[Secondary osteoporosis]

Involutional osteoporosis is one of the most prevalent diseases all over the world. Some osteoporotic patients, however, suffer from a co-existent disease that causes or accelerates development of osteoporosis. In contrast to primary osteoporosis, such "secondary" osteoporosis is more common in men. Recent studies have, revealed that more and more diseases and drugs increase fragility fractures. Such a comorbidity is often a weak risk factor by itself rather than "a cause" of osteoporosis, but sometimes multiple risk factors are found in a single patient. It is therefore important for physicians to evaluate and integrate such risk factors for clinical decisions. In this review, I will summarize secondary causes of osteoporosis and discuss a pathophysiological link between cardiovascular disease and osteoporosis as an example.