SLEEP CHARACTERISTICS OF NORMAL AGED MALE

In order to study the sleep characteristics of the normal elderly male, 16 volunteers aged 71 to 95 years (mean age, 80.2), slept in the laboratory for at least 2 or 3 base line nights each. Age correlated positively (r = .64, p < .01) with number of awakenings and negatively (r = -.43, .05 < p < .1) with percentage of time asleep, indicating increasing sleep disturbance between the ages of 71 and 95 years. Mean rapid eye movement sleep (REM) percentage was 20.1; total REM time, 74 minutes; and mean REM period length, 17 minutes. Age correlated negatively with each of these measures (-.50, -.47 and -.51, respectively, all p < .05); however, REM sleep did not appear markedly reduced until late old age. Mean percentage of stage 4 sleep was 4.5 and stage 3, 17.2. In comparison to the young adult, stage 4 sleep appeared decreased and stage 3 sleep, increased. The amplitude of delta waves in the aged was reduced, a finding which probably contributed to the lowered amounts of stage 4 sleep. The latency from sleep onset to the first REM period in the elderly seemed shortened. This reduced latency probably resulted from decreased stage 4 sleep during the first non-REM period. REM sleep increased in the latter part of the night, and this was due to decreased intervals between REM periods and not to increased REM period lengths. Finally, with increased age there were more frequent interruptions of REM periods by stretches of stage 2 sleep. © Williams & Wilkins 1969. All Rights Reserved.