title: Quantitative and qualitative differences in subcutaneous adipose tissue stores across lipodystrophy types shown by magnetic resonance imaging.
abstract: BACKGROUND
  Lipodystrophies are characterized by redistributed subcutaneous fat stores. We previously quantified subcutaneous fat by magnetic resonance imaging (MRI) in the legs of two patients with familial partial lipodystrophy subtypes 2 and 3 (FPLD2 and FPLD3, respectively). We now extend the MRI analysis across the whole body of patients with different forms of lipodystrophy.
  
  
  METHODS
  We studied five subcutaneous fat stores (supraclavicular, abdominal, gluteal, thigh and calf) and the abdominal visceral fat stores in 10, 2, 1, 1 and 2 female subjects with, respectively, FPLD2, FPLD3, HIV-related partial lipodystrophy (HIVPL), acquired partial lipodystrophy (APL), congenital generalized lipodystrophy (CGL) and in six normal control subjects.
  
  
  RESULTS
  Compared with normal controls, FPLD2 subjects had significantly increased supraclavicular fat, with decreased abdominal, gluteal, thigh and calf subcutaneous fat. FPLD3 subjects had increased supraclavicular and abdominal subcutaneous fat, with less severe reductions in gluteal, thigh and calf fat compared to FPLD2 subjects. The repartitioning of fat in the HIVPL subject closely resembled that of FPLD3 subjects. APL and CGL subjects had reduced upper body, gluteal and thigh subcutaneous fat; the APL subject had increased, while CGL subjects had decreased subcutaneous calf fat. Visceral fat was markedly increased in FPLD2 and APL subjects.
  
  
  CONCLUSIONS
  Semi-automated MRI-based adipose tissue quantification indicates differences between various lipodystrophy types in these studied clinical cases and is a potentially useful tool for extended quantitative phenomic analysis of genetic metabolic disorders. Further studies with a larger sample size are essential for confirming these preliminary findings.
authors.affiliation: Vascular Biology Research Group, Robarts Research Institute, London, Ontario, N6A 5K8, Canada. salattar@robarts.ca
authors.forename: Salam A
authors.initials: SA
authors.lastname: Al-Attar
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Pollex
authors.forename: John F
authors.initials: JF
authors.lastname: Robinson
authors.forename: Brooke A
authors.initials: BA
authors.lastname: Miskie
authors.forename: Rhonda
authors.initials: R
authors.lastname: Walcarius
authors.forename: Cynthia Harper
authors.initials: CH
authors.lastname: Little
authors.forename: Brian K
authors.initials: BK
authors.lastname: Rutt
authors.forename: Robert A
authors.initials: RA
authors.lastname: Hegele
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008060:Lipodystrophy / Q000145:classification* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity