Association between device-measured physical activities, type 2 diabetes, and life expectancy over the next 10 years:...

The mediation effect of 24-hour physical activities on the association between type 2 diabetes and mortality is unclear. Additionally, Little evidence was found on the isotemporal substitution effect of 24-hour physical activities components on changing Life expectancy among patients with type 2 diabetes diagnosed. To address the abovementioned research gap, the study has a two-fold aims: first, to examine the mediation effect of 24-hour physical activities in type 2 diabetes and mortality; and second, to address how reallocating time on different daily activities would affect life expectancy.

Analysis was conducted on the accelerometer data of 103,359 participants in the UK Biobank, with a median age of 57 years (range 39 to 70). Compositional mediation cox model was conducted to analyze the mediating effects of 24-hour physical activities. Additionally, the cohort Life table method was utilized to estimate the changes of Life-years over the next 10 years resulting from the substitution effect of different physical activities.

During a mean follow-up of 13.95 (range 2.95-16.28) years, 2,649 deaths were recorded. Diabetes was significantly associated with increased time spent engaging in sedentary behavior (SB), and reduced time spent on moderate-to-vigorous physical activity (MVPA) and light-intensive physical activity (LPA), thereby demonstrating an association with higher mortality risk. The indirect effect of physical activity (HR = 1.27, 95% CI 1.23-1.30) accounted for 41.9% of the total effect of diabetes on mortality. Furthermore, the Life expectancy gains with a maximum of 1.32 years over the next 10 years was found when reallocating SB time to MVPA.

The results revealed that 24-hour physical activities might mediate the association between diabetes and mortality. Therefore, promoting participation in MVPA and reducing sedentary activities among diabetes patients was expected to have a positive effect on Life expectancy over the next 10 years.