title: A cross-sectional characterization of insulin resistance by phenotype and insulin clamp in East Asian Americans with type 1 and type 2 diabetes.
abstract: OBJECTIVE
  Classic features of type 1 and type 2 diabetes may not apply in Asian Americans, due to shared absence of common HLA DR-DQ genotype, low prevalence of positive anti-islet antibodies and low BMI in both types of diabetes. Our objective was to characterize diabetic phenotypes in Asian Americans by clamp and clinical features.
  
  
  METHODS
  This was a cross-sectional study conducted in a referral center. Thirty East young Asian American adult volunteers (27.6±5.5 years) with type 1, type 2 diabetes or controls underwent hyperinsulinemic euglycemic clamp to assess insulin resistance and DEXA to assess adiposity.
  
  
  RESULTS
  Gender, BMI, waist/hip ratio, leptin, LDL, anti-GAD, anti-IA2 antibodies and C-reactive protein were similar among three groups. Serum C-peptide, adiponectin, free fatty acid, HDL concentrations and truncal fat by DEXA, were different between diabetic groups. Glucose disposal rate by clamp was lowest in type 2 diabetes, followed by type 1 diabetes and controls (5.43±2.70, 7.62±2.59, 8.61±2.37 mg/min/kg, respectively, p = 0.001). Free fatty acid concentration universally plummeted during steady state of the clamp procedure regardless of diabetes types in all three groups. Adipocyte fatty acid binding protein in the entire cohort (r = -0.625, p = 0.04) and controls (r = -0.869, p = 0.046) correlated best with insulin resistance, independent of BMI.
  
  
  CONCLUSIONS
  Type 2 diabetes in Asian Americans was associated with insulin resistance despite having low BMI as type 1 diabetes, suggesting a potential role for targeting insulin resistance apart from weight loss. Adipocyte fatty acid binding protein, strongly associated with insulin resistance, independent of adiposity in the young Asian American population, may potentially serve as a biomarker to identify at-risk individuals. Larger studies are needed to confirm this finding.
authors.affiliation: Asian American Diabetes Initiative, Joslin Diabetes Center, Boston, Massachusetts, United States of America. William.hsu@joslin.harvard.edu
authors.forename: William C
authors.initials: WC
authors.lastname: Hsu
authors.forename: Eyiuche
authors.initials: E
authors.lastname: Okeke
authors.forename: Sophia
authors.initials: S
authors.lastname: Cheung
authors.forename: Hillary
authors.initials: H
authors.lastname: Keenan
authors.forename: Tracy
authors.initials: T
authors.lastname: Tsui
authors.forename: Kyle
authors.initials: K
authors.lastname: Cheng
authors.forename: George L
authors.initials: GL
authors.lastname: King
mesh_terms: D050154:Adiposity; D000328:Adult; D001213:Asian; D015415:Biomarkers / Q000378:metabolism; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000208:ethnology*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000208:ethnology*; D005260:Female; D005838:Genotype; D015309:Glucose Clamp Technique / Q000379:methods; D006683:HLA-DQ Antigens / Q000737:chemistry*; D006684:HLA-DR Antigens / Q000737:chemistry*; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D008297:Male; D010641:Phenotype; D014481:United States
chemical_list: D015415:Biomarkers; D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; D007328:Insulin