臨床整形外科59巻8号

2024年08月発行

境界領域/知っておきたい

COPDと骨粗鬆症

著者： 塚本学¹ 鍋島貴行¹ 荒川大亮¹ 真野洋佑¹ 岡田祥明² 沖本信和³ 酒井昭典¹

所属機関： ¹産業医科大学整形外科学教室 ²産業医科大学外傷再建センター ³沖本クリニック

ページ範囲：P.1044 - P.1047

はじめに

　2018年，全国たばこ喫煙者率調査によると，成人男性の平均喫煙率は27.8％である．喫煙率が低下傾向にある60歳以上では21.3％だが，30〜50代では依然として35％前後を推移しており，最も喫煙率の高い40代では35.5％である．慢性閉塞性肺疾患(chronic obstructive pulmonary disease：COPD)は，喫煙を主因とする中高年に発症する生活習慣病であり，喫煙者の15〜20％がCOPDを発症するとされ¹⁾，日本では40歳以上の人口の8.6％，約530万人がCOPDであると推定されている．COPD患者の肺組織像は主に肺胞隔壁の消失を伴う肺気腫である．COPDは骨粗鬆症の危険因子であり，COPD患者では骨粗鬆症の有病率や椎体骨折の発生率が高い^2-4)．肺気腫病変の占拠率は，胸椎の骨密度(bone mineral density：BMD)と負の相関があり⁵⁾，COPD重症度もまた各部位のBMDと関連がある⁶⁾．一方，COPDと骨折に関する疫学調査では，COPD患者におけるBMDに依存しない骨折リスクの上昇が指摘されており，骨質の劣化も示唆されている．モデル動物やヒトの骨生検での検証は遅れており，本質的な病態については解明されておらず，「生活習慣病骨折リスクに関する診療ガイド2019年版」では，基礎研究による機序解明が必要であると言及されている⁷⁾．本稿では，COPDが骨に及ぼす影響について，当教室で得られた知見も含め文献的に考察する．

参考文献

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