[Secondary osteoporosis. Chronic obstructive pulmonary disease:COPD.]

Chronic obstructive pulmonary disease(COPD), an inflammatory disease of the lung mainly caused by cigarette smoking, is a systemic disease associated with various extra-pulmonary comorbidities such as osteoporosis, ischemic heart disease and sarcopenia. Osteoporosis is one of such complications, and the prevalence of vertebral fractures in COPD is high even in early COPD stages. Loss of bone mineral density as well as deterioration of bone quality is common in COPD patients. However, the pathophysiology of bone fragility in COPD-associated osteoporosis is still incompletely understood. COPD patients are exposed to various disease-specific risk factors such as systemic inflammation, glucocorticoid use and vitamin D insufficiency/deficiency, accumulation of which leads to development of COPD-associated osteoporosis. Vitamin D repletion and timely intervention with anti-osteoporotics would be important to protect COPD patients from fracture.