Abstracts: American College of Sports Medicine Conference on Integrative Physiology of Exercise: FRIDAY, SEPTEMBER 29, 2006: POSTER SESSION 2: Cardiovascular
The purpose of this study was to examine the extent to which cardiovascular fitness, independent of confounding factors, was associated with immune responsiveness to clinically relevant challenges in older adults (60-76 years).
Thirteen sedentary, low fit (LF; VO2max = 21.1 ± 1.1 ml.Kg−1.min−1) and 13 physically active, high fit (HF; VO2max = 46.8 ± 3.4 ml.Kg−1.min−1) older adults participated in this study. Each subject was screened for health status and each performed a maximal graded exercise test with oxygen uptake assessment. Dietary intake was assessed via recall and interview with a registered dietician and a battery of psychosocial tests were administered. In vivo antibody and ex vivo proliferative and cytokine responses to influenza (Flu) and tetanus toxoid (TT) vaccination, and in vivo responses to delayed-type hypersensitivity (DTH) skin test antigens were performed.
HF elderly displayed a higher antibody response to 2 of the 3 strains included in the Flu vaccine as measured by hemagluttination inhibition, but there was no difference between HF and LF in influenza-specific ex vivo proliferation or interferon(IFN)-γ or interleukin(IL)-10 production. HF elderly also exhibited a lower IgG1 and a tendency for a higher IgG2 response to the TT vaccine. There were, however, no differences in TT-specific ex vivo proliferation or IFN-γ or IL-10 production. In contrast, HF subjects had higher proliferative responses to phytohemagluttinin. Lastly, there were no differences in DTH responses to fungal antigens between fitness groups.
These results suggest that, after accounting for confounding factors, HF elderly have higher antibody responses to Flu vaccine and a Th2 skewing of the antibody response to TT. There was little evidence that HF elderly subjects mounted better cell-mediated immune responses to the Flu or TT vaccine or to other recall antigens.