Using compositional analysis to explore the relationship between physical activity and cardiovascular health in children and adolescents with and without type 1 diabetes.

OBJECTIVE: The aim of this study was to use a compositional analysis approach to account for the inherent co-dependencies between behaviors and to explore how daily movement behaviors influence cardiovascular health in children with and without T1D. RESEARCH DESIGN AND METHODS: Augmentation index, pulse wave velocity (PWV) and heart rate variability were measured in 20 children with (11.9 ± 1.6 years) and 17 children without T1D (11.6 ± 2.2 years). Subsequently, physical activity and sleep were assessed at 20 Hz for 28 consecutive days using a wrist-worn accelerometer. Compositional analyses were utilized to explore the relative effects of each movement behavior and the overall movement complex on cardiovascular parameters, with predictive modeling used to explore the effects of reallocating 20 min between behaviors. RESULTS: Arterial stiffness markers were most influenced by the total movement composition, whereas autonomic function was most influenced by sedentary time and sleep relative to all other behaviors. Reallocation of time from moderate-to-vigorous physical activity (MVPA) to any other behavior was predicted to negatively affect all cardiovascular measures, independent of disease status, whereas reallocating time to MVPA was consistently predicted to improve all outcome measures. Additionally, the same intensity of physical activity appeared to be more potent for cardiovascular health in T1D children compared to nondiabetic peers. CONCLUSIONS: Intensity, rather than volume, of physical activity may be key in reducing risk of premature adverse changes in cardiovascular health, whereas increasing time in MVPA could potentially the slow progression of cardiovascular aging in children with diabetes.

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 (r2 = 0.89, r2 = 0.80, r2 = 0.79, respectively; all p < 0.05), while average acceleration was correlated with MVPA and bouted MVPA (r2 = 0.85, r2 = 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.

Investigating the influence of physical activity composition on arterial stiffness in youth.

Physical activity is beneficial for arterial health in children but less is known about how all daily movement behaviours influence arterial stiffening. Compositional analysis can account for the co-dependent nature of these behaviours and therefore was employed to explore how the movement composition influences arterial health. Augmentation index (AIx) and pulse wave velocity were measured cross-sectionally in healthy children (n = 129; 12.4 ± 1.6 years). Time spent in sedentary, light physical activity (LPA), moderate-to-vigorous physical activity (MVPA) and asleep were derived from seven-day hip-worn accelerometry. The relative effects of individual behaviours and the overall movement composition on arterial stiffness were explored utilising compositional analysis, with predictive modelling used to predict effects of the substituting time between behaviours. Girls (n = 45, 12.1 ± 1.5yrs, 20.5 ± 3.6kg·m-2) had a higher AIx (+ 3.94; p < 0.05) and accrued physical activity predominantly in LPA, whereas boys (n = 56, 12.6 ± 1.7yrs, 20.6 ± 4.0kg·m-2) accrued physical activity predominantly in MVPA. Individual behaviours and the movement composition were not significant predictors of any measure of arterial stiffness (P > 0.05), and the reallocation of 20-minutes between behaviours did not elicit significant change in arterial stiffness, irrespective of sex (P > 0.05). The reallocation of time to MVPA from any other behaviour did not predict an improvement in arterial stiffness. This highlights the high potential dose of MVPA required to improve arterial health and the complex nature of the determinants of arterial stiffness.HighlightsMovement behaviours in isolation nor combination predicted arterial stiffness in youth.The reallocation of behaviours from any other behaviour to MVPA did not affect arterial stiffness in youth.Arterial stiffness is a complex, multidimensional health parameter that does not appear to be primarily determined by physical activity levels or intensity.