Impact of regular moderate aerobic exercises in delaying immunosenescence in elderly people

Increase of life expectancy is a global event and has changed the population pyramid, with increasing elderly population and reducing young population, both in developed and developing countries. According to the United Nations in the 2012 Revision of the World Population Prospects, the Brazilian elderly population will reach 50 million people in 2050. Aging leads to marked detrimental changes in the composition, function, and competence of the human immune system, a phenomenon termed immunosenescence. These changes are associated with increased incidence and severity of infections, poor vaccine efficacy, and possibly the developing autoimmunity and cancer. Immunosenescence is associated with decreased number of naïve T cells and increased of memory T cells, loss of CD28 costimulatory molecule, telomere shortening and Inflamm- aging. In Brazil, the increase in the elderly population and the consequent increased demand for health care will encumber the Sistema Único de Saúde. Thus, the study of interventions to attenuate the immunosenescence is highly relevant. A possible intervention that has been studied is physical activity. However, the majority of studies evaluated the acute impact of physical activity or assessed the impact of short periods of chronic physical activity. The aim of this study was to evaluate the impact of regular moderate aerobic exercises in delaying immunosenescence in elderly people. Thirty one elderly men (65-85 years) were divided in two groups, one with history of moderate regular physical activity for 15 ( ± 3) years and the other without history of physical activity, were evaluated for percentage of CD4+ and CD8+ naïve and memory T cells, loss of CD28 costimulatory molecule, telomere length, lymphocyte proliferation, apoptosis markers, cytokine synthesis (TH1/TH2), serum levels of inflammatory cytokines and anti-influenza antibodies production. The groups were comparable regarding age, cognitive and functional abilities and body mass index. All elderly had good nutritional status and did not have depression. The moderately trained elderly had a higher weekly caloric expenditure (increase in METs, p < 0.0001) and a higher maximal oxygen uptake (VO2max, p < 0.001), showing its higher fitness. The moderately trained elderly had a higher percentage of TMC lymphocytes and lower frequency of Temra lymphocytes, higher lymphoproliferative responsiveness of CD8 + T lymphocytes stimulated with mitogen, lower expression of apoptosis markers in the subpopulation of T CD8 + CD28neg cells and production of higher titles serum anti-influenza antibodies before and after immunization. The data showed that the practice of regular moderate physical activity as a lifestyle contributed to reduce of the some typical features of immunosenescence (AU)