COPD, bone metabolism, and osteoporosis.

COPD and osteoporosis are strongly associated because of common risk factors such as age, smoking, and inactivity. In addition, COPD-related systemic inflammation, vitamin D deficiency, and the use of systemic corticosteroids enhance ongoing bone destruction. Osteoporosis, in turn, may cause fragility fractures, which further impair mobility and increase morbidity and mortality. Vertebral compression fractures and rib cage fractures in patients with COPD may also reduce pulmonary function or enhance exacerbations. Early prevention and treatment of osteoporosis in COPD is, therefore, important and should be based on integrated risk assessment tools such as FRAX, which take bone mineral density, history of fragility fractures, and population-specific clinical factors into account. As long as intervention studies focusing on the bone in COPD are lacking, a more rigorous application of existing treatment guidelines of osteoporosis in general is mandatory.