Abstract
Physical activity is associated with reduced cardiovascular disease risk. However, improvements in conventional risk factors due to physical activity do not explain its full benefit. Therefore, we examined associations of objectively measured physical activity energy expenditure and intensity with central hemodynamics to provide new insight into the link between physical activity and cardiovascular disease. We analyzed data from 1816 Danes (median age: 66 years) without cardiovascular disease. Physical activity was estimated using combined accelerometry and heart rate monitoring. Aortic stiffness was assessed by applanation tonometry, as aortic pulse wave velocity, and central blood pressure was estimated from radial waveforms. Associations between physical activity energy expenditure and central hemodynamics were examined by linear regression. Furthermore, the consequence of substituting 1 hour sedentary behavior with 1 hour light or moderate-to-vigorous physical activity on central hemodynamics was examined. Median physical activity energy expenditure was 28.0 kJ/kg/d (IQR: 19.8; 38.7). A 10 kJ/kg/d higher energy expenditure was associated with 0.75% lower aortic pulse wave velocity (CI: -1.47; -0.03). Associations with central systolic blood pressure and central pulse pressure were not statistically significant. We observed no difference in central hemodynamics when substituting 1 hour sedentary behavior with 1 hour light or moderate-to-vigorous physical activity. In this relatively inactive population, higher physical activity energy expenditure was associated with lower aortic stiffness, while there was no statistically significant association between substitution of activity intensity and central hemodynamics. This suggests that lower aortic stiffness is one of a number of health benefits attributed to higher habitual physical activity.