Early decrease in erector spinae muscle area and future risk of mortality in idiopathic pulmonary fibrosis

<jats:title>Abstract</jats:title><jats:p>Computed tomography (CT) assessment of the cross-sectional area of the erector spinae muscles (ESM<jats:sub>CSA</jats:sub>) can be used to evaluate sarcopenia and cachexia in patients with lung diseases. This study aimed to confirm whether serial changes in ESM<jats:sub>CSA</jats:sub> are associated with survival in patients with idiopathic pulmonary fibrosis <jats:bold>(</jats:bold>IPF). Data from consecutive patients with IPF who were referred to a single centre were retrospectively reviewed. We measured the ESM<jats:sub>CSA</jats:sub> at the level of the 12th thoracic vertebra on CT images at referral and 6 months later (n = 119). The follow-up time was from 817–1633 days (median, 1335 days<jats:underline>)</jats:underline> and 59 patients (49.6%) died. A univariate Cox regression analysis showed that the decline in % predicted forced vital capacity (FVC) (Hazard ratios [HR] 1.041, 95% confidence interval [CI] 1.013–1.069, P = 0.004), the decline in body mass index (BMI) (HR 1.084, 95% CI 1.037–1.128; P < 0.001) and that in ESM<jats:sub>CSA</jats:sub> (HR 1.057, 95% CI 1.027–1.086; P < 0.001) were prognostic factors. For multivariate analyses, the decline in ESM<jats:sub>CSA</jats:sub> (HR 1.039, 95% CI 1.007–1.071, P = 0.015) was a significant prognostic factor, while those in % FVC and BMI were discarded. Early decrease in ESM<jats:sub>CSA</jats:sub> may be a useful predictor of prognosis in patients with IPF.</jats:p>