The Impact Of Overnight Work On Employee's Lifestyle And Health Among Korean Adults: An Age-and Sex-matched Study

The global demand for 24-hour production and services has led to a rise in overnight work, a schedule that poses various health risks to employees. However, despite the substantial body of evidence on the independent effects of physical activity (PA), sedentary behavior (SB), stress perception, and cardiometabolic risk factors (CRFs), their interactive effects remain underexplored, particularly in the context of work schedules. PURPOSE: To examine the health and lifestyle disparities between day and overnight workers, focusing on the impact of work schedules on employee health. METHODS: Data from 604 day and overnight workers (34.7% female; mean age = 43.8 ± 16.0) were analyzed using the 2018 - 2021 Korea National Health and Nutrition Examination Survey. Independent t-tests were conducted to analyze the mean differences of continuous variables. Independent t-test was conducted to analyze the mean difference of continuous variables. Moreover, multinomial logistic regression models were employed to analyze the relationship between health-related factors, lifestyle factors, and work schedules, controlling for age and sex to mitigate potential confounding effects. RESULTS: Overnight workers faced greater health risks, including sleep deprivation (weekday sleep time: Day = 6.8 ± 1.4 hours, Overnight = 6.4 ± 1.7 hours, p < 0.001) and higher levels of type 2 diabetes (HbA1c: Day = 5.7 ± 0.5%, Overnight = 5.8 ± 1.1%, p < 0.05) than day workers. Furthermore, they were less likely to hold white-collar jobs (OR = 0.43, p < 0.01), more likely to belong to lower-income groups (OR = 2.43, p < 0.01), and had higher smoking rates (OR = 2.66, p < 0.001). Regarding CRFs, particularly elevated HbA1c levels (OR = 2.11, p < 0.05), were also associated with overnight work. However, the two groups found no significant differences in PA, SB, or stress levels. CONCLUSION: These findings highlight the critical need for targeted interventions and policies to address the unique health challenges of overnight workers. Collaborative efforts from policymakers, employers, and healthcare providers are essential to support this population and mitigate the health risks associated with shift work. Supported by: This research was supported by the National Research Foundation of Korea (NRF-2021S1A5A806440412).