Sleep disorders in older people

Abstract

Sleep is an essential physiological process, occurring in all higher animals and even those as simple as the roundworm. Whilst some animals have adapted their sleep to specific circumstances e.g. the dolphin sleeping with each side of its brain alternately, no animal has evolved to survive completely without sleep. Animals completely deprived of sleep eventually die as a consequence, usually from immunological collapse and sepsis. Adult humans require between 7.0 and 8.4 hours sleep daily and inadequate sleep is associated with increased mortality, morbidity, reduced quality of life and, in the older people, an increased rate of institutionalization. Even when corrected for comorbidities, men sleeping less than 6 hours a night have a mortality significantly greater that of their peers [1]. Although the population group with the highest prevalence of sleep disorders is those over 65 years there is relatively little published specifically concerning sleep in elderly people. Sleep disorders can be markers for other systemic diseases, yet a recent study found that a routine sleep history is taken in less than 10% of medical cases [2].