Does body mass index influence survival of patients with idiopathic pulmonary fibrosis

Aim: It has been reported that a high body mass index (BMI) is associated with better survival in patients with idiopathic pulmonary fibrosis (IPF). We aimed to find out whether body mass index influences survival of patients with idiopathic pulmonary fibrosis. Methods: We examined the relationship between BMI and survival in our cohort of patients with IPF. These patients were first seen in our clinic between May 2008 and January 2018. All had a diagnosis of IPF based on clinical assessment and high resolution CT scan; one third underwent a surgical lung biopsy. Height and body weight were ascertained at the first consultation. Survival analysis was performed using SPSS version 16. Results: We had data on 367 patients. The median age at first consultation was 66 years (range 39 to 97). There were 272 men and 95 women. At presentation, 6 were underweight (BMI 30). On Kaplan-Meier survival analysis, there was no significant difference in survival between these categories (p=0.75). Conclusion: The differences between the groups did not reach clinical significance. The graph suggests that being underweight is an adverse prognostic factor, but the number of such patients was very small. It also suggests that obesity may be marginally beneficial for the first four years but not thereafter.