title: Ethnic differences in insulin sensitivity, β-cell function, and hepatic extraction between Japanese and Caucasians: a minimal model analysis.
abstract: BACKGROUND
  Ethnic differences have previously been reported for type 2 diabetes.
  
  
  OBJECTIVE
  We aimed at assessing the potential differences between Caucasian and Japanese subjects ranging from normal glucose tolerance (NGT) to impaired glucose tolerance (IGT) and to type 2 diabetes.
  
  
  METHODS
  This was a cross-sectional study with oral glucose tolerance tests to assess β-cell function, hepatic insulin extraction, and insulin sensitivity.
  
  
  METHODS
  PARTICIPANTS included 120 Japanese and 150 Caucasian subjects.
  
  
  RESULTS
  Measures of β-cell function, hepatic extraction, and insulin sensitivity were assessed using C-peptide, glucose, and insulin minimal models.
  
  
  RESULTS
  Basal β-cell function (Φ(b)) was lower in Japanese compared with Caucasians (P < .01). In subjects with IGT, estimates of the dynamic (Φ(d)) and static (Φ(s)) β-cell responsiveness were significantly lower in the Japanese compared with Caucasians (P < .05). In contrast, values of insulin action showed higher sensitivity in the Japanese IGT subjects. Hepatic extraction was similar in NGT and IGT groups but higher in Japanese type 2 diabetic subjects (P < .01). Despite differences in insulin sensitivity, β-cell function, and hepatic extraction, the disposition indices were similar between the 2 ethnic groups at all glucose tolerance states. Furthermore, the overall insulin sensitivity and β-cell responsiveness for all glucose tolerance states were similar in Japanese and Caucasians after accounting for differences in body mass index.
  
  
  CONCLUSIONS
  Our study provides evidence for a similar ability of Japanese and Caucasians to compensate for increased insulin resistance.
authors.affiliation: Novo Nordisk A/S (J.B.M., R.V.O., S.H.I., C.W.T., J.L., N.-M.V.), 2880 Bagsvaerd, Denmark; Department of Information Engineering (C.D.M., C.C.), Universita di Padova, 35131 Padova, Italy; The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research (M.P., B.K.P.), Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark; and Department of Metabolic Diseases (H.T., M.O., K.U., T.K.), Graduate School of Medicine, University of Tokyo, 113-8654 Tokyo, Japan.
authors.forename: Jonas B
authors.initials: JB
authors.lastname: Møller
authors.forename: Chiara
authors.initials: C
authors.lastname: Dalla Man
authors.forename: Rune V
authors.initials: RV
authors.lastname: Overgaard
authors.forename: Steen H
authors.initials: SH
authors.lastname: Ingwersen
authors.forename: Christoffer W
authors.initials: CW
authors.lastname: Tornøe
authors.forename: Maria
authors.initials: M
authors.lastname: Pedersen
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Tanaka
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ohsugi
authors.forename: Kohjiru
authors.initials: K
authors.lastname: Ueki
authors.forename: Jan
authors.initials: J
authors.lastname: Lynge
authors.forename: Nina-Maria
authors.initials: NM
authors.lastname: Vasconcelos
authors.forename: Bente K
authors.initials: BK
authors.lastname: Pedersen
authors.forename: Takashi
authors.initials: T
authors.lastname: Kadowaki
authors.forename: Claudio
authors.initials: C
authors.lastname: Cobelli
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D001786:Blood Glucose; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000208:ethnology* / Q000503:physiopathology; D005260:Female; D018149:Glucose Intolerance / Q000097:blood / Q000208:ethnology / Q000503:physiopathology; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000208:ethnology*; D050417:Insulin-Secreting Cells / Q000502:physiology*; D007564:Japan; D008099:Liver / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D044465:White People
chemical_list: D001786:Blood Glucose; D007328:Insulin