Effects of the Adenosine Deaminase Polymorphism and Caffeine Intake on Sleep Parameters in a Large Population Sample

Study Objectives: To evaluate the association between the adenosine deaminase polymorphism, sleep architecture, and caffeine consumption. Design: Genetic association study. Setting: NA Patients or Participants: 958 participants who underwent polysomnography and genotyping. Interventions: NA Measurements and Results: Individuals carrying the A allele who consumed caffeine in the day prior to polysomnography demonstrated higher sleep efficiency and REM sleep percentage, after adjustment for potential confounders. No effect was observed in the absence of caffeine. Conclusions: Our data support the role of the ADA G22A polymorphism in sleep, and demonstrate for the first time that caffeine may act as a modulator of its functional effects.