Objective: Chronotype refers to an individual’s natural preference for sleep and wake times, which reflects their internal circadianrhythm. It determines whether a person feels more alert and active in the morning, in the evening, or follows a more intermediatepattern. The aim of the study was to identify a potential association between chronotypes and the consumption of nicotine and highriskalcohol use among medical students.Materials and Methods: The study was conducted between May 2024 and June 2024 via an online platform (Google Forms) amongmedical students in Marmara University.
Horne-Ostberg’s Morningness-Eveningness Questionnaire form was used to determine thecircadian rhythm characteristics. Univariate and multivariate analyses were performed to determine the associations of nicotine andhigh-risk alcohol use with chronotype.Results: A total of 323 medical students participated in the survey.
Of the respondents, 198 (61.3%) had an intermediate chronotype,69 (21.4%) had a morning chronotype, and 56 (17.3%) had an evening chronotype. It was observed that students with an eveningchronotype had a statistically significantly higher rate of regular nicotine use compared to those with a morning chronotype (OR=3.62,p=0.04) and a high-risk alcohol use (OR=4.49, p=0.015).Conclusion: Assessing the evening type population among medical students may be a specific target for educational health promotioninterventions aimed at preventing or reducing alcohol and nicotine consumption.