title: Tongue fat and its relationship to obstructive sleep apnea.
abstract: OBJECTIVE
  The objective of this study was to determine whether tongue fat is increased in obese sleep apneics compared to obese subjects without sleep apnea. We hypothesized that excess fat is deposited in the tongue in obese patients with sleep apnea.
  
  
  METHODS
  Case-control design.
  
  
  METHODS
  Academic medical center.
  
  
  METHODS
  We examined tongue fat in 31 obese controls (apnea-hypopnea index, 4.1 ± 2.7 events/h) and 90 obese apneics (apnea-hypopnea index, 43.2 ± 27.3 events/h). Analyses were repeated in a subsample of 18 gender-, race-, age-, and BMI-matched case-control pairs.
  
  
  METHODS
  All subjects underwent a MRI with three-point Dixon magnetic resonance imaging. We used sophisticated volumetric reconstruction algorithms to study the size and distribution of upper airway fat deposits in the tongue and masseter muscles within apneics and obese controls.
  
  
  RESULTS
  The data supported our a priori hypotheses that after adjustment for age, BMI, gender, and race, the tongue in apneics was significantly larger (P = 0.001) and had an increased amount of fat (P = 0.002) compared to controls. Similar results were seen in our matched sample. Our data also demonstrate that within the apneic and normal tongue, there are regional differences in fat distribution, with larger fat deposits at the base of the tongue.
  
  
  CONCLUSIONS
  There is increased tongue volume and deposition of fat at the base of tongue in apneics compared to controls. Increased tongue fat may begin to explain the relationship between obesity and obstructive sleep apnea.
authors.affiliation: Center for Sleep & Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Kim
authors.affiliation: Center for Sleep & Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA.
authors.forename: Brendan T
authors.initials: BT
authors.lastname: Keenan
authors.affiliation: Center for Sleep & Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Jackson
authors.affiliation: Center for Sleep & Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA.
authors.forename: Eugenia L
authors.initials: EL
authors.lastname: Chan
authors.affiliation: Center for Sleep & Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA.
authors.forename: Bethany
authors.initials: B
authors.lastname: Staley
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, PA.
authors.forename: Harish
authors.initials: H
authors.lastname: Poptani
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, PA.
authors.forename: Drew A
authors.initials: DA
authors.lastname: Torigian
authors.affiliation: Center for Sleep & Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA and Division of Sleep Medicine, Department of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Allan I
authors.initials: AI
authors.lastname: Pack
authors.affiliation: Center for Sleep & Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA and Division of Sleep Medicine, Department of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schwab
mesh_terms: D050154:Adiposity; D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008406:Masseter Muscle / Q000033:anatomy & histology / Q000503:physiopathology; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology; D044469:Racial Groups; D012137:Respiratory System / Q000033:anatomy & histology / Q000503:physiopathology; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*; D014059:Tongue / Q000033:anatomy & histology* / Q000503:physiopathology
keywords: obstructive sleep apnea; tongue fat