Markers of systemic involvement in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is an important cause of morbidity and mortality worldwide. It is primarily a pulmonary disease, but it has various extrapulmonary manifestations such as muscular dysfunction and hypotrophy, cachexia or cardiovascular complications. That is why COPD may be considered a systemic disease. Principal mechanisms implicated in these extrapulmonary determinations are systemic inflammation, oxidative stress and neurohormonal activation. Circulating markers involved in these mechanisms can be detected in patients with COPD. We present some of the most important markers of systemic inflammation, oxidative stress and neurohormonal activation and also the clinical implications.