Alessia Comes1, Alyson W Wong2, Jolene H Fisher3, Julie Morisset4, Kerri A Johannson5, Erica Farrand6, Charlene D Fell5, Martin Kolb7, Hélène Manganas4, Gerard Cox7, Andrea S Gershon8, Andrew J Halayko9, Nathan Hambly7, Nasreen Khalil10, Mohsen Sadatsafavi11, Shane Shapera3, Teresa To12, Pearce G Wilcox10, Harold R Collard6, Christopher J Ryerson2. 1. Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy; Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada. Electronic address: alessia.comes@gmail.com. 2. Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada; Department of Medicine, University of British Columbia, Vancouver, BC, Canada. 3. Department of Medicine, University of Toronto, Toronto, ON, Canada. 4. Department of Medicine, Université de Montréal, Montreal, QC, Canada. 5. Department of Medicine, University of Calgary, Calgary, AB, Canada. 6. Department of Medicine, University of California San Francisco, CA. 7. Department of Medicine, McMaster University, Hamilton, ON, Canada. 8. Department of Medicine, University of Toronto, Toronto, ON, Canada; Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, ON, Canada. 9. Departments of Internal Medicine and Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB, Canada. 10. Department of Medicine, University of British Columbia, Vancouver, BC, Canada. 11. Respiratory Evaluation Sciences Program, Collaboration for Outcomes Research and Evaluation, Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, BC, Canada. 12. Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, ON, Canada.
Abstract
BACKGROUND: Mortality risk assessment in interstitial lung disease (ILD) is challenging. Our objective was to determine the prognostic significance of BMI and change in weight in the most common fibrotic ILD subtypes. RESEARCH QUESTION: Could BMI and weight loss over time be reliable prognostic indicators in patients with fibrotic ILD? STUDY DESIGN AND METHODS: This observational retrospective multicenter cohort study enrolled patients with fibrotic ILD from the six-center CAnadian REgistry for Pulmonary Fibrosis (CARE-PF, derivation) and the ILD registry at the University of California, San Francisco (UCSF, validation). Patients were subcategorized as underweight (BMI < 18.5), normal weight (BMI 18.5-24.9), overweight (BMI 25-29.9), or obese (BMI > 30). Annual change in weight was calculated for all years of follow-up as the slope of best fit using the least square method based on every available measurement. Separate multivariable analyses evaluated the associations of BMI and change in weight with mortality, adjusting for common prognostic variables. RESULTS: The derivation and validation cohorts included 1,786 and 1,779 patients, respectively. Compared with patients with normal BMI, mortality was highest in patients who were underweight (hazard ratio [HR], 3.19; 95% CI, 1.88-5.43; P < .001) and was lowest in those who were overweight (HR, 0.52; 95% CI, 0.36-0.75; P < .001) or obese (HR, 0.55; 95%CI, 0.37-0.83; P < .001) in the analysis adjusted for the ILD-GAP (gender, age, physiology) Index. Patients who had a weight loss of at least 2 kg within 1 year had increased risk of death in the subsequent year (HR, 1.41; 95% CI, 1.01-1.97; P = .04) after adjustment for the ILD-GAP Index and baseline BMI category, with a plateau in risk for patients with greater weight loss. Consistent results were observed in the validation cohort. INTERPRETATION: Both BMI and weight loss are independently associated with 1-year mortality in fibrotic ILD. BMI and weight loss may be clinically useful prognostic indicators in fibrotic ILD.
BACKGROUND: Mortality risk assessment in interstitial lung disease (ILD) is challenging. Our objective was to determine the prognostic significance of BMI and change in weight in the most common fibrotic ILD subtypes. RESEARCH QUESTION: Could BMI and weight loss over time be reliable prognostic indicators in patients with fibrotic ILD? STUDY DESIGN AND METHODS: This observational retrospective multicenter cohort study enrolled patients with fibrotic ILD from the six-center CAnadian REgistry for Pulmonary Fibrosis (CARE-PF, derivation) and the ILD registry at the University of California, San Francisco (UCSF, validation). Patients were subcategorized as underweight (BMI < 18.5), normal weight (BMI 18.5-24.9), overweight (BMI 25-29.9), or obese (BMI > 30). Annual change in weight was calculated for all years of follow-up as the slope of best fit using the least square method based on every available measurement. Separate multivariable analyses evaluated the associations of BMI and change in weight with mortality, adjusting for common prognostic variables. RESULTS: The derivation and validation cohorts included 1,786 and 1,779 patients, respectively. Compared with patients with normal BMI, mortality was highest in patients who were underweight (hazard ratio [HR], 3.19; 95% CI, 1.88-5.43; P < .001) and was lowest in those who were overweight (HR, 0.52; 95% CI, 0.36-0.75; P < .001) or obese (HR, 0.55; 95%CI, 0.37-0.83; P < .001) in the analysis adjusted for the ILD-GAP (gender, age, physiology) Index. Patients who had a weight loss of at least 2 kg within 1 year had increased risk of death in the subsequent year (HR, 1.41; 95% CI, 1.01-1.97; P = .04) after adjustment for the ILD-GAP Index and baseline BMI category, with a plateau in risk for patients with greater weight loss. Consistent results were observed in the validation cohort. INTERPRETATION: Both BMI and weight loss are independently associated with 1-year mortality in fibrotic ILD. BMI and weight loss may be clinically useful prognostic indicators in fibrotic ILD.