Background: Although patients with idiopathic pulmonary fibrosis (IPF) often receive treatment with antifibrotic drugs (AFDs) and pulmonary rehabilitation (PR) concurrently, there are no reports on the effect of PR on patients with IPF receiving AFDs. Therefore, we investigated the effect of PR on patients with IPF receiving AFDs. Methods: Eighty-seven eligible patients with IPF (61 male; 72.0 ± 8.1 years; GAP severity stage I/II/III: 26/32/12) were recruited for the study. Patients who completed a 3-month outpatient PR program and those who did not participate were classified into four groups according to use of AFDs: PR group (n = 29), PR+AFD group (n = 11), treatment-free observational group (control group; n = 26), and AFD group (n = 21). There was no significant difference in age, sex, or severity among the groups. Patients were evaluated for physical functions such as 6-min walk distance (6MWD) and muscle strength, dyspnea, and health-related quality of life (HRQOL) at baseline and at 3 months. Results: In the PR group, dyspnea and 6MWD showed significant improvement after the 3-month PR program (p < 0.05 and p < 0.01, respectively). HRQOL was significantly worse at 3 months (p < 0.05) in the AFD group, but not in the other groups. The change in 6MWD from baseline to the 3-month time point was significantly higher in the PR+AFD group than in the AFD groups (p < 0.01). Conclusions: It was suggested that AFD treatment reduced exercise tolerance and HRQOL at 3 months; however, the concurrent use of PR may prevent or mitigate these effects.

Background: In idiopathic pulmonary fibrosis (IPF), 6-minute walking distance (6MWD) is an independent factor for mortality. Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare disease with physical features such as emaciation, but the relationship between IPPFE and 6MWD is unclear. In this study, we investigated the factors that cause a decrease in the percent of the predicted value of a 6-minute walk distance (%6MWD), including the disease entities, IPF and IPPFE. Methods: This study included 100 patients (IPF: 75 patients, IPPFE: 25 patients, age: 73.5 ± 7.2 years, sex: 73 males) who visited the rehabilitation department. Patients with a %6MWD ≥ 80% were assigned to the normal group (n = 54), and patients with a %6MWD < 80% were assigned to the decreased group (n = 46). The items showing a significant difference between groups were used as independent variables, after the consideration of multicollinearity, for a logistic analysis where %6MWD < 80% was used as the dependent variable. Results: The 6MWD results show that there was no significant difference between IPF and IPPFE in the absolute value of 6MWD and in the number of people with 6MWD ≥ 250 m, but when 6MWD was compared with %6MWD, the IPPFE group showed a significantly lower value than the IPF group (p = 0.013). Logistic regression analysis showed that only BMI (p = 0.032), GAP index (p = 0.043), and mMRC (p = 0.026) were factors that caused a decrease in %6MWD in 100 patients. Conclusion: The results suggest that leanness, shortness of breath and severity of illness are the most important factors that determine exercise tolerance, regardless of disease entity in IPF and IPPFE.