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

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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 (FFMPMA) and assess whether low FFMIPMA 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 FFMPMA measured using bioelectrical impedance from PMA. We then applied the equation in COPD cases (n = 3121) from the COPDGene cohort, and assessed survival. Low FFMIPMA 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 R-2 of 0.92 with fat-free mass (FFM) as the outcome. In the test group, the correlation between FFMPMA and FFM remained high (Pearson correlation = 0.97). In COPDGene, COPD cases with a low FFMIPMA had an increased risk of death (HR 1.6, p <0.001).

We demonstrated COPD cases with a low FFMIPMA have an increased risk of death.

Original languageEnglish
Article number1701134
Number of pages10
JournalEuropean Respiratory Journal
Volume50
Issue number6
DOIs
Publication statusPublished - 1 Dec 2017

Keywords

  • OBSTRUCTIVE PULMONARY-DISEASE
  • RESPIRATORY SOCIETY STATEMENT
  • PECTORALIS-MUSCLE AREA
  • X-RAY ABSORPTIOMETRY
  • BODY-COMPOSITION
  • LUNG-CANCER
  • NUTRITIONAL ASSESSMENT
  • CLINICAL-PRACTICE
  • SKELETAL-MUSCLE
  • TISSUE

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