MULTIPLE SLEEP LATENCY TEST MEASURED DAYTIME SLEEPINESS AND PERFORMANCE UNDER SLEEP RESTRICTION AND EXTENSION CONDITIONS

Daytime sleepiness in adolescents is associated with impaired physical, mental and neurobehavioral functioning. We used available data from a large ongoing study to investigate the effects of sleep restriction and sleep extension on age-related changes in daytime sleepiness and performance. All participants (18 and 24 years; 6 subjects/group) completed two time-in-bed (TIB) schedules: 7 days of habitual TIB, 3 days of 8.5h TIB, and 4 days of either 7h TIB (sleep restriction) or 10h TIB (sleep extension). On the day following the polysomnographic recording night of each TIB schedule, the Psychomotor Vigilance Test, Karolinska Sleepiness Scale (KSS), and Multiple Sleep Latency Test (MSLT) were administered four times at two-hour intervals. MSLT latency differed by TIB (8.5min for 7h TIB vs. 11.8min for 10h TIB, p<.05) and MSLT session (p<.001). Neither age nor age by TIB interaction was significant. The longest MSLT latency occurred during the first session in both groups and TIB conditions. KSS-measured subjective sleepiness did not differ by age. Performance measures showed a trend toward better performance in older group. Reaction time correlated with MSLT latency under sleep restriction condition, and showed a trend under sleep extension. TIB effect on MSLT latency indicates an effective experimental design. Findings of both objective and subjective sleepiness suggests a stable daytime sleep propensity across 18-24 years. Follow-up data spanning a wider age range would provide better insights into whether the adolescent increase in daytime sleepiness remains elevated or declines in young adulthood, and into its primary causes.
Support: SRNSF Grant FR-23-7109