Muscle atrophy or “muscle wastage” is a medical problem where a person loses muscle tissue. This makes the person's muscles weaker. With muscle atrophy, muscles can waste away completely, or only partly.
Many older people have muscular atrophy. Muscle atrophy can also happen to people with certain diseases or medical conditions, like cancer, AIDS, congestive heart failure, Chronic obstructive pulmonary disease, and renal failure (where the kidneys do not work correctly). Muscles can atrophy (or get smaller and weaker) when those muscles are not used as much as usual - for example, when a person has to wear a cast for a broken arm or leg, or when a person must be on bed rest for a long time during a long illness. Muscle atrophy can also be caused by Dejerine Sottas syndrome, cachexia, burns, liver failure, and starvation.
Muscular atrophy can cause serious problems in a person's life. As the person loses muscle strength, he will lose the ability to do more and more things. When he tries to do things, he will be more likely to have accidents. Muscular atrophy also increases the risks of falling among people with certain medical conditions, such as IBM (inclusion body myositis).
No one knows exactly what causes muscular atrophy. It may be due to the gradual failure in the "satellite cells" which help to regenerate skeletal muscle fibres, and a decrease in sensitivity to or the availability of secreted growth factors which are necessary to maintain muscle mass and satellite cell survival.
In muscle atrophy, the normal balance between protein synthesis and protein degradation changes. There is a down-regulation of protein synthesis pathways, and an activation of protein breakdown pathways. In the ATP-dependent ubiquitin/proteasome pathway, particular proteins are targeted for destruction by the ligation of at least four copies of a small peptide called ubiquitin onto a substrate protein. The substrate is later targeted for destruction by the proteasome.
Muscle atrophy can be treated
Symptoms
If everyday movements, such as walking, climbing stairs, cycling or simple household chores are more difficult than usual, this may be due to a lack of or failure to exercise beforehand. The risk of falling or making incorrect movements during such simple movements, in addition to sustaining injuries, increases the longer the period of inactivity. Older people are a particularly vulnerable social group.
Inactivity (e.g. due to chronic (joint, back)painor therapeutic immobility, e.g. due to aplaster cast);
Disturbance of muscle metabolism;
Neuromuscular diseases: Failure of thosenervesthat respond to muscles; these diseases are often genetic (muscular dystrophies);
Autoimmune diseases- polymyositis, dermatomyositis, inclusion body myositis, interstitial myositis.
Other wasting diseases such asHIV/Aidsandcancer(cachexia)
Adverse drug reactions (e.g. Levofloxacin)
Due to the reduced strength of the muscles (muscle hypotonia), pain can occur even at low levels of exertion.
Questions and Answers
Q: What is muscle atrophy?
A: Muscle atrophy, also known as "muscle wastage", is a medical problem where a person loses muscle tissue, making the muscles weaker.
Q: Who can be affected by muscular atrophy?
A: Many older people and those with certain diseases or medical conditions such as cancer, AIDS, congestive heart failure, Chronic obstructive pulmonary disease and renal failure are at risk of developing muscular atrophy. It can also occur when someone has to wear a cast for a broken arm or leg or must be on bed rest for an extended period due to illness. Other causes include Dejerine Sottas syndrome, cachexia, burns, liver failure and starvation.
Q: What are the effects of muscular atrophy?
A: As the person loses muscle strength they will lose the ability to do more and more things. They may also be more likely to have accidents when trying to do things and it increases their risk of falling if they have certain medical conditions such as IBM (inclusion body myositis).
Q: What is thought to cause muscular atrophy?
A: The exact cause of muscular atrophy is unknown but it may be due to gradual failure in the "satellite cells" which help regenerate skeletal muscle fibres and decreased sensitivity or availability of secreted growth factors necessary for maintaining muscle mass and satellite cell survival. In addition there is a down-regulation of protein synthesis pathways and an activation of protein breakdown pathways in ATP-dependent ubiquitin/proteasome pathway which targets particular proteins for destruction by ligation onto substrate proteins that are later targeted for destruction by proteasomes.
Q: Is there any treatment available for muscular atrophy?
A: Yes, there are treatments available for treating muscular atrophy depending on its severity including physical therapy exercises that focus on strengthening weakened muscles; electrical stimulation; medications such as corticosteroids; nutritional supplements; stem cell transplants; gene therapy; surgery; lifestyle changes like eating healthy foods high in protein; avoiding smoking and drinking alcohol etc.
