The sleep of 52 healthy paid subjects (23 male) divided into three age
-bands (20-34, 35-49 and 50-70 y) were recorded at night in their home
s for a total of 190 subject-nights while following their normal daily
activities and habitual sleep-wake schedule. Then was a shortening in
both nocturnal total sleep period and total sleep time (TST) with age
, the oldest group sleeping 46 min less than the youngest. Also, the m
id-point of sleep occurred 32 min earlier in the oldest group compared
with the youngest group. The reduction in TST with age was due, in pa
rt, to increased wake periods within sleep. The youngest subjects show
ed more Movement Time which progressively decreased with age while the
amount of stage 1 increased with age. The amount of slow-wave sleep (
SWS, stages 3 + 4) was reduced, stage 4 was more than halved, while RE
M was slightly reduced with age. There were far fewer significant gend
er differences in the sleep variables: males, particularly in the midd
le and oldest age bands, had more stage 1 than females, while females
had more SWS, particularly stage 3, than males. In general, despite re
latively limited subject selection criteria, there was good agreement
with previous laboratory-based normative sleep values for the effect o
f age and gender.