Chest computed tomography-derived low fat-free mass index and mortality in COPD

Merry-Lynn N McDonald; Alejandro A Diaz; Erica Rutten; Sharon M Lutz; Rola Harmouche; Raul San Jose Estepar; Greg Kinney; John E Hokanson; Barbara A Gower; Emiel F M Wouters; Stephen I Rennard; Craig P Hersh; Richard Casaburi; Mark T Dransfield; Edwin K Silverman; George R Washko

doi:10.1183/13993003.01134-2017

Chest computed tomography-derived low fat-free mass index and mortality in COPD

Eur Respir J. 2017 Dec 14;50(6):1701134. doi: 10.1183/13993003.01134-2017. Print 2017 Dec.

Authors

Merry-Lynn N McDonald^{1

2

3}, Alejandro A Diaz^{4

3}, Erica Rutten⁵, Sharon M Lutz⁶, Rola Harmouche⁴, Raul San Jose Estepar⁷, Greg Kinney⁸, John E Hokanson⁸, Barbara A Gower⁹, Emiel F M Wouters⁵, Stephen I Rennard¹⁰, Craig P Hersh^{4

11}, Richard Casaburi¹², Mark T Dransfield¹³, Edwin K Silverman^{4

11}, George R Washko⁴

Affiliations

¹ Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, USA mmcdonald@uab.edu.
² Dept of Genetics, University of Alabama at Birmingham, Birmingham, AL, USA.
³ Both authors contributed equally.
⁴ Division of Pulmonary and Critical Care Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA, USA.
⁵ Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands.
⁶ Dept of Biostatistics, University of Colorado at Denver, Denver, CO, USA.
⁷ Dept of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, MA, USA.
⁸ Dept of Epidemiology, University of Colorado, Denver, Aurora, CO, USA.
⁹ Division of Physiology and Metabolism, Dept of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA.
¹⁰ Dept of Medicine, Nebraska Medical Center, Omaha, Nebraska, USA.
¹¹ Channing Division of Network Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA, USA.
¹² Rehabilitation Clinical Trials Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.
¹³ Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.

Abstract

Low fat-free mass index (FFMI) is an independent risk factor for mortality in chronic obstructive pulmonary disease (COPD) not typically measured during routine care. In the present study, we aimed to derive fat-free mass from the pectoralis muscle area (FFM_PMA) and assess whether low FFMI_PMA is associated with all-cause mortality in COPD cases. We used data from two independent COPD cohorts, ECLIPSE and COPDGene.Two equal sized groups of COPD cases (n=759) from the ECLIPSE study were used to derive and validate an equation to calculate the FFM_PMA measured using bioelectrical impedance from PMA. We then applied the equation in COPD cases (n=3121) from the COPDGene cohort, and assessed survival. Low FFMI_PMA was defined, using the Schols classification (FFMI <16 in men, FFMI <15 in women) and the fifth percentile normative values of FFMI from the UK Biobank.The final regression model included PMA, weight, sex and height, and had an adjusted R² of 0.92 with fat-free mass (FFM) as the outcome. In the test group, the correlation between FFM_PMA and FFM remained high (Pearson correlation=0.97). In COPDGene, COPD cases with a low FFMI_PMA had an increased risk of death (HR 1.6, p<0.001).We demonstrated COPD cases with a low FFMI_PMA have an increased risk of death.

Publication types

Multicenter Study

MeSH terms

Adipose Tissue / anatomy & histology*
Adipose Tissue / diagnostic imaging
Aged
Body Composition
Body Mass Index*
Cohort Studies
Electric Impedance
Female
Humans
Internationality
Male
Middle Aged
Pulmonary Disease, Chronic Obstructive / diagnostic imaging*
Pulmonary Disease, Chronic Obstructive / mortality*
Risk Factors
Survival Analysis
Tomography, X-Ray Computed*

Abstract

Publication types

MeSH terms

Grants and funding