Age impairments in sleep, metabolic and immune functions.

Age-related sleep impairments are chronic and common, occurring even in the absence of diagnosable disorders. Additional loss of sleep occurs with clinical sleep disorders, many of which can be ameliorated. This literature, reviewed below, raises the question of the possible biological consequences of age-related, chronic sleep loss, an area that is poorly understood at present. Some of the more age-relevant theories about sleep loss will be explored in a review of current research on sleep deprivation arising from normal aging, experimental induction and pathology. The biological consequences of sleep deprivation in young adults include metabolic, systemic inflammatory and immune changes that are similar to those of aging and age-related disorders. The possibility that chronic sleep impairment contributes to age changes in metabolism, systemic inflammation and immunocompetence is explored.