Effect of cardiorespiratory fitness on acute inflammation induced increases in arterial stiffness in older adults.

We tested the hypothesis that acute inflammation may cause arterial stiffening in older adults. We further explored if high cardiorespiratory fitness may partially prevent the unfavorable effect of arterial stiffening produced by acute systemic inflammation in older adults. Using a randomized double-blind sham placebo-controlled design, forty healthy older adults were assigned to receive either an influenza vaccine or a sham vaccine. C-reactive protein and interleukin 6 (IL-6) were measured as markers of inflammation. Carotid-femoral pulse wave velocity (PWV) and augmentation index (AIX) as indices of arterial stiffness and wave reflection were assessed at baseline and 24 and 48 h after each vaccination. When compared with sham placebo, the influenza vaccination caused a significant increase in CRP (p < 0.05) and IL-6 (p < 0.05). Carotid-femoral PWV, but not AIX was significantly increased after influenza vaccination (p < 0.05), but not sham vaccination. The high cardiorespiratory fitness group had an attenuated increase in PWV as compared to the low cardiorespiratory fitness group after acute inflammation (p < 0.05). These findings show that acute inflammation may cause significant increases in arterial stiffness in older adults, but these increases were attenuated in the high cardiorespiratory fitness group as compared to the low cardiorespiratory fitness group.