title: Quantitative analysis of skeletal muscle mass in patients with rheumatic diseases under glucocorticoid therapy--comparison among bioelectrical impedance analysis, computed tomography, and magnetic resonance imaging.
abstract: OBJECTIVE
  To determine the availability of bioelectrical impedance analysis (BIA), computed tomography (CT), and magnetic resonance imaging (MRI) for measurement of skeletal muscle mass in patients with rheumatic diseases and quantitatively assess skeletal muscle loss after glucocorticoid (GC) treatment.
  
  
  METHODS
  The data from 22 patients with rheumatic diseases were retrospectively obtained. The muscle mass of body segments was measured with a BIA device in terms of skeletal muscle mass index (SMI). Cross-sectional area (CSA) was obtained from CT and MRI scans at the mid-thigh level using the image analysis program. We further assessed the data of three different measurements before and after GC treatment in 7 patients with rheumatic diseases.
  
  
  RESULTS
  SMI of whole body was significantly correlated with estimated muscle volume and mid-thigh muscle CSA with CT and MRI (p < 0.01). Significant correlations between SMI and mid-thigh muscle CSA of each leg were also found (p < 0.01). All the three measurements were negatively correlated with GC dosage (p < 0.01). Significant decline in mid-thigh muscle CSA with CT and MRI was found after GC treatment in 7 patients (p < 0.02). Those patients showed significant decline in SMI of whole body after GC treatment, but not in SMI of each leg. On the other hand, significant correlations between mid-thigh muscle CSA with CT and MRI were found before and after GC treatment (p < 0.01).
  
  
  CONCLUSIONS
  GC-related skeletal muscle loss could be quantitatively assessed with BIA, CT, or MRI in patients with rheumatic diseases, and CT and MRI appeared to be more accurate than BIA.
authors.affiliation: Department of Rheumatology and Allergy, IMSUT Hospital, The Institute of Medical Science, The University of Tokyo , Minato-ku, Tokyo , Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Hosono
authors.forename: Noritada
authors.initials: N
authors.lastname: Yoshikawa
authors.forename: Noriaki
authors.initials: N
authors.lastname: Shimizu
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kiryu
authors.forename: Masaaki
authors.initials: M
authors.lastname: Uehara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Ryo
authors.initials: R
authors.lastname: Matsumiya
authors.forename: Akiko
authors.initials: A
authors.lastname: Kuribara
authors.forename: Takako
authors.initials: T
authors.lastname: Maruyama
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D000328:Adult; D000368:Aged; D001823:Body Composition / Q000502:physiology*; D017097:Electric Impedance; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D009929:Organ Size; D011859:Radiography; D012216:Rheumatic Diseases / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology* / Q000503:physiopathology; D013848:Thigh / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D016896:Treatment Outcome
chemical_list: D005938:Glucocorticoids
keywords: Bioelectrical impedance analysis; Computed tomography; Glucocorticoid; Magnetic resonance imaging; Muscle atrophy