Impact of daily caffeine intake and timing on electroencephalogram-measured sleep in adolescents.

Study Objectives: Caffeine use is ubiquitous among adolescents and may be harmful to sleep, with downstream implications for health and development. Research has been limited by self-reported and/or aggregated measures of sleep and caffeine collected at a single time point. This study examines bidirectional associations between daily caffeine consumption and electroencephalogram-measured sleep among adolescents and explores whether these relationships depend on timing of caffeine use.

Methods: Ninety-eight adolescents aged 11-17 (mean =14.38, standard deviation = 1.77; 50% female) participated in 7 consecutive nights of at-home sleep electroencephalography and completed a daily diary querying morning, afternoon, and evening caffeine use. Linear mixed-effects regressions examined relationships between caffeine consumption and total sleep time, sleep-onset latency, sleep efficiency, wake after sleep onset, and time spent in sleep stages. Impact of sleep indices on next-day caffeine use was also examined.

Results: Increased total caffeine consumption was associated was increased sleep-onset latency ( = .13; 95% CI = .06, .21; < .001) and reduced total sleep time ( = -.17; 95% confidence interval [CI] = -.31, -.02; = .02), sleep efficiency ( = -1.59; 95% CI = -2.51, -.67; < .001), and rapid eye movement sleep ( = -.12; 95% CI = -.19, -.05; < .001). Findings were driven by afternoon and evening caffeine consumption. Reduced sleep efficiency was associated with increased afternoon caffeine intake the following day ( = -.006; 95% CI = -.012, -.001; = .01).

Conclusions: Caffeine consumption, especially afternoon and evening use, impacts several aspects of adolescent sleep health. In contrast, most sleep indicators did not affect next-day caffeine use, suggesting multiple drivers of adolescent caffeine consumption. Federal mandates requiring caffeine content labeling and behavioral interventions focused on reducing caffeine intake may support adolescent sleep health.

Citation: Lunsford-Avery JR, Kollins SH, Kansagra S, Wang KW, Engelhard MM. Impact of daily caffeine intake and timing on electroencephalogram-measured sleep in adolescents. . 2022;18(3):877-884.