Comorbidities and systemic effects of chronic obstructive pulmonary disease.

Although primarily a lung disease, chronic obstructive pulmonary disease (COPD) is now recognized to have extrapulmonary effects on distal organs, the so-called systemic effects and comorbidities of COPD. Skeletal muscle dysfunction, nutritional abnormalities including weight loss, cardiovascular complications, metabolic complications, and osteoporosis, among others, are all well-recognized associations in COPD. These extrapulmonary effects add to the burden of mortality and morbidity in COPD and therefore should be actively looked for, assessed, and treated.