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

Abstract

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.

Administration of Collagen Peptide Prevents the Progression of Pulmonary Fibrosis in Bleomycin-Treated Mice

“…Body weight loss post-BLM treatment was partially recovered during the experimental diet period; however, the final body weights of the mice in both BLM-treated groups (BLM-CS and BLM-CP) were significantly lower than those in Ctrl group (p < 0.01). These results suggest that BLM treatment in C57BL/6J mice resulted in persistent body weight loss, which is widely seen in patients with IPF [39].…”

Association between body fat decrease during the first year after diagnosis and the prognosis of idiopathic pulmonary fibrosis: CT-based body composition analysis

“…To stratify the prognosis of patients with IPF, several prognostic factors, including pulmonary function test (PFT) results, fibrosis extent on CT images, mean pulmonary arterial pressure, aging, and cigarette smoke, have been developed [ 1 , 6 , 13 , 30 , 32 , 33 ]. Although weight loss and low baseline BMI have been identified as poor prognostic factors in IPF patients [ 11 , 14 , 15 , 17 , 18 , 20 – 22 ], the prognostic role of change in body fat remains unclear because of difficulties in measuring body composition. While body composition parameters obtained from bioelectric impedance and dual-energy X-ray absorptiometry have shown correlations with lung function, health-related quality of life, and survival in IPF and other fibrotic interstitial lung diseases, their focus has primarily been on fat-free mass or skeletal muscle, rather than body fat [ 34 – 36 ].…”

“…The results of this study are in line with previous studies assessing the prognostic value of weight loss and its association with FVC decline in IPF patients. Specifically, significant weight loss, defined as ≥ 5% of baseline weight, was an independent predictor of mortality [ 11 , 12 , 15 , 18 – 22 , 39 ], acute exacerbation [ 15 ], and hospitalization [ 16 ] in IPF patients. Regarding PFT results, a greater FVC decline in IPF patients was reported to be associated with significant weight loss and low baseline BMI [ 11 , 14 , 15 , 20 , 21 ].…”

“…An increase in caloric requirements due to the increased work of breathing and decreased appetite by side-effects of antifibrotics, persistent cough, or psychosocial issues such as depression are presumed to cause unintended weight loss in IPF patients [ 13 ]. Indeed, studies have reported that low baseline body mass index (BMI) [ 14 – 17 ] or a decrease in body weight and BMI during the disease course [ 11 , 12 , 14 , 15 , 18 – 22 ] can adversely affect the prognosis of patients with IPF. However, these somatotype indicators only reflect the total weight (i.e., a sum of body fat, muscle, bone, and organs), not the body composition.…”