Nutritional assessments as predictors of prognosis after long-term oxygen therapy in patients with idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF), a chronic and progressive interstitial lung disease, frequently leads to chronic respiratory failure, necessitating long-term oxygen therapy (LTOT). Although the prognosis of patients with IPF receiving LTOT is generally poor, limited data are available on clinical factors associated with post-LTOT survival. This study aimed to investigate whether baseline nutritional status at the time of initiation of LTOT is associated with survival outcomes in patients with IPF.

Methods

We retrospectively reviewed 55 patients with IPF and chronic respiratory failure who initiated LTOT. Patients were stratified into two groups based on 1-year survival following LTOT initiation: long-term survivors (≥1 year) and short-term survivors (<1 year). Nutritional status at baseline was assessed using the Geriatric Nutritional Risk Index (GNRI), Prognostic Nutritional Index (PNI), body mass index (BMI), and fat-free mass index (FFMI).

Results

Significant differences were identified between the two groups in BMI, GNRI scores, and the proportion of patients receiving antifibrotic agents. In multivariable analyses adjusted for age, sex and the use of antifibrotic agents, both a GNRI score <92 and a low FFMI were independently associated with increased mortality risk (p = 0.033 and p = 0.007, respectively). Kaplan–Meier analysis demonstrated significantly poorer 1-year survival in patients with GNRI <92 and low FFMI (p = 0.037 and p = 0.006, respectively).

Conclusion

GNRI and FFMI independently predicted 1-year survival in IPF patients on LTOT. These findings underscore the importance of nutritional evaluation at LTOT initiation and suggest that low GNRI and FFMI warrant closer monitoring and targeted nutritional interventions.