0216 The Effect Of Caffeine On Glucose Metabolism, Self-reported Hunger And Mood State During Extended Wakefulness

Abstract Introduction Caffeine is a stimulant often taken to reduce sleepiness and improve cognitive performance. The effect of caffeine on glucose metabolism during sleep deprivation is less well understood. This double-blind laboratory study examined the impact of caffeine on glucose metabolism, self-reported hunger and mood state during 50h of wakefulness. Methods Participants were assigned to caffeine (n=9, 6M, age 21.3 ± 2.1y; BMI 21.9 ± 1.6kg/m2) or placebo conditions (n=8, 4M, age 23.0 ± 2.8y; BMI 21.8 ± 1.6kg/m2). Following a baseline sleep opportunity from 22:00h-08:00h, participants commenced 50h of extended wake. Caffeine (200mg) or placebo gum was administered at 01:00h, 03:00h, 05:00h and 07:00h during each night of extended wake. Continual glucose monitoring was used to capture interstitial glucose 2h post-breakfast, from which area under the curve (AUC) was calculated. Hunger and mood state were assessed at 10:00h, 16:30h, 22:30h and 04:30h. Results A significant rise in glucose AUC, in response to breakfast, was seen following the second night of extended wakefulness (p=0.003, ɳ2partial=0.32, large effect). Caffeine did not alter the glucose response, with no difference shown between conditions (p=0.680, ɳ2partial=0.01, small effect). Participants reported significant (p