Distinct sensitivity to caffeine-induced insomnia related to age

Abstract

Caffeine acts by antagonizing the effect of the endogenous homeostatic sleep factor adenosine. In the current study we aimed to evaluate the pattern of caffeine-induced insomnia and its relation to age and sex in a general population sample derived from a web survey. The sample included 75,534 participants (28.1% men) from 18 to 75 years who answered self-report questionnaires by accessing a website in Brazilian Portuguese (BRAINSTEP project). In our sample, 3620 (17.0%) men and 9920 (18.3%) women reported insomnia due to caffeine intake. Caffeine-induced insomnia increased with aging in both men and women. This difference remained after adjusting for sociodemographic, psychiatric and sleep related variables as well as caffeine intake. Women showed higher proportion of caffeine-induced insomnia than men, but this difference did not remain after controlling for covariates. Also, individuals with caffeine-induced insomnia reported poorer sleep quality, higher latency to fall asleep and a higher proportion of psychiatric diagnoses and daily use of hypnotic drugs. In conclusion, our results show an age-associated increase in caffeine-induced insomnia and poorer mental health indicators among people with caffeine-induced insomnia complaints.

Keywords: Caffeine-induced insomnia; adenosine; age.