prescribe anabolic steroids or selective androgen receptor modulators (SARMs) to help stimulate muscle growth. These come with significant side effects. In cases of neurogenic
atrophy, treatment focuses on the nerve issue, using functional electrical stimulation (FES) to artificially contract the muscles. Researchers are also looking into myostatin inhibitors which can block a protein in the body that naturally limits muscle growth.
As muscle mass decreases, the risk of falling and bone fractures increases. Significant atrophy can lead to metabolic issues, including insulin resistance and a higher risk of developing metabolic syndrome. In cases involving the respiratory muscles, atrophy can even lead to breathing difficulties and decrease in overall life expectancy. The statistics surrounding muscle loss are a wake-up call. After age 30, adults lose between 3% to 5% of their muscle mass per decade. By the time a person reaches 70, the rate of loss can accelerate. Sarcopenia is estimated to affect 10% to 15% of adults over 60, and up to 50% of those over the age of 80. These numbers prove the importance of maintaining an active lifestyle and proper nutrition throughout all stages of life to preserve muscle and independence.
