title: Psoas Muscle Cross-sectional Area as a Measure of Whole-body Lean Muscle Mass in Maintenance Hemodialysis Patients.
abstract: We investigate whether psoas or paraspinous muscle area measured on a single L4-L5 image is a useful measure of whole lean body mass (LBM) compared to dedicated midthigh magnetic resonance imaging (MRI).
  
  
  
  Observational study.
  
  
  
  Outpatient dialysis units and a research clinic.
  
  
  
  One hundred five adult participants on maintenance hemodialysis. No control group was used.
  
  
  
  Psoas muscle area, paraspinous muscle area, and midthigh muscle area (MTMA) were measured by magnetic resonance imaging.
  
  
  
  LBM was measured by dual-energy absorptiometry scan.
  
  
  
  In separate multivariable linear regression models, psoas, paraspinous, and MTMA were associated with increase in LBM. In separate multivariate logistic regression models, C statistics for diagnosis of sarcopenia (defined as <25th percentile of LBM) were 0.69 for paraspinous muscle area, 0.81 for psoas muscle area, and 0.89 for MTMA. With sarcopenia defined as <10th percentile of LBM, the corresponding C statistics were 0.71, 0.92, and 0.94.
  
  
  
  We conclude that psoas muscle area provides a good measure of whole-body muscle mass, better than paraspinous muscle area but slightly inferior to midthigh measurement. Hence, in body composition studies a single axial MR image at the L4-L5 level can be used to provide information on both fat and muscle and may eliminate the need for time-consuming measurement of muscle area in the thigh.
authors.affiliation: Department of Radiology, University of Utah School of Medicine, Salt Lake City, Utah. Electronic address: glen.morrell@hsc.utah.edu.
authors.forename: Glen R
authors.initials: GR
authors.lastname: Morrell
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Talat A
authors.initials: TA
authors.lastname: Ikizler
authors.affiliation: Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah.
authors.forename: Xiaorui
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Radiology, University of Utah School of Medicine, Salt Lake City, Utah.
authors.forename: Marta E
authors.initials: ME
authors.lastname: Heilbrun
authors.affiliation: Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah.
authors.forename: Guo
authors.initials: G
authors.lastname: Wei
authors.affiliation: Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah.
authors.forename: Robert
authors.initials: R
authors.lastname: Boucher
authors.affiliation: Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah; Veterans Affairs Salt Lake City Healthcare System, Salt Lake City, Utah.
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Beddhu
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D001823:Body Composition; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000628:therapy; D004032:Diet; D004044:Dietary Proteins / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015596:Nutrition Assessment; D011446:Prospective Studies; D016658:Psoas Muscles / Q000033:anatomy & histology*; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000628:therapy; D012709:Serum Albumin / Q000378:metabolism
chemical_list: D004044:Dietary Proteins; D012709:Serum Albumin