2018 Volume 7 Issue 2 Pages 121-130
This study examined the association between health-related risks and sitting time in three different domains covering a worker’s typical life. We investigated the beneficial effect of replacing sitting time with standing/walking time in the workplace using the isotemporal substitution model (ISM). The survey was administered through the Internet. We recruited 11,729 Japanese workers by approximating industry ratios based on the 2015 Japan Labor Force Survey. The sitting times of specific domains, i.e. while working (during working time), workday leisure time, and non-workday leisure time were collected by a validated questionnaire. We used multiple logistic regression analyses to determine associations between health-related risks and sitting time. Using the ISM approach, we estimated associations when we replaced sitting with standing/walking in the workplace, and included a model that examined subgroups of workers with and without exercise habits. The analyses involved 9,524 workers (43.4 ± 11.1 years). The longest sitting time (>7.7 h) while working (during working time) was associated with significant odds ratios (ORs) of diabetes (OR = 1.41, 95% CI 1.05-1.90), hyperlipidemia (1.58, 1.23-2.01) when compared to the shortest sitting time (<3.8 h). Replacing 1 h/day of sitting with an equal amount of standing/walking at the workplace was associated with a 4% decrease in risk for hyperlipidemia and 7% for heart disease. Furthermore, these results were noticeable for workers with non-exercise habits. In conclusion, this study suggests that, especially in the workplace, extended sitting time is associated with the risk of disease, and that replacing occupational sitting with standing can effectively reduce the risk of disease in workers, particularly for those with non-exercise habits.