Reduced CT-derived erector spinae muscle area: a poor prognostic factor for short- and long-term outcomes in idiopathic pulmonary fibrosis patients

•CT-based erector spinae muscle area (ESMA) analysis aids IPF management. •ESMA measurements predict short and long-term survival in IPF. •A reduction in ESMA is related to poor prognosis in IPF patients. AIM To assess the relationship between idiopathic pulmonary fibrosis (IPF) prognosis, baseline skeletal muscle mass, and attenuation on computed tomography (CT) and clinical parameters. MATERIAL AND METHODS This retrospective cohort study enrolled 195 patients. The mean follow-up duration was 42.52 months. Erector spinae muscle area (ESMA), pectoralis muscle area (PMA), and the attenuation of the erector spinae muscle at the level of T12 vertebrae were measured. Muscle indexes were obtained by adjusting the measured muscle areas to the patients' heights. The relationship between baseline CT-derived muscle metrics and clinical parameters including short- and long-term mortality were evaluated. RESULTS There was a moderate correlation between ESMA and PMA and pectoralis muscle index (PMI; r=0.536, p<0001 and r=0.403, p<0.001 respectively). ESMA correlated significantly with forced expiratory volume in 1 second (FEV1; hazard ratio [HR] = 0.488 p<0.001) and forced vital capacity (FVC; HR=0.501, p<0.001). Compared with PMA, ESMA was more strongly associated with 1- and 2-year mortality in patients with IPF (HR=0.957, p=0.022). The survival rate in male patients with sarcopenia was significantly worse (p=0.040). CONCLUSION ESMA measurements obtained from CT correlated with clinical parameters in IPF patients and were also predictors of short- and long-term survival. To assess the relationship between idiopathic pulmonary fibrosis (IPF) prognosis, baseline skeletal muscle mass, and attenuation on computed tomography (CT) and clinical parameters. This retrospective cohort study enrolled 195 patients. The mean follow-up duration was 42.52 months. Erector spinae muscle area (ESMA), pectoralis muscle area (PMA), and the attenuation of the erector spinae muscle at the level of T12 vertebrae were measured. Muscle indexes were obtained by adjusting the measured muscle areas to the patients' heights. The relationship between baseline CT-derived muscle metrics and clinical parameters including short- and long-term mortality were evaluated. There was a moderate correlation between ESMA and PMA and pectoralis muscle index (PMI; r=0.536, p<0001 and r=0.403, p<0.001 respectively). ESMA correlated significantly with forced expiratory volume in 1 second (FEV1; hazard ratio [HR] = 0.488 p<0.001) and forced vital capacity (FVC; HR=0.501, p<0.001). Compared with PMA, ESMA was more strongly associated with 1- and 2-year mortality in patients with IPF (HR=0.957, p=0.022). The survival rate in male patients with sarcopenia was significantly worse (p=0.040). ESMA measurements obtained from CT correlated with clinical parameters in IPF patients and were also predictors of short- and long-term survival.