Cause of mortality and sarcopenia in patients with idiopathic pulmonary fibrosis receivingantifibrotictherapy

Background and objective Recent research has highlighted the fundamental role of sarcopenia, characterized by loss of skeletal muscle mass and strength, with a risk of poor outcomes. AFT preserves lung function by preventing the annual decline in FVC and is associated with improved outcomes in patients with IPF. However, altered cause of death and prognostic implications of sarcopenia in patients with IPF receiving AFT remain unknown. Methods This study comprised two cohorts of patients with IPF receiving AFT, historical cohort of IPF patients without AFT and controls. The cause of mortality was compared with a historical cohort. Sarcopenia was assessed by measuring the ESM(CSA)and ESM(MA)via CT. Results Patients with IPF had smaller ESM(CSA)and lower ESM(MA)but similar BMI than controls, suggesting patients with IPF had skeletal muscle loss without any obvious body weight loss. The most common cause of mortality in patients receiving AFT was chronic respiratory failure, accounting for approximately 60%, and decreased proportions of LC were found. Subsequently, low ESM(CSA)was an independent prognostic factor associated with worse survival rates. Furthermore, combined assessment of ESMCSA, %FVC predicted and BMI values provided clear prognostic distinction. Conclusion Patients with IPF receiving AFT showed skeletal muscle loss without obvious weight loss. These patients mostly died by chronic respiratory failure, and skeletal muscle wasting has prognostic significance, suggesting that preventing sarcopenia as well as preserving lung function are important for managing these patients.