Age-related ventricular-vascular coupling during acute inflammation in humans: Effect of physical activity

Background: Aging is commonly accompanied by increased arterial and ventricular stiffness (determined by arterial elastance (Ea) and ventricular elastance (Elv)), augmented ventricular-vascular coupling ratios (Ea/Elv) and systemic inflammation. Acute inflammation may impact ventricular-vascular coupling and predispose older adults to cardiovascular events. However, physically active older adults have more compliant large arteries and left ventricles and lower inflammation than sedentary older adults. We hypothesized that acute inflammation would alter Ea, Elv, and Ea/Elv more in older versus younger adults but that higher levels of physical activity would attenuate inflammation-induced changes. Methods: End-systolic and central blood pressures were obtained using applanation tonometry before and at 24 and 48 h post-influenza vaccination in 24 older and 38 younger adults. Ultrasonography was used to measure ventricular volumes and other indices of cardiac performance. Physical activity was measured with accelerometry. Results: Ea and Ea/Elv were maintained (p > 0.05), but Elv was reduced (p < 0.05) 24 h post-inflammation. Other indices of systolic performance were reduced in older but not younger adults; diastolic performance was attenuated in both groups 24 h post-inflammation (p < 0.05 for all). Older, but not younger, adults decreased central pressure during inflammation (p < 0.05). When controlled for age, physical activity was not related to the inflammation-induced changes in elastance (p > 0.05) except in the most active group of seniors (p < 0.05). Conclusions: Aging did not affect the elastance responses but did affect central blood pressure and other ventricular systolic responses to acute inflammation. Aging, not physical activity, appears to modulate cardiovascular responses to acute inflammation, except in the most active older adults.