title: Visceral adiposity is closely correlated with neck circumference and represents a significant indicator of insulin resistance in WHO grade III obesity.
abstract: OBJECTIVE
  Although associations between visceral adiposity (intra-abdominal fat mass) and insulin resistance are well established, previous data include few subjects with WHO grade III obesity [body mass index (BMI) > 40 kg/m(2)]. We have investigated the relationship between visceral adiposity and insulin resistance using computed tomography (CT)-quantified fat mass and the homeostasis model assessment for insulin resistance (HOMA-IR) in patients with severe obesity.
  
  
  METHODS
  Eighteen nondiabetic subjects with BMI > 40 kg/m(2) were recruited. BMI, and waist, hip and neck circumferences were measured. Fasting plasma insulin and glucose were measured to calculate HOMA-IR. A single slice CT scan was taken at L4 and visceral and abdominal subcutaneous adipose tissue (VAT and ASAT, respectively) quantified using 'SliceOmatic' image analysis software.
  
  
  RESULTS
  A close correlation was demonstrated between VAT and HOMA-IR (r(2) = 0.46, P = 0.002), whereas ASAT showed no relationship. Neck circumference correlated with both VAT (r(2) = 0.67, P < 0.0001) and HOMA-IR (r(2) = 0.35, P = 0.01). Waist circumference only correlated significantly with VAT (r(2) = 0.25, P = 0.03).
  
  
  CONCLUSIONS
  Visceral adiposity remains a strongly significant indicator of insulin resistance in WHO grade III obesity. Neck circumference surpasses other anthropometric measurements as a powerful marker of both VAT and insulin resistance.
authors.affiliation: Endocrinology Department, King's College Hospital, Denmark Hill, London, UK.
authors.forename: L
authors.initials: L
authors.lastname: Yang
authors.forename: Y P
authors.initials: YP
authors.lastname: Samarasinghe
authors.forename: P
authors.initials: P
authors.lastname: Kane
authors.forename: S A
authors.initials: SA
authors.lastname: Amiel
authors.forename: S J B
authors.initials: SJ
authors.lastname: Aylwin
mesh_terms: D050154:Adiposity / Q000502:physiology*; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D001837:Body Weights and Measures; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D050152:Intra-Abdominal Fat / Q000000981:diagnostic imaging / Q000473:pathology* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000033:anatomy & histology / Q000473:pathology*; D009767:Obesity, Morbid / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D014944:World Health Organization
chemical_list: D001786:Blood Glucose