The association of physical activity and sleep duration with incident anxiety symptoms: A cohort study of 134,957 Korean adults

Background: Maintaining adequate levels of sleep and physical activity (PA) as self-help for the prevention of new-onset anxiety symptoms is becoming more important. Methods: A cohort study was performed with 134,957 adults, free of anxiety symptoms at baseline who underwent at least two comprehensive health screening examinations between 2012 and 2017. At baseline, the amount of PA was measured using the International Physical Activity Questionnaire-Short Form and sleep duration per day was assessed using a self-report questionnaire. The study's end point was new-onset anxiety symptoms, defined as a Beck Anxiety Inventory score of >= 19. Results: During 361,969 person-years of follow-up, 5086 participants developed case-level anxiety. Compared with a reference (0-600 METs-min/wk), a U-shaped relationship was observed between PA and case-level anxiety. The most beneficial levels of PA for reducing incident anxiety symptoms were higher in men than women (men: 1800-3000 METs-min/wk HR, 0.88 [95% CI, 0.78-0.81], 3000-6000 METs-min/wk HR, 0.81 [95% CI, 0.70-0.93]; women: 600-1,200 METs-min/wk HR, 0.86 [95% CI, 0.76-0.98]). In comparison with a reference ( < 6 h), the relationship between sleep duration and case-level anxiety also had a U-shaped pattern. The optimal sleep duration for decreasing the onset of case-level anxiety was 7-8 h, regardless of sex (men: HR, 0.75 [95% CI, 0.63-0.90]; women; HR, 0.61 [95% CI, 0.54-0.70]). Limitations: PA, sleep duration, and anxiety symptoms were measured using self-report questionnaires. Conclusions: The results of this study revealed the appropriate levels of PA and total sleep time for reducing incident anxiety symptoms.