title: Increased adipose tissue insulin resistance in metabolic syndrome: relationship to circulating adipokines.
abstract: BACKGROUND
  Although hepatic insulin resistance has been documented in patients with metabolic syndrome using homeostasis model assessment of insulin resistance (HOMA-IR) as a measure, there is scanty data on adipose insulin resistance (Adipo-IR) and its relationship with the dysregulation of adipokines in metabolic syndrome. Thus, we examined whether Adipo-IR is increased in metabolic syndrome as well as its correlation with circulating adipokines.
  
  
  METHODS
  In 42 individuals including controls and participants with metabolic syndrome, we measured fasting plasma insulin and free fatty acids (FFA). Adipo-IR was calculated as the product of FFA×insulin. We examined the association between Adipo-IR, metabolic syndrome variables, and circulating adipokines, including leptin, adiponectin, chemerin, omentin-1, and retinol-binding protein-4.
  
  
  RESULTS
  Adipo-IR was higher in metabolic syndrome (n=19; median 68.7 mmol/L·pmol/L; 25(th)-75(th) percentile, 50.0-104.7) compared to controls (n=23; 22.9 mmol/L·pmol/L; 6.8-36.1; P<0.0001), and this difference was similar following adjustments for waist circumference or body mass index (BMI). Adipo-IR correlated significantly with certain adipokines: Leptin, r=0.45, P=0.004; adiponectin, r=-0.33, P<0.05; chemerin r=0.55, P=0.0008; omentin-1, r=-0.46, P=0.04, and with all features of metabolic syndrome.
  
  
  CONCLUSIONS
  Adipo-IR is increased in metabolic syndrome following adjustment for adiposity and may be an important biomarker of adipose tissue dysregulation, including adipokine secretion and a potential relevant therapeutic target.
authors.affiliation: 1 Department of Clinical Sciences, University of Texas Southwestern Medical Center , Dallas, Texas.
authors.forename: Beverley
authors.initials: B
authors.lastname: Adams-Huet
authors.forename: Sridevi
authors.initials: S
authors.lastname: Devaraj
authors.forename: David
authors.initials: D
authors.lastname: Siegel
authors.forename: Ishwarlal
authors.initials: I
authors.lastname: Jialal
mesh_terms: D054392:Adipokines / Q000097:blood*; D000273:Adipose Tissue / Q000378:metabolism* / Q000503:physiopathology; D050154:Adiposity; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D016022:Case-Control Studies; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology; D008875:Middle Aged; D055105:Waist Circumference; D055815:Young Adult
chemical_list: D054392:Adipokines; D015415:Biomarkers; D005230:Fatty Acids, Nonesterified; D007328:Insulin