Short- and Long-Term Survival in Patients with Idiopathic Pulmonary Fibrosis and Muscle Loss

Loss of muscle mass and sarcopenia are associated with poor prognosis in chronic respiratory illnesses and are currently emerging as coexisting conditions that deserve attention in patients with idiopathic pulmonary fibrosis (IPF). However, the exact impact of muscle changes in this deadly disease is not entirely understood. Our study aimed to investigate the role of muscle loss/myosteatosis assessed by computed tomography in the short- and long-term survival of patients with IPF treated with antifibrotics.

Ninety-six patients with IPF (16 females, 80 males) were retrospectively enrolled between March 2014 and December 2022. Demographic, functional, and radiological data were collected at diagnosis. Area and density of the paravertebral muscle at the level of the 12th thoracic vertebra were collected, and myosteatosis was defined as Hounsfield Unit (Hu) value <30; moreover, using the same segmentation, 54 radiomic variables were extracted.

Forty-four out of 96 patients (46%) had myosteatosis. Patients with myosteatosis were older (74.6 vs. 67.4 years; p < 0.001) with lower GERD comorbidities (25% vs. 54%; p = 0.006) compared with patients with preserved muscle density. Patients with myosteatosis had lower 2-year survival (p = 0.03), but no significant differences occurred for the overall survival. In the multivariable Cox regression analysis, myosteatosis was an independent predictor of 2-year mortality [HR 6.13, 95% CI (1.62-23.12); p = 0.007].

Myosteatosis is already present in half of the IPF population at diagnosis and impacts short-term survival after 2 years. Our findings highlight the importance of a fully comprehensive assessment of IPF patients to address early nutritional intervention and/or rehabilitation programs.