COPD as a systemic disease.

Chronic obstructive pulmonary disease (COPD) represents an important and increasing burden throughout the world. Classically, COPD has been considered a respiratory condition only, mainly caused by tobacco smoking. However, COPD has important manifestations beyond the lungs, the so-called systemic effects. These include unintentional weight loss, skeletal muscle dysfunction, an increased risk of cardiovascular disease, osteoporosis, and depression, among others. Low-grade, chronic systemic inflammation is one of the key mechanisms underlying these systemic effects. Because these extra-pulmonary manifestations of COPD are common and/or may have significant implications for the patient wellbeing and prognosis, they warrant systematic screening and appropriate management in order to provide optimal medical care.