Cytokines in aging and exercise

Aging is associated with increased inflammatory activity. Increased plasma levels of tumour necrosis factor (TNF)-alpha were found in centenarians age d 100 years and in individuals aged 80-81 years when compared to a young co ntrol group. Plasma levels of TNF-a were linearly correlated to plasma leve ls of interleukin (IL)-6, TNF-receptors and C-reactive protein. High levels of TNF-a were directly related to dementia and to a low blood pressure ank le-arm index, indicating generalized atherosclerosis. In hospitalized patie nts with Streptococcus pneumonia infection, aging was associated with prolo nged inflammatory activity. Similar results were found using an in vivo end otoxin challenge model in old versus young humans. Strenuous exercise induc es increased levels in a number of proinflammatory and antiinflammatory cyt okines, naturally occurring cytokine inhibitors and chemokines. Thus, incre ased plasma levels of TNF-alpha, IL-1, IL-6, IL-1 receptor antagonist (IL-I ra), TNF-receptors (TNF-R), IL-10, IL-8 and macrophage inflammatory protein (MIP)-1 are found after strenuous exercise. The cytokine response to stren uous exercise has similarities to the cytokine response to trauma and sepsi s. Therefore, in future studies, exercise is suggested as an ethically appl icable model to use in studies on mechanisms underlying the age-associated altered cytokine response.