Muscle growth begins when a baby is born and continues until about the age of 30. During this time, muscles become stronger and larger. Once a person reaches their thirties, the loss of muscle function and mass begins. The reason is sarcopenia due to age. If a person remains physically inactive, roughly three to five percent of their muscle will be lost every 10 years once the age of 30 is reached. Some muscle loss will still occur even if the individual remains active.
There is currently no single test to diagnose sarcopenia based on a specific loss of muscle. Regardless of the amount of muscle lost, both mobility and strength will decrease. Sarcopenia generally occurs quicker at about the age of 75. The process can also accelerate by age 65 or not until the person reaches 80. This is one of the factors considered in older adults when the likelihood of falling and frailty are considered.
Causes of Sarcopenia
There is no specific decline rate for sarcopenia. Some people lose three percent of their muscle every decade while others lose as much as eight percent. When muscle is lost, muscle fibers are decreased in size and the number is reduced. When smaller and fewer muscle fibers are combined, the result is atrophy or shrinkage of muscles. As the aging process continues, changes in the body take place and are believed to be a part of developing sarcopenia.
The aging process generally causes sarcopenia because proteins are no longer produced by the body. Muscles require these proteins for growth. When protein production is not working properly, individual muscle cells start to become smaller. Hormonal changes triggered by age can also cause sarcopenia. Declining hormone levels are also believed to contribute to losing muscle.
Signs and Symptoms of Sarcopenia
Symptoms of sarcopenia often interfere with physical activities and can include decreased stamina and weakness. Muscle shrinks further with decreased physical activity. The majority of people with this condition are inactive but it can occur in those physically active. Researchers believe other factors contribute to sarcopenia including:
- Decreased concentrations of specific hormones including IGF-1
- Loss of muscle due to a deficit in daily protein and calorie consumption.
- Nerve cells sending signals originating with the brain and traveling to the muscles to begin movement are reduced.
- Protein is no longer turned into energy at the same rate.
The additional symptoms of this condition vary according to the amount of muscle lost and can include:
- Poor balance
- Muscle weakness
- Walking at a slower speed
- Decreased muscle size
- Difficulty with regular daily activities
- Difficulty climbing stairs
- Decreased endurance
- Muscle wasting
Although many people do not believe the loss of muscle is significant, it can result in limitations on the individual's independence. Many people decrease physical activities leading to additional muscle loss negatively impacting their quality of life.
At this time, the FDA has not approved any medications for the treatment of sarcopenia. Research is being conducted to determine if lean muscle can be increased with hormone therapy. The use of hormones is being studied to determine if it is beneficial for muscle maintenance as people age. Additional research is required before hormone therapy can be officially recommended for the treatment of sarcopenia. Currently, managing sarcopenia is based on preventing muscle loss with lifestyle changes.
Treatment of sarcopenia requires good nutrition and the condition can often be delayed or prevented. Normal levels of muscle can sometimes be built and sustained by consuming healthy proteins including quinoa, lentils, nuts and fish. Eating sufficient protein is essential to help prevent sarcopenia. Consuming specific dietary supplements can help improve or prevent sarcopenia.
Exercise is essential to work muscles and help maintain strength and muscle. Muscles will shrink if they are not used. Muscle tone, strength and size can be improved with either resistance or strength training. Proper training also strengthens tendons, ligaments and bones and is recommended for overall health. Resistance is important for strength training because it can trigger muscle contractions to increase both strength and muscle size.