Age differences in sleep-wake behavior under natural conditions
Journal/Book: Pers Indiv Differ. 1999; 27: the Boulevard Langford Lane, Kidlington, Oxford Ox5 1GB, England. Pergamon-Elsevier Science Ltd. 853-860.
Abstract: Differences in lifestyle may account for a considerable portion of the reported age-related changes in overt circadian rhythmicity, By instructing a group of healthy, noninstitutionalized, elderly subjects and a group of young adults to keep a sleep-wake log for a period of two weeks, and to wear an activity monitor for an overlapping period of 11 days, we attempted to assess age-related differences in the habitual sleep-wake behavior. In particular its day-to-day variability. Four clusters of coherent variables were constructed, reflecting (1) circadian phase, (2) variability of sleep-wake behavior, (3) sleep-wake continuity and (4) subjective sleep-wake quality. The results showed that, in comparison with the young subjects, the elderly had a relatively advanced and more regular sleep-wake pattern, reported more midnight awakening and did not differ in their subjective sleep evaluation. In spite of a greater regularity in their lifestyle (which would favor a larger amplitude of the overt circadian rhythmicity) oral temperature measurements showed some evidence of a weakened 24-h periodicity in the elderly.
Note: Article Kerkhof GA, Univ Amsterdam, Dept Psychonom, Amsterdam, NETHERLANDS
Keyword(s): human; healthy elderly; ageing; circadian; sleep-wake rhythm; actigraphy; CIRCADIAN-RHYTHMS; PERSONALITY; TEMPERATURE; HUMANS; YOUNG