サルコペニアの診断法～高齢者の転倒・骨折予防を目的として～

Fall Risk and Fracture. Diagnosing sarcopenia and sarcopenic leg to prevent fall and fracture：its difficulty and pit falls.

　サルコペニアの診断は，身体機能の評価と骨格筋量測定を組み合わせて行う。身体機能は歩行速度と握力を測定する。筋量は，二重Ｘ線吸光度測定（dual energy X-ray absorptiometry：DXA）法や生体電気インピーダンス（bioelectrical impedance analysis：BIA）法で測定し，skeletal muscle mass index［SMI（kg/m2）＝（両上肢筋量＋両下肢筋量）/身長2］で評価する方法が主流である。サルコペニア，特に下肢の筋量・筋力低下が，身体不安定性と易転倒性に関連し骨折の危険因子となる。サルコペニアの予防と治療が高齢者の転倒・骨折予防の鍵となる。

　Diagnosis of sarcopenia is based on the combination of physical-performance assessment and muscle-mass measurement. Physical performance was estimated by gait speed and grip strength. Common measuring procedures for skeletal muscle mass were dual energy X-ray absorptiometry（DXA）and bioelectrical impedance analysis（BIA）．Skeletal muscle mass index（SMI）was calculated from following formula；［SMI（kg/m2）＝（arm lean mass＋leg lean mass）/height2］．Sarcopenia and sarcopenic leg are associated with poor body balance, falls, and subsequent fracture. Treatment of sarcopenia may result in successful prevention of fall and fracture for frail elderly.