Real-World Clinical Outcomes Based on Body Mass Index and Annualized Weight Change in Patients with Idiopathic Pulmonary Fibrosis

INTRODUCTION: Identification of clinical characteristics associated with prognosis for idiopathic pulmonary fibrosis (IPF) may help to guide management decisions. This analysis utilized data from the Pulmonary Fibrosis Foundation Patient Registry to examine the relationships between clinical outcomes and both body mass index (BMI) at study enrollment (hereafter referred to as baseline BMI) and annualized percent change in body weight in patients with IPF in a real-world setting. METHODS: The following outcomes over 24 months were stratified by baseline BMI and annualized percent change in body weight: all-cause mortality; annualized change in percent predicted forced vital capacity (%FVC), percent predicted diffusing capacity for carbon monoxide, and 6-min walk distance; all-cause and respiratory-related hospitalizations; and acute exacerbations. RESULTS: Overall, 600 patients with IPF were included (baseline BMI: < 25 kg/m(2), n = 120; 25 to < 30 kg/m(2), n = 242; ≥ 30 kg/m(2), n = 238; annualized percent change in body weight: no loss, n = 95; > 0% to < 5% loss, n = 425; ≥ 5% loss, n = 80). Enrollment demographics and characteristics were generally similar across subgroups. There was no association between mortality and BMI. All-cause mortality was lower among patients who experienced no annualized weight loss versus those with ≥ 5% (OR [95% CI] 3.28 [1.15, 10.95]) or > 0 to < 5% weight loss (OR [95% CI] 2.83 [1.14, 8.62]) over 24 months. Patients with baseline BMI < 25 kg/m(2) had a significantly greater estimated annualized decline in %FVC versus patients with baseline BMI ≥ 30 kg/m(2) (difference [95% CI] 1.47 [0.01, 2.93]). No relationship was observed between %FVC and weight loss. Other clinical outcomes were generally similar across subgroups. CONCLUSIONS: Some clinical outcomes may be worse in patients with IPF who have a low BMI (< 25 kg/m(2)) or who experience weight loss over 24 months, but the causation for these relationships is unknown. These results may help to inform management decisions for patients with IPF. CLINICALTRIALS.GOV IDENTIFIER: NCT02758808. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12325-022-02382-0.