CIRCADIAN RHYTHMS AND SLEEP IN HUMAN AGING

The frequencies of five common sleep complaints--trouble falling asleep, waking up, awaking too early, needing to nap and not feeling rested--were assessed in over 9,000 participants aged 65 years and older in the National Institute on Aging's multicentered study entitled "Established Populations for Epidemiologic Studies of the Elderly" (EPESE). Less than 20% of the participants in each community rarely or never had any complaints, whereas over half reported at least one of these complaints as occurring most of the time. Between 23% and 34% had symptoms of insomnia, and between 7% and 15% percent rarely or never felt rested after waking up in the morning. In multivariate analyses, sleep complaints were associated with an increasing number of respiratory symptoms, physical disabilities, nonprescription medications, depressive symptoms and poorer self-perceived health. Sleep disturbances, particularly among older persons, oftentimes may be secondary to coexisting diseases. Determining the prevalence of specific sleep disorders, independent of health status, will require the development of more sophisticated and objective measures of sleep disturbances.

The authors determined the prevalence of sleep disorders in a general population through a survey of 1,006 representative households in the Los Angeles metropolitan area. They found an overall prevalence of current or previous sleep disorders in adults of 52.1%. Specifically, they found a 42.5% prevalence of insomnia, 11.2% of nightmares, 7.1% of excessive sleep, 5.3% of sleeptalking, and 2.5% of sleepwalking. These conditions were often chronic and usually started early in life. Insomnia was more frequent in older people, particularly older women, and in people of lower educational socioeconomic status. Insomnia, nightmares, and hypersomnia were correlated with more frequent general physical and mental health problems.