Cardiorespiratory fitness is associated with better control of latent herpesvirus infections in a large ethnically diverse community sample: Evidence from the Texas City Stress and Health Study

Regular exercise has been purported to improve immune function and prevent latent herpesvirus reactivation, which may help delay the onset of immunosenescence with advancing age. We determined the relationship between cardiorespiratory fitness (VO2max) and latent viral load in respondents of the Texas City Stress and Healthy Study (n = 1,455, 58.4 percent female; age 25–91 years). VO2max was estimated using non-exercise equations that incorporate physical activity rating, body-mass index, age and sex. VO2max was inversely associated with high serum antibody titers against the Epstein-Barr virus capsid antigen and cytomegalovirus (CMV) optical density (surrogate measure of viral load), withstanding adjustment for demographic variables (age, sex, race, education, income, smoking) and inflammation (IL-1; C-reactive protein). The VO2max and EBV relationship was strongest in Whites and Hispanics compared to Blacks, in women compared to men, and in those aged <45 years compared to those who were older. The VO2max and CMV relationship was strongest in Hispanics compared to Blacks and Whites, for those aged >65 years compared to those of younger age, but similar between men and women. VO2max was also inversely associated with high herpes simplex virus-1 antibody titers, but did not withstand adjustment for inflammation. We conclude that high levels of cardiorespiratory fitness are associated with better control of latent herpesvirus infections, advocating exercise as a viable behavioral intervention to offset age- related declines in immune function.