Association of physical activity metrics with indicators of cardiovascular function and control in children with and without type 1 diabetes

Objective Little is known about the role of physical activity accumulation in cardiovascular disease risk for children with type 1 diabetes. Improved insight to identify factors of influence in key health outcomes could be provided by considering the entire physical activity profile. Methods Pulse wave velocity (PWV), augmentation index and heart rate variability (HRV) were assessed cross-sectionally in children with (n = 29, 12.1 +/- 2.1 years) and without (n = 19, 12.1 +/- 2.1 years) type 1 diabetes. Time spent sedentary and in each physical activity intensity, intensity gradient and average acceleration were derived from seven consecutive days of monitoring with wrist-worn accelerometry. Comparison between groups and influence of physical activity accumulation on cardiovascular metrics were explored with linear mixed models. Results Diabetic children demonstrated a higher PWV and a greater volume of light physical activity (p < 0.01), a more negative intensity gradient (p < 0.01), a lower average acceleration and less time in bouted moderate-to-vigorous physical activity (MVPA; p < 0.05). Overall, intensity gradient was strongly correlated with average acceleration, MVPA and bouted MVPA (r(2) = 0.89, r(2) = 0.80, r(2) = 0.79, respectively; all p < 0.05), while average acceleration was correlated with MVPA and bouted MVPA (r(2) = 0.85, r(2) = 0.83, respectively; p < 0.05). Accounting for disease status, intensity gradient and average acceleration were significant predictors of HRV indices (p < 0.05) and PWV (p < 0.01, p < 0.05, respectively). Conclusion Overall, MVPA was most associated with central stiffness, highlighting the importance of meeting activity guidelines. Diabetic children demonstrated poorer cardiovascular health than their counterparts, likely attributable to a lower intensity and physical activity volume, identifying physical activity intensity as a key target for future interventions.