続発性骨粗鬆症の原因と病態

Secondary Osteoporosis or Secondary Contributors to Bone Loss in Fracture. Causes and pathophysiology of secondary osteoporosis.

　続発性骨粗鬆症は骨粗鬆症を惹起する特定の原因を有する場合を称し，多くの疾患や薬剤，栄養障害などが原因となる。続発性骨粗鬆症は原疾患の治療により，劇的に改善するため，原発性骨粗鬆症の診断時に続発性骨粗鬆症を鑑別することは極めて重要である。続発性骨粗鬆症はそれぞれ原因となる病態が異なるため，骨折リスクにおける低骨密度の関与も様々である。薬剤性続発性骨粗鬆症は原疾患に対する治療薬の副作用によるものであり，治療開始と同時に薬剤の骨への影響を回避すべき対応を要する。ステロイド性骨粗鬆症と同様に，性腺機能抑制療法における骨粗鬆症への対応については認知されてきている。

　Cases of osteoporosis that have a specific cause are defined as secondary osteoporosis. Secondary osteoporosis may be caused by various diseases and drugs, malnutrition, and other factors. Because secondary osteoporosis can be dramatically improved by treating the primary disease, it is extremely important to differentiate secondary osteoporosis at the time of diagnosis of primary osteoporosis. Because the pathophysiological condition that causes secondary osteoporosis varies by case, the degree to which low bone mineral density is involved in fracture risk also varies. Drug-induced secondary osteoporosis is caused by the side effects of treatment drugs used for the primary disease, and its management requires initiation of treatment with simultaneous prevention of the effects of drugs on bone. As with glucocorticoid-induced osteoporosis, there is an increasing awareness that simultaneous management of osteoporosis is necessary when performing estrogen or androgen deprivation therapy.