Chronotype in bipolar disorder: Differences in sleep quality, social jet lag, physical activity, and diet

Abstract

Introduction. People with bipolar disorder are at a higher risk of metabolic morbidity and mortality. Chronotype may play a significant role due to its effect on sleep quality, eating patterns, and physical activity. Objective. To compare sleep quality, social jetlag, physical activity, and diet, depending on the chronotype of people with bipolar disorder, and to determine the association between these variables. Method. Cross-sectional, comparative, correlational study. The sociodemographic and clinical characteristics of subjects were assessed. Chronotype was determined using the Composite Scale of Morningness while sleep quality was evaluated through the Pittsburg Sleep Quality Index. Social jet lag was calculated through the absolute difference between the midpoint of sleep on weekends and workdays. Physical activity was measured through the Bouchard Activity Record and diet was evaluated through a food frequency questionnaire. Comparative analyses were performed between chronotype categories and the association between variables was measured. Results. 116 subjects were included. Subjects with evening chronotype reported poorer sleep quality than those with morning chronotype. Eveningness was associated with lower sleep quality scores and more hours of sleep on workdays, as well as with higher consumption of cold meats, calories, and sodium. Trends indicate greater social jet lag and low physical activity levels among evening chronotypes. Discussion and conclusion. The effects of chronotype on study variables require further research to clarify this complex relationship and develop educational strategies to promote sleep hygiene, physical activity, and a healthy diet.