続発性骨粗鬆症におけるスクリーニング

Secondary osteoporosis. Clinical approach to secondary osteoporosis.

１．続発性骨粗鬆症は，何らかの基礎疾患や薬剤などを原因として，原発性骨粗鬆症と類似の骨代謝障害を生ずる病態の総称である。 ２．続発性骨粗鬆症の原因には，いくつかの内分泌疾患，栄養障害あるいは特定の薬剤によるものなどがある。 ３．教科書的な続発性骨粗鬆症の原因以外にも，２型糖尿病・慢性腎臓病（CKD）・慢性閉塞性肺疾患（COPD）などの疾患は骨折リスクを高めることが明らかになっている。 ４．続発性骨粗鬆症では原発性骨粗鬆症よりも性差が少ないので，男性でも注意が必要である。 ５．骨軟化症などの骨粗鬆症の病態とは異なる骨粗鬆症類縁疾患については，その存在を知り正しく鑑別することが大切である。

　Osteoporosis is deterioration of bone integrity caused by bone loss（bone mineral density decrease）due to failure of coupling of bone resorption and bone formation. Various pathophysiological conditions other than natural menopause or aging are involved in the development of osteoporosis. When there is a specific cause of the disease, it is referred to as secondary osteoporosis. Secondary osteoporosis is usually thought to lead to an increased risk of fracture by causing a decrease in bone mineral density. It has also should be noted that in patients receiving corticosteroids, bone mineral density independent fracture risk increases. Furthermore, now we are aware of the existence of many diseases including type 2 diabetes, which contributes to an increase in the risk of fracture irrespective of bone mineral density. Unfortunately, at present, it is difficult to quantitatively evaluate the contribution of those background diseases to fracture risks, so the establishment of guidelines on intervention for fracture prevention is still awaited.