Relationship between body mass index (BMI) and decline in FVC in patients with IPF*

Introduction: Lower BMI may be associated with worse prognosis in patients with IPF.

Aim: To assess the association between BMI at baseline and decline in FVC in patients with IPF in the INPULSIS trials.

Methods: In post-hoc analyses, we assessed the rate of decline in FVC (mL/yr) over 52 weeks in subgroups of patients by BMI below and above the median of the trial population at baseline (27 kg/m²) using random coefficient regression.

Results: At baseline, mean FVC was similar between patients with BMI < 27 kg/m² (n = 486; mean BMI: 24.1) and ≥ 27 kg/m² (n = 575; mean BMI: 31.1) (2696 and 2739 mL, respectively). Compared with patients with BMI ≥ 27 kg/m², those with BMI < 27 kg/m² had lower mean DLco (45.8% vs. 48.5% predicted), and greater proportions were of Asian race (51% vs. 13%), had never smoked (31% vs. 26%) and had emphysema (44% vs. 35%). In the placebo group, the mean [SE] rate of decline in FVC over 52 weeks was greater in patients with BMI < vs. ≥ 27 kg/m² (− 266.24 [18.68] vs. − 183.06 [19.11] mL/yr). In the nintedanib group, the mean [SE] rate of decline in FVC was similar in patients with BMI < vs. ≥ 27 kg/m² (− 108.48 [16.24] vs. − 117.69 [14.82] mL/yr, respectively).

Conclusion: In the INPULSIS trials, patients with BMI below the median at baseline showed faster disease progression when treated with placebo, and a more pronounced treatment effect of nintedanib, compared to patients with BMI above the median at baseline.

* presented at ERS 2019, ^‡ presenting on behalf of the authors

Fig. 1 Rate of decline in FVC (mL/yr) over 52 weeks in the INPULSIS trials by BMI below and above the median of the trial population at baseline.