Oxidative damage and platelet activation as new predictors of mobility disability and mortality in elders.

Mobility disability is an early phase of the disablement process in older adults, and represents a major risk factor for physical disability and mortality. Pathophysiological mechanisms responsible for the onset of mobility limitation are still largely unknown. Oxidative damage, responsible for the disruption of the equilibrium of biological systems by damaging major constituent molecules, might play an important role in the pathway leading to major health-related events. It has been suggested the existence of a vicious cycle involving oxidative damage, platelet activation, and inflammation as promoter of pathophysiological changes occurring with aging. This hypothesis is based on the following observations: (a) oxidative damage is associated with diseases and clinical conditions potentially leading to disability and mortality; (b) oxidative damage is associated with platelet activation, and a vicious cycle involving oxidative damage, platelet activation, and inflammation has been demonstrated in several metabolic disorders potentially leading to mobility disability; (c) the age-related physical decline may be associated to the oxidative damage due to the excess of free radicals; (d) antioxidant defense and behavioral factors (e.g., physical activity, dietary restriction, smoking cessation) play an important role in the reduction of oxidative damage levels and are associated with improved physical performance and muscle strength.