Sleep characteristics of adolescents: a longitudinal study.
The aim of the present research was to study sleep/wake cycle parameters of adolescents and to examine biologic and social influences on their changing sleep patterns. This was a longitudinal study of sleep characteristics of a group of 66 adolescents (mean age, 13 years and 6 months). The adolescents underwent a physical examination, had their pubertal development classified according to Tanner stages, and answered a sleep questionnaire on three timepoints at 6-month intervals. Sleep onset occurred about 1.0 hr later, wake-up time about 3.0 hr later, and sleep length was 1.0-1.5 hr longer on weekends when compared with weekdays. About 60% of the adolescents reported daytime sleepiness, mainly from 8:00 a.m. to 10:00 a.m. and from 2:00 p.m. to 4:00 p.m. on school days. Morning sleepiness on school days occurred at a time of the day that corresponded to sleep on non-school days. Additionally, there was a displacement toward later hours of the wake-up time and a sleep-length increase during weekends from the first to the third timepoint. Social factors such as home conditions and scheduling of school and non-school activities did not change throughout the period of pubertal development studied. Changes of sleep patterns detected may therefore represent an ontogenetic trend along puberty.
Depto. Fisiologia e Biofísica, ICB/USP, São Paulo, Brazil.
M M
MM
Andrade
A A
AA
Benedito-Silva
S
S
Domenice
I J
IJ
Arnhold
L
L
Menna-Barreto
D000293:Adolescent; D002648:Child; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D012016:Reference Values; D012741:Sexual Maturation; D012894:Sleep Stages; D012931:Social Environment; D014851:Wakefulness