A longitudinal study of the development of daytime sleepiness in children

This study aims to (i) investigate longitudinally developmental changes of diurnal variations of body temperature and sleepiness in preschool and school-age children and (ii) investigate the effect of acute 2 h sleep reduction on daytime sleepiness over a 3 year period. Three subjects were evaluated over three consecutive days: two control days and one 2 h sleep reduction day. A sleep latency test was conducted five times each day at 2 h intervals from 10.00 h, and oral temperature measured every hour. The results showed that (i) daytime sleepiness was high and decreased with increasing age, (ii) an afternoon dip occurred with pubertal development, (iii) effects of sleep loss generally increased daytime sleepiness, in particular at 10.00 h, and (iv) temperature acrophase was delayed with age.