Clinical impact of weight loss on mortality in patients with idiopathic pulmonary fibrosis: a retrospective cohort study

Patients with idiopathic pulmonary fibrosis (IPF) often experience weight loss during the follow-up period. However, the prevalence and clinical impact of weight loss in these patients still need to be elucidated. This retrospective single-center study reviewed 134 consecutive patients diagnosed with IPF. Weight loss of 5% or more over 1 year was defined as significant weight loss. Clinical data of patients were compared according to the significant weight loss. We analyzed whether the clinical impact of significant weight loss differed regarding the pirfenidone dose. The median follow-up period was 22.1 months. The mean age of patients was 67.3 years, and 92.5% were men. Of the 134 patients, 42 (31.3%) showed significant weight loss. Multivariate cox regression analysis revealed that significant weight loss was independently associated with mortality (hazard ratio [HR]; 2.670; 95% confidence interval [CI] 1.099–6.484; p = 0.030) after adjusting for lung function and other significant risk factors (6-min walk test distance: HR, 0.993; 95% CI 0.987–0.998; p = 0.005). The median survival of patients with significant weight loss (n = 22) was relevantly shorter than that of those without significant weight loss (n = 43) in the reduced dose pirfenidone group (28.2 ± 3.3 vs. 43.3 ± 3.2 months, p = 0.013). Compared with patients without significant weight loss (n = 38), patients with significant weight loss (n = 15) also showed a marginally-significant shorter survival in the full-dose pirfenidone group (28.9 ± 3.1 vs. 39.8 ± 2.6 months, p = 0.085). Significant weight loss is a prognostic factor in patients with IPF regardless of pirfenidone dose. Vigilant monitoring might be necessary to detect weight loss during the clinical course in these patients.