Sarcopenia and aging.

Sarcopenia refers to the gradual decline in muscle mass and quality noted with advancing age. There is growing evidence linking sarcopenia to functional disability, falls, decreased bone density, glucose intolerance, and decreased heat and cold tolerance in older adults. Factors implicated in the etiology of sarcopenia include decreased physical activity, malnutrition, increased cytokine activity, oxidative stress, and abnormalities in growth hormone and sex steroid axes. At present, progressive resistance training is the best intervention shown to slow down or reverse this condition. Preliminary studies show that the utilization of several trophic factors, notably testosterone and DHEA, may have a salutary effect on muscle mass and/or strength in older adults. More research is needed, however, before drawing definite conclusion as to the clinical utility of these substances in the management of sarcopenia.