"As we age, the internal clock that coordinates our physiology with the 24-hour day falters. New research provides the first glimpse at molecular changes that underlie the mistiming. The results suggest that aging disrupts the connection between the brain's central clock and timekeepers elsewhere in the body.
"Sleep problems, which commonly trouble the elderly, aren't just an annoyance. Lack of sleep can impair memory, disrupt metabolism, and perhaps even hasten death. In addition, disjointed internal clocks prompt many Alzheimer's patients to do things at inappropriate times, "like making breakfast at 3:00 in the morning," says molecular biologist Christopher Driver of the National Ageing Research Institute in Melbourne, Australia."
Healthy Older Adults' Sleep Predicts All-cause Mortality at 4 to 19 Years of Follow-up. Dew MA, Hoch CC, Buysse DJ, Monk TH, Begley AE, Houck PR, Hall M, Kupfer DJ, Reynolds CF 3rd. Psychosomatic Medicine 2003; 65(1):63-73
"CONCLUSIONS: Older adults with specific EEG sleep characteristics have an excess risk of dying beyond that associated with age, gender, or medical burden. The findings suggest that interventions to optimize and protect older adults' sleep initiation, continuity, and quality may be warranted."
Circadian and Age-Related Modulation of Thermoreception and Temperature Regulation: Mechanisms and Functional Implications Eus J. W. Van Someren, Roy J. E. M. Raymanna, Erik J. A. Scherder, Hein A. M. Daanen and Dick F. Swaab. Ageing Research Reviews 2002, 1(4):721-778.
"At older ages, the circadian rhythm of body temperature shows a decreased amplitude, an advanced phase, and decreased stability. Given the functional significance of the temperature rhythm, research should focus on the feasibility and effectiveness of methods that can in principle be applied in order to enhance the weakened circadian temperature rhythm in the elderly."