title: Facial fat volume in HIV-infected patients with lipoatrophy.
abstract: BACKGROUND
  The volume and anatomical distribution of facial fat depletion in HIV related lipoatrophy have not been properly quantified. We aimed to determine the extent and distribution of facial fat loss in HIV-infected patients with lipoatrophy and whether this differs from wasting.
  
  
  METHODS
  We studied HIV-infected patients with clinically defined moderate to severe lipoatrophy without wasting (n = 15), clinically defined wasting (> 10% weight loss and recent opportunistic infection) with no previous reported lipodystrophy (n = 15), and controls without lipodystrophy or wasting (n = 15). Facial MRI scans were performed, and areas of fat were manually traced bilaterally in all individual image slices and summed to calculate volume in anatomically defined regions of interest.
  
  
  RESULTS
  Patients with lipoatrophy had lower fat volumes in the temporal region (8.9 +/- 9.4 vs 20.5 +/- 7.2 ml; P < 0.001), cheek region (25.6 +/- 24.9 vs 55.5 +/- 15.0 ml; P < 0.001), periorbital region (1.9 +/- 1.0 vs 2.7 +/- 1.0 ml; P = 0.09) and buccal fat pad (13.4 +/- 9.4 vs 21.8 +/- 9.8 ml; P = 0.030) compared with controls. Patients with wasting had temporal, cheek, periorbital and buccal fat pad volumes (10.4 +/- 6.7 ml, 34.0 +/- 14.8 ml, 1.4 +/- 1.1 ml and 13.1 +/- 4.6 ml respectively) that were lower than controls (all P < 0.01) but similar to lipoatrophy patients (all P > 0.5).
  
  
  CONCLUSIONS
  Facial fat depletion in lipoatrophy is substantial (approximately 50% volume loss) and involves superficial and deep fat (buccal fat pad). The distribution and volume of fat change is similar to that seen in wasting. Given the extent of the changes, complete surgical correction is unlikely to be possible and hence emphasis should be placed on prevention of lipoatrophy [corrected]
authors.affiliation: Infectious Disease Research Centre, Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.
authors.forename: Yong
authors.initials: Y
authors.lastname: Yang
authors.forename: Yih-Yian
authors.initials: YY
authors.lastname: Sitoh
authors.forename: Naing
authors.initials: N
authors.lastname: Oo Tha
authors.forename: Nicholas I
authors.initials: NI
authors.lastname: Paton
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D001837:Body Weights and Measures; D005145:Face / Q000473:pathology*; D039682:HIV-Associated Lipodystrophy Syndrome / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged