Interfacing sleep and aging

Abstract

- Daniel Francois Esprit AuberSleep disruption is one of the most chal-lenging problems occurring with advanc-ing age and additionally represents the most frequently expressed health com-plaint among the elderly (Monjan, 2007). Despite the ubiquity of the problem in modern times, disturbed sleep may not have always been a significant health prob-lem, and it is possible that prehistoric man suffered neither the frequency nor intensity of sleep disruption that is so commonly reported today. Evidence suggests that man’s lifetime was much shorter during the Paleolithic, Mesolithic, and early Neolithic periods, averaging only about 30–40 years (Thorpy, 2001). It would thus appear that in addition to the benefit of an extended lifespan, which in large measure has been provided by medicine and technology, one of the health costs of living in mod-ern times is the gradual reduction in sleep quality which man experiences as he ages. The field of sleep medicine has developed considerably over the last 50 years, with dramatic improvements being seen in the diagnosis, treatment, and management of sleep disorders (Shah et al., 2006). Sleep is very often considered to be a barometer of health and as we age, the parallel increases in chronic diseases (medical and psychi-atric comorbidities) various stressors, and increased consumption of medications, tend to take a toll on the quality of sleep we experience. Thus as we age we begin to experience a tradeoff between the benefits having a longer life, while concurrently the quality of our lives may be decreas-ing. Without a doubt, the modern medical advances to which we have access today are the results of decades of investment in medical research. As we age, we also learn to live with such inconveniences of modern life despite the fact the society is driven by the development of science and technology. That is the reality of life.Obviously there are challenges ahead. Sleep disorders are highly prevalent in the general population, and not only repre-sent direct personal health problem, but indirectly affect health by increasing the risk of accidents which can bring harm to the affected individual as well as to those around him (Institute of Medicine Report, 2006; Pandi-Perumal et al., 2006). Up to 50% of older persons in Western societies complain of sleep disturbances, includ-ing the quality and quantity of sleep (e.g., frequent awakenings, disturbances to the sleep/wake cycle, and daytime sleepiness) (Vitiello, 2006). Aging is further character-ized by modifications of morphology, qual-ity, and quantity within the 24 h sleep/wake architecture. Sleep specialists continue to debate whether or not older individuals need less sleep. Despite the many efforts to resolve this problem, the question remains: what are the ideal characteristics of “nor-mal” sleep in the elderly. Studies have shown that the ability to sleep decreases with age (Pandi-Perumal et al., 2002; Ancoli-Israel, 2009). This raises the following question: Is this reduction in sleep ability a natural part of aging or does it result from other comorbid conditions that develop as peo-ple age? Collectively, published studies support the view that sleep disturbances are not directly related to age. Sleep com-plaints in older adults are often associated with medical and psychiatric comor-bidities rather than the fact of aging itself (Vitiello et al., 2002; Foley et al., 2004). In the absence of comorbidities, older adults usually have few changes in sleep char-acteristics. Poor sleep in the elderly is a major health problem because it has been linked to serious consequences including poor physical and mental health (Paudel et al., 2010). Poor sleep may be associated with the prodormal phase of a disease, as a prominent complaint and/or exacerbation of the symptoms of a particular disease. A significant association between poor sleep and falls has been confirmed by a number of studies (Avidan et al., 2005; Stone et al., 2008). In addition, a significant association between sleep disturbances and increased mortality in the elderly has been reported (Dew et al., 2003; Paudel et al., 2010). Therefore, it is very important to recognize and treat sleep disturbances and the associ-ated medical and psychiatric disorders in this group of patients (Avidan and Alessi, 2008; Pandi-Perumal et al., 2010; Pigeon and Matteson-Rusby, 2010).In this issue of