Sarcopenia, Muscle Weakness in Old Age

As we grow older our muscle strength diminishes and the risk of developing sarcopenia increases. The meaning of the word sarcopenia is an abnormal decline in muscle strength and mass. Another word is muscle atrophy. Between early middle age and older age the mean decrease is 50% of muscle mass. Another way to calculate the loss of muscle mass is that over 50 years of age 1-2% of muscle tissue mass vanishes yearly. Between 50 and 70 years of age almost 15% of muscle strength per 10 years disappears. The resulting disability in older persons with sarcopenia has been calculated to cost approximately 900 dollars per person and year. The yearly total of healthcare expenditures for sarcopenia in the United States is estimated at 18-20 billions (Janssen et al. 2004). 

The concept of sarcopenia is not as well known as osteoporosis, which is the equivalent in bone tissue loss. Even though an older patient has not lost weight, sarcopenia can still be present because of an increased amount of fat tissue. It is important to check the patients for muscle strength as this is a condition which we are able to treat successfully if discovered in time. There are several other reasons for loss of muscle strength in the elderly, such as sickness, inactivity and poor nutrition (Doherty 2003). 

The normal loss of muscle strength in the process of aging is caused by a combination of factors, both genetically and life style components. The life style factors are physical inactivity and low intake of nutritional agents of which protein is the most important. 

The production of both anabolic sex hormones and growth hormone decreases in aging and the result is muscle loss. Also the loss of neural motor cells gives rise to atrophy of the muscles. In the aging process an increased inflammatory activity can be seen and it causes degeneration of muscle tissue through insuline resistance and activation of protein breakdown enzymes. The increased inflammatory activity is due to both normal aging as well as the presence of multiple chronic diseases (Dutta 1997. 

Drugs that increase sedation and give muscle relaxation can have a negative effect on muscle strength and the ability to maintain physical activity, for example, benzodiazepines and other tranquilizers. Corticosteroids have a well known side effect on muscle tissue that leads to muscle atrophy and increases with the dosage. 

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