[3a1101-03] 介護予防・健康づくり／口頭発表①

9:30 AM - 9:44 AM JST(12:30 AM - 12:44 AM UTC)

[14介-口-02] Carbon dioxide exposure effect on daytime sleepiness, evidence from the multiple sleep latency testCarbon dioxide exposure and daytime sleepiness

*Jin Ruinian^1,2 (1. Faculty of Sports Science., Univ. Sendai, Sendai, Japan, 2. Department of Medicine and Science in Sports and Exercise)

The aim of this paired crossover study was to examine whether carbon dioxide (CO₂) exposure induces daytime sleepiness, as measured by the multiple sleep latency test (MSLT). Eleven healthy participants completed a four-nap MSLT in the environmentally controlled chamber under two groups: the CO₂ group (4851±229 ppm) and the Control group (1102±204 ppm). The subjective sleepiness level and cognitive performances were also evaluated using the Stanford Sleepiness Scale questionnaire, Psychomotor Vigilance Test, and Stroop test after each nap session. A significant reduction in sleep latency was observed in the CO₂ group (Control vs. CO₂ = 13.1±3.3 min vs. 9.7±3.2 min). The subjective sleepiness scores were also significantly higher in the CO₂ group than in the Control group (Control vs. CO₂ = 2.7 ± 0.5 vs. 4.7 ± 0.8). Cognitive responses after naps showed no significant difference across conditions. Exposure to environmental CO₂ at a concentration as high as the upper safety limit at work sites significantly shortened the sleep latency and enhanced subjective sleepiness during naps in the MSLT without affecting cognitive responses after each exposure. Our results demonstrated that exposure to high environmental CO₂ induces daytime sleepiness that potentially compromises work efficiency and safety.