title: Pre-transplant wasting (as measured by muscle index) is a novel prognostic indicator in lung transplantation.
abstract: BACKGROUND
  Frailty in non-transplant populations increases morbidity and mortality. Muscle wasting is an important frailty characteristic. Low body mass index is used to measure wasting, but can over- or underestimate muscle mass. Computed tomography (CT) software can directly measure muscle mass. It is unknown if muscle wasting is important in lung transplantation.
  
  
  OBJECTIVE
  The aim of this single-center, retrospective cohort study was to determine whether pre-transplant low muscle mass (as measured by CT using Slice-O-matic software at L2-L3 interspace) was associated with post-transplantation mortality, hospital and intensive care unit length of stay (LOS), duration of mechanical ventilation, or primary graft dysfunction. Lung transplant recipients from 2000 to 2012 with a CT scan less than six months prior to transplant were included. Univariate, multivariate, and Kaplan-Meier analyses were conducted.
  
  
  RESULTS
  Thirty-six patients were included. Those with low muscle index (lower 25th percentile) had a worse survival (hazard ratio = 3.83; 95% confidence interval 1.42-10.3; p = 0.007) and longer hospital LOS by an estimated 7.2 d (p = 0.01) when adjusted for age and sex as compared to those with higher muscle index.
  
  
  CONCLUSIONS
  Low muscle index at lung transplantation is associated with worse survival and increased hospital LOS.
authors.affiliation: Division of Pulmonary Critical Care Medicine, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Diana J
authors.initials: DJ
authors.lastname: Kelm
authors.affiliation: Division of General Internal Medicine, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Sara L
authors.initials: SL
authors.lastname: Bonnes
authors.affiliation: Division of Endocrinology and Metabolic Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Jensen
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Eiken
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Hathcock
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA.|William J. Von Liebig Transplant Center, Mayo Clinic, Rochester, MN, USA.
authors.forename: Walter K
authors.initials: WK
authors.lastname: Kremers
authors.affiliation: Division of Pulmonary Critical Care Medicine, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.|William J. Von Liebig Transplant Center, Mayo Clinic, Rochester, MN, USA.
authors.forename: Cassie C
authors.initials: CC
authors.lastname: Kennedy
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D006085:Graft Survival; D006801:Humans; D008171:Lung Diseases / Q000601:surgery*; D016040:Lung Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009133:Muscular Atrophy / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011183:Postoperative Complications; D055031:Primary Graft Dysfunction / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: body composition; frailty; lung transplantation; mortality; muscle wasting