The anti-inflammatory effect of exercise: its role in diabetes and cardiovascular disease control.
Chronic low-grade systemic inflammation is a feature of chronic diseases such as cardiovascular disease and type 2 diabetes. Regular exercise offers protection against all-cause mortality, primarily by protection against atherosclerosis and insulin resistance and there is evidence that physical training is effective as a treatment in patients with chronic heart diseases and type 2 diabetes. Regular exercise induces anti-inflammatory actions. During exercise, IL-6 (interleukin-6) is produced by muscle fibres. IL-6 stimulates the appearance in the circulation of other anti-inflammatory cytokines such as IL-1ra (interleukin-1 receptor antagonist) and IL-10 (interleukin-10) and inhibits the production of the pro-inflammatory cytokine TNF-alpha (tumour necrosis factor-alpha). In addition, IL-6 enhances lipid turnover, stimulating lipolysis as well as fat oxidation. It is suggested that regular exercise induces suppression of TNF-alpha and thereby offers protection against TNF-alpha-induced insulin resistance. Recently, IL-6 was introduced as the first myokine, defined as a cytokine, that is produced and released by contracting skeletal muscle fibres, exerting its effects in other organs of the body. Myokines may be involved in mediating the beneficial health effects against chronic diseases associated with low-grade inflammation such as diabetes and cardiovascular diseases.