Frailty, disability and physical exercise in the aging process and in chronic kidney disease.

Frailty in the elderly is a state of vulnerability to poor resolution of homoeostasis after a stressor event and is a consequence of cumulative decline in many physiological systems during a lifetime. This cumulative decline depletes homoeostatic reserves until minor stressor events trigger disproportionate changes in health status. It is usually associated to adverse health outcomes and to one-year mortality risk. Physical exercise has found to be effective in preventing frailty and disability in this population. Chronic kidney disease (CKD) is also a clinical condition where protein energy-wasting, sarcopenia and dynapenia ,very common symptoms in the frail elderly, may occur. Moreover elderly and CKD patients are both affected by an impaired physical performance that may be reversed by physical exercise with an improvement of the survival rate. These similarities suggest that frailty may be a common pathway of aging and CKD that may induce disability and that can be prevented by a multidimensional approach in which physical exercise plays an important role.