The role of physical fitness in the relationship between depressive symptoms and chronic Inflammation in patients enrolled in cardiac rehabilitation.

摘要

Depression often accompanies cardiovascular disease and is related to increased risk of cardiovascular mortality. Inflammation is a proposed mechanism that may link depression and increased risk of mortality among cardiac patients. Depression is associated with reduced vagal control, which may lead to the nervous system's impaired ability to properly regulate inflammation. Exercise and physical fitness are associated with improved vagal control, as well as with reductions in depression, inflammation, and mortality risk. The present study examined the roles of physical fitness and vagal control in the relationship between depression and inflammation. Depression, physical fitness, indices of vagal control, and stimulated production of inflammatory cytokines (IL-6 and TNF-alpha) were assessed in 96 patients enrolled in phase-II cardiac rehabilitation. There were no overall significant relationships between depression and IL-6 or TNF-alpha. However, physical fitness appeared to have a moderating effect as depression was related to elevated stimulated production of IL-6 only among patients with lower levels of physical fitness. Depression was related to lower physical fitness, elevated body mass index, and lower age. Given that treating depression through medication or therapy has not led to reduced risk of mortality among patients with cardiovascular disease, additional emphasis on improving physical fitness in this patient population may be warranted.