Sarcopenia is the loss of muscle mass due to the natural aging process.
This decrease in muscle leads to a reduction in a person's strength. As a result, their balance and gait are also affected.
Sarcopenia can have an impact on a person's ability to perform everyday activities, such as climbing stairs, lifting objects, and walking.
According to the International Osteoporosis Foundation (IOF), muscle mass starts to decline around the age of 40. The loss of muscle tissue may progress more rapidly when a person reaches their 60s and 70s.
Although the exact rate of decline varies, a person may lose 3 to 8 percent of muscle mass per decade.
The loss of muscle mass involves both a reduction in the number of muscle fibers and a decrease in their size. The combination of fewer and smaller muscle fibers causes the muscles to atrophy or shrink.
As a person ages, certain changes take place in the body that play a role in the development of sarcopenia.
For example, as a person gets older, their body's ability to produce the proteins that the muscles need to grow decreases. When protein production falls, individual muscle cells get smaller.
Age-related hormonal changes may also lead to a decrease in muscle mass. Typically, levels of testosterone and insulin-like growth factor (IGF-1) affect muscle growth and muscle mass.
The decline in hormone levels may be a contributing factor to the loss of muscle mass.
Although aging is the main cause of sarcopenia, other factors contribute to the loss of muscle mass. They include:
- Living a sedentary lifestyle: Getting little or no physical activity on a regular basis puts people at an increased risk of developing sarcopenia as they age.
- Poor nutrition: Poor dietary habits can also contribute to the development of sarcopenia. Although poor nutrition is possible at any age, it may affect how fast muscle mass declines in older adults.
Older adults tend to eat less, which can lead to malnutrition. According to IOF, up to 41 percent of women and 38 percent of men over the age of 50 eat less protein than the recommended daily allowance.
Eating large amounts of acid producing foods, such as grains and processed foods, and eating too few vegetables and fruits may also negatively affect muscle mass.
Symptoms of sarcopenia may vary depending on how much muscle mass a person has lost. Symptoms include:
- a decrease in muscle size
- loss of endurance
- poor balance
- trouble climbing stairs
A decline in muscle mass may not seem like a big concern for most people. However, muscle loss can be significant enough to cause weakness, increase fall risk, and limit a person's independence.
Sarcopenia may also cause a person to reduce their participation in physical activities. This decrease in activity causes even further muscle loss, which can adversely affect a person's quality of life.
Doctors often diagnose sarcopenia based on the symptoms an individual reports.
In some cases, a doctor may recommend a dual energy X-ray absorptiometry (DXA) and a walking speed test to make a diagnosis.
DXA uses low-energy X-rays to measure skeletal mass. DXA usually measures bone density and tests for osteoporosis. When used in combination with walking speed tests, it may be helpful in diagnosing sarcopenia.
In some instances, doctors may perform additional tests, such as measuring handgrip strength.
Currently, there are no medications approved by the U.S. Food and Drug Administration (FDA) to treat sarcopenia.
Some research is investigating the use of hormone therapy to increase lean muscle mass.
Researchers are studying the use of testosterone and growth hormones to help people maintain muscle mass as they age. But further studies are needed before hormone therapy is recommended to treat sarcopenia.
Although aging is inevitable, developing sarcopenia does not have to be. Fortunately, there are steps people can take that decrease their chances of losing significant muscle mass.
Even if muscle loss has occurred, proper diet and strength training can help people with sarcopenia have a positive outlook and make improvements to the condition.