Author(s): YUN, S., YOUNGHWAN, C., YEON SOO, K., Institution: SEOUNL NATIONAL UNIVERSITY, Country: KOREA, SOUTH, Abstract-ID: 925

INTRODUCTION:
Sedentary time (ST) has been recognized as an independent health risk factor, regardless of moderate-to-vigorous physical activity (MVPA). Although the relationship between sedentary time and a higher risk of mortality has been found in earlier research, only a few studies have examined the combined effects of ST and MVPA on mortality risk. Thus, the purpose of this study was to investigate the association of ST and MVPA with all-cause mortality.
METHODS:
We analyzed data from 8,568 Korean adults who participated in the 2014-2015 Korea National Health and Nutrition Examination Survey (KNHANES). During follow-up through 2019, a total of 172 deaths were documented. Cox proportional hazard model was used to examine the associations of ST and MVPA on mortality. To determine the risk of mortality associated with ST and MVPA, ST was categorized into 6 groups (<4, 4-6, 6-8, 8-10, 10-12, >=12 hr/day) and MVPA was categorized into 3 groups (0, 1-149, >=150 min/wk of MVPA). In combined analysis, participants were categorized into 6 groups based on their level of SB (<8, 8-12, >=12 hr/day) and MVPA (<150, >=150min/wk). Reference group was defined as SB <8 hr/day and MVPA >=150min/ wk.
RESULTS:
The longest ST (>=12 hr/day) was associated with a significantly increased risk of mortality (HR = 2.10, 95% CI 1.20-3.67). Conversely, increasing levels of physical activity were associated with a decreased risk of mortality (HR = 0.64, 95% CI 0.43-0.94 for insufficient activity; HR = 0.58, 95% CI 0.40-0.82 for active group). When examining the combined effects of ST and MVPA on mortality , we observed a progressive increase in mortality risk with higher sedentary group, particularly among those with insufficient activity (HR = 1.90 95% CI 1.18-3.05 for 8-12 hr/day; HR = 2.63, 95% CI 1.61-4.27 for >=12 hr/day). However, individuals who were sufficiently active (>=150 min/wk of MVPA) were not associated with a higher risk of mortality, regardless of their ST.
CONCLUSION:
Our findings suggest that adhering to current physical activity guidelines (>=150min/wk of MVPA) may attenuate the higher risk of mortality associated with high sedentary time. These results highlight the importance of incorporating sufficient MVPA to counteract the detrimental effects of prolonged ST.
This study was funded by the Shenzhen Research Fund [JCYJ-20230807-14041-4029].