重症患者における筋萎縮と尿中タイチン濃度測定の意義

Skeletal muscle atrophy is a serious problem in critically ill patients. After intensive care unit （ICU）admission, muscle atrophy starts within ３ days and progressively worsens thereafter. We have previously reported that upper and lower limb muscle mass of critically ill patients decreased by １３%‐２１% within ７ days of admission. Muscle atrophy in the ICU is associated with long-term functional impairment and weakness in ICU survivors. Although monitoring of muscle mass is important, there have been no reliable biomarkers associated with muscle atrophy in critically ill patients. In this study, we have focused on urinary titin, which is the biggest giant sarcomere protein and functions as a spring for muscle extension and viscoelasticity. We have clarified that urinary titin level reflected muscle breakdown correlated with limb muscle atrophy in non-surgical critically ill patients. The cumulative urinary titin level associated with the incidence of ICU-AW and ICU mortality. Our study indicates urinary titin can be the noble biomarker to evaluate the catabolism and muscle atrophy in critically ill patients.