Association between Sedentary Time and 6-Year All-Cause Mortality in Adults: The Rural Chinese Cohort Study

This study aims to prospectively explore the association between sedentary time and the risk of all-cause mortality in adults based on a cohort from rural areas of China.

The study population included 20,194 adults at baseline (2007-2008) who participated in the Rural Chinese Cohort Study. Cox's proportional hazard regression model was used to analyze the hazard ratios (HRs) and 95% confidence intervals (CIs) of sedentary time and all-cause mortality, and a restricted cubic spline was used to model the dose-response relation. We also carried out a series of sensitivity analyses to verify the robustness of our main results.

The median follow-up duration was 6 years, with a total of 17,265 participants (response rate 85.5%) followed up, and 1,106 deaths observed. Data for 17,048 participants were analyzed, with the mean age of participants being 52.00. Compared with sedentary time <4 h/day group, the risk of all-cause mortality was significantly increased in the 8-11 h/day (HR=1.27, 95%CI:1.03-1.56) and ≥11 h/day groups (HR=1.48, 95%CI:1.20-1.84). With increases in sedentary time, the risk of all-cause mortality increased gradually (Ptrend <0.001). For each 1 h/day increase in sedentary time, the risk of all-cause mortality increased by 3% (HR=1.03, 95%CI: 1.01-1.05). Sensitivity analyses showed our main results were consistent.

Prolonged sedentary time increases the risk of all-cause mortality in the adult rural Chinese population. Reducing sedentary time may have important implications for reducing mortality risk.