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

Abstract

IntroductionLower BMI may be associated with worse prognosis in patients with IPF.AimTo assess the association between BMI at baseline and decline in FVC in patients with IPF in the INPULSIS trials.MethodsIn 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.ResultsAt 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).ConclusionIn 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.