Sarcopenia is the loss of skeletal muscle mass, strength, and endurance with age.Sarcopenia is different from muscle wasting and cachexia because the muscle loss is slow.  Wasting is the unintentional loss of body mass, lean and fat, which occurs rapidly and usually happens with a terminal illness, such as HIV.  Cachexia is a slower process than wasting and occurs via loss of cellular fluid into the extracellular space, resulting in edema.  This condition often happens in organ failure.  What sets sarcopenia apart is that it does not occur as a result of extreme illness, but is caused to some degree by the passage of time.

Muscle is lost at an average rate of 1-2 percent per year after the age of 50 years. Infiltration of fat in the muscle, along with the loss of muscle itself is the common characteristics of sarcopenia. Muscle circumference or size cannot indicate the presence or absence of sarcopenia.  How one cares for oneself is a large determinant of the severity of sarcopenia one may acquire.  Exercise, especially resistance training, can prevent and even reverse sarcopenia in the older adult because lean body mass is built with training.

Facts:

• Roughly 45% of the U.S. population is sarcopenic

• Healthcare costs in U.S. in 2000 related to sarcopenia= $18.5 billion

• A 10% reduction in the sarcopenic population would save $1.1 billion

• Healthcare expenditures due to sarcopenia cost roughly $900 per person per year

• Lifestyle exercise programs cost about $200 per person per year

• No race or ethnicity is protected from sarcopenia

• Lack of regular physical activity (Hypokinesis)

• Change in protein metabolism

• Endocrine system changes (hormones and factors)

• Loss of neuromuscular function

• Altered gene expression

• Apoptosis (cell death)

• Inadequate nutrition

References for this page (33,44,21,30,49,42)