Open Access
CC BY-NC-ND 4.0 · Sleep Sci 2024; 17(S 01): S1-S89
DOI: 10.1055/s-0045-1811782
Sleep Science Supplement 2024

The Influence of Chronotype and Regularity on Social Jetlag and Sleep Quality of Unicamp Medical Students

Authors

  • Thiago Hideki Shimoura de Oliveira

    1   Universidade Estadual de Campinas, Campinas, SP, Brazil

  • Victor Sanz Milone

    1   Universidade Estadual de Campinas, Campinas, SP, Brazil

  • Andrea Maculano Esteves

    2   Universidade Estadual de Campinas, Limeira, SP, Brazil
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Keywords

social jetlag - regularity - sleep quality - chronotype - medical students

Introduction: Medical students have been a group that is highly vulnerable to poor sleep quality and sleep disorders. Several factors are related to these disorders, including the high workload and the culture of medical productivity. However, there are also chronotype, and regularity, which are sleep factors that have been associated with poor sleep quality and higher levels of social jetlag, which are associated with risk factors for depression, cardiovascular diseases and metabolic syndrome.

Objective: The aim of this study was to evaluate the influence of chronotype and regularity on sleep quality and social jetlag among medical students at UNICAMP.

Methods: To conduct the research, medical students at UNICAMP from all years of graduation participated. Questionnaires were applied, such as anamnesis, chronotype questionnaires (Horne and Osterberg; Munich), subjective sleep quality questionnaire (Pittsburgh), Epworth daytime sleepiness questionnaire, international physical activity questionnaire short form, sleep regularity index and sleep diary. Study activities lasted 90 days.

Results: The results were obtained in a sample of 286 students, which showed a regular sleep efficiency (91.71±13.07), and a poor sleep quality (7.21±2.74). The results regarding latency (23.9±25.55) and efficiency (91.71±13.07) were considered within normal limits, as well as the total sleep time (TST = 7:30±2.03). In addition, 82.32% of the students were active according to the physical assessment questionnaire (IPAQ). The sixth grade presented the worst sleep quality index (9.09±3.70). The students presented a chronotype profile considered intermediate (50.69±10.65). Other relevant results found were the associations between some sleep variables. Morning chronotype was associated with shorter latency time, better sleep quality and less social jetlag. An association was also found between higher values of sleep regularity with better sleep quality and less daytime sleepiness. Similarly, lower values of social jetlag were associated with better sleep quality.

Conclusion: It is suggested that greater sleep regularity and more morning chronotype profiles act as factors to improve sleep quality and also act to reduce latency, sleepiness and social jetlag among medical students at UNICAMP. Acknowledgements: Fapesp (2023/04800-3).


No conflict of interest has been declared by the author(s).

Publication History

Article published online:
16 September 2025

© 2025. Brazilian Sleep Academy. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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