@article {McDonald1701134, author = {Merry-Lynn N. McDonald and Alejandro A. Diaz and Erica Rutten and Sharon~M. Lutz and Rola Harmouche and Raul San Jose Estepar and Greg Kinney and John E. Hokanson and Barbara A. Gower and Emiel F.M. Wouters and Stephen I. Rennard and Craig P. Hersh and Richard Casaburi and Mark T. Dransfield and Edwin K. Silverman and George R. Washko}, title = {Chest computed tomography-derived low~fat-free mass index and mortality in~COPD}, volume = {50}, number = {6}, elocation-id = {1701134}, year = {2017}, doi = {10.1183/13993003.01134-2017}, publisher = {European Respiratory Society}, 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 R2 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.Low fat-free mass index (FFMI) derived from chest CT is associated with reduced survival among COPD cases http://ow.ly/KNaU30gsFZM}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/50/6/1701134}, eprint = {https://erj.ersjournals.com/content/50/6/1701134.full.pdf}, journal = {European Respiratory Journal} }