Short communicationAssociation of BMI with pulmonary function, functional capacity, symptoms, and quality of life in ILD
Introduction
Fibrotic interstitial lung diseases (ILDs) are associated with significant morbidity, most notably dyspnea, reduced exercise tolerance, and poor quality of life. Higher body mass index (BMI) is associated with increased mortality in the general population [1], but conversely associated with lower all-cause mortality in both chronic obstructive pulmonary disease (COPD) and fibrotic ILD [[2], [3], [4], [5]]; however, the impact of BMI on morbidity in ILD is unknown. In this study, we tested the association of baseline BMI with pulmonary function, functional capacity, and patient-reported outcomes (dyspnea and quality of life) in fibrotic ILD, hypothesizing that increasing BMI would be associated with greater morbidity.
Section snippets
Methods
This retrospective study included patients with fibrotic ILD from the Canadian Registry for Pulmonary Fibrosis who had at least one measurement of height and body mass [6]. Research ethics board approval was obtained at all participating sites (coordinating site: University of British Columbia H19-01989).
BMI was calculated based on the first available measurements of height and body mass from pulmonary function testing (i.e., baseline) and subcategorized as underweight (BMI<18.5 kg/m2), normal
Results
A total of 3169 patients (50% male) were included, with mean age 62 ± 13 years, BMI 28.8 ± 5.8 kg/m2 (1% underweight, 25% normal weight, 37% overweight, 23% obese I, 9% obese II, and 4% obese III), FVC 79 ± 20 %-predicted, and DLCO 62 ± 20 %-predicted.
The unadjusted association of BMI category with each outcome variable is shown in Fig. 1. The lowest and highest BMI groups had the lowest 6MWD and EQ5D VAS, while UCSD SOBQ scores were highest in the obese groups. Normal weight was typically
Discussion
Obesity is increasing in prevalence and considered a health epidemic in many countries [7]. Beyond the previously demonstrated association of BMI with mortality in patients with fibrotic ILD [5], we show that: 1) overweight and particularly obese BMI categories are associated with lower pulmonary function, lower functional capacity, worse dyspnea, and poorer quality of life compared to normal weight; and 2) the underweight BMI category is also associated with worse functional capacity compared
Funding
The CAnadian REgistry for Pulmonary Fibrosis (CARE-PF) is funded by Boehringer Ingelheim (Grant #: 20R23666).
Role of the sponsors
The funders had no role in the study design, data collection and analysis, or preparation of the manuscript.
Other contributions
The authors thank the patients who agreed to participate in the CARE-PF registry.
Summary of conflicts of interest statements
None of the authors report competing interests.
Financial/non-financial disclosures
DA, NK, MK, HM, and CJR report grants from Boehringer Ingelheim. DA, JHF, KAJ, NK, MK, VM, and CJR report personal fees from Boehringer Ingelheim. DA, KAJ, MK, VM, and CJR report personal fees from Hoffman La Roche. JHF, KAJ, and CJR report personal fees from Astra Zeneca. MK, VM, and CJR report grants from Hoffman La Roche. MK and CJR report personal fees from Cipla Ltd. JHF also reports grants from the Canadian Pulmonary Fibrosis Foundation, where she served on the medical advisory board, and
CRediT authorship contribution statement
Michele R. Schaeffer: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Software, Visualization, Writing – original draft, Writing – review & editing. Divjot S. Kumar: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Writing – original draft, Writing – review & editing. Deborah Assayag: Investigation, Project administration, Writing – review & editing. Jolene H. Fisher: Investigation, Project administration, Writing – review & editing.
References (10)
- et al.
Body mass index and mortality in patients with idiopathic pulmonary fibrosis
Chest
(2007) - et al.
The effects of body mass index on lung volumes
Chest
(2006) - et al.
The impact of bariatric surgery on pulmonary function: a meta-analysis
Surg. Obes. Relat. Dis.
(2018) - et al.
The incidence of co-morbidities related to obesity and overweight: a systematic review and meta-analysis
BMC Publ. Health
(2009) - et al.
Body mass index and mortality in chronic obstructive pulmonary disease: a dose-response meta-analysis
Medicine (Baltim.)
(2016)
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