Indexed on: 29 May '14Published on: 29 May '14Published in: Journal of caffeine research
Objectives: The aims of this study were to evaluate patterns of circadian preferences and daytime sleepiness, and to examine the extent to which the consumption of stimulant beverages is associated with daytime sleepiness and evening chronotype among Peruvian college-age students. Methods: A total of 2,581 undergraduate students completed a self-administered comprehensive questionnaire that gathered information about sleep habits, sociodemographic and lifestyle characteristics, and the use of caffeinated beverages. The Morningness-Eveningness Questionnaire (MEQ) and Epworth Sleepiness Scale (ESS) were used to assess chronotype and daytime sleepiness. We used multivariable linear and logistic regression procedures to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for the associations of sleep disorders with sociodemographic and behavioral factors. Results: The prevalence of daytime sleepiness was 35% [95% CI 32.7-36.4] and eveningness chronotype was 10% [95% CI 8.8-11.1%]. Age, sex, cigarette smoking, and alcohol consumption were significantly associated with an evening chronotype. After adjusting for age, sex, smoking, body mass index, and physical activity, students who reported consumption of any stimulant beverages had 1.25 increased odds of excessive daytime sleepiness (OR=1.25 [95% CI 1.03-1.53]) compared with students who did not consume stimulant beverages. Consumption of any stimulant beverages was not statistically significantly associated with being an evening chronotype (OR=1.30 [95% CI 0.86-1.96]). Conclusions: Excessive daytime sleepiness and eveningness chronotype are common among Peruvian college students. MEQ scores were associated with age, sex, smoking, and alcohol consumption. Regular stimulant beverage consumption tended to be positively associated with excessive daytime sleepiness.