[Comorbidities in COPD]

The comorbidities of chronic obstructive pulmonary disease (COPD) consist of all the alterations and disorders associated, for one reason or another, with this disease. These comorbidities may be causal (other diseases also caused by smoking, such as ischemic heart disease or lung cancer), a complication (pulmonary hypertension or heart failure), a concurrence (disorders related to advanced age such as hypertension, diabetes mellitus, depression or osteoarthritis) or an intercurrent process (an acute process, generally time-limited, such as a respiratory infection). Of all these comorbidities, those most frequently associated with COPD are hypertension, diabetes mellitus, infections, cancer and cardiovascular diseases. Comorbidities in COPD not only increase the social repercussions and annual cost of the disease but are also a prognostic factor for mortality in affected individuals. Indeed, in addition to respiratory failure, frequent causes of death in patients with COPD are ischemic heart disease and malignancies. The present article discusses the comorbidities of COPD with the greatest impact due to their frequency or influence on mortality. Although not precisely known, the common mechanism of all these comorbidities could be systemic inflammation and its mediators, which play an important role in the pathogenesis of COPD.