Abstract
Aim: The study aims to explore the relationship between objectively measured physical activity (PA) timing and the cardiovascular disease (CVD) incidence, cardiovascular-specific mortality, and all-cause mortality (ACM) in type 2 diabetes mellitus (T2DM) patients. Methods: Data were obtained from the UK Biobank, a population-based prospective cohort study. From February 2013 to December 2015, the PA of the participants was objectively measured by continuously wearing an accelerometer for 7 days. CVD was defined through the International Classification of Diseases (10th Revision) codes by linking to national hospitalization data. Death data was obtained through the National Health Service Information Center. K-means cluster analysis was used to cluster patients with similar temporal activity patterns. Results: Among 3,143 adults with T2DM (mean age 65.9 years; 62.0% men), followed for a median of 7.82 years, 13.91% developed CVD, 13.53% died from cardiovascular causes, and 9.61% died from any cause. A Cox proportional hazards regression model showed that higher hourly PA was associated with lower CVD and cardiovascular mortality risk, particularly for activity accumulated between 8 am and 4 pm. Lower ACM risk was observed for activity performed throughout the day and evening, whereas elevated early-morning activity, most notably around 3 am, was linked to higher CVD and mortality risk. Cluster analysis identified three PAtiming profiles. Compared with participants exhibiting evenly distributed daytime activity (Cluster 1), those with morning activity peaks at 8-9 am (Cluster 2) or 11-12 am (Cluster 3) had substantially reduced CVD incidence {hazard ratio (HR) 0.449 [95% confidence interval (CI), 0.318-0.634] and 0.493 (95%CI: 0.363-0.670), respectively}. The ACM risk was similarly lower in clusters 2 [HR 0.625 (95%CI: 0.448-0.873)] and 3 [HR 0.548 (95%CI: 0.403-0.746)]. These associations were independent of overall PA intensity. Conclusion: Engaging in PA in the late morning or at noon is associated with a lower risk of CVD and ACM in patients with T2DM. Time-dependent PA interventions may constitute an additional benefit for managing cardiovascular and mortality risks in these patients.</p>