title: Increased intrahepatic triglyceride is associated with peripheral insulin resistance: in vivo MR imaging and spectroscopy studies.
abstract: Recent studies have indicated that the mass/content of intramyocellular lipid (IMCL), intrahepatic triglyceride (IHTG), visceral fat (VF), and even deep abdominal subcutaneous fat (SF) may all be correlated with insulin resistance. Since simultaneous measurements of these parameters have not been reported, the relative strength of their associations with insulin action is not known. Therefore, the goals of this study were 1) to simultaneously measure IMCL, IHTG, VF, and abdominal SF in the same nondiabetic individuals using noninvasive (1)H-magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) and 2) to examine how these fat stores are correlated with systemic insulin sensitivity as measured by whole body glucose disposal (R(d)) during euglycemic-hyperinsulinemic clamp studies. Positive correlations were observed among IMCL, IHTG, and VF. There were significant inverse correlations between whole body R(d) and both IMCL and VF. Notably, there was a particularly tight inverse correlation between IHTG and whole body R(d) (r = -0.86, P < 0.001), consistent with an association between liver fat and peripheral insulin sensitivity. This novel finding suggests that hepatic triglyceride accumulation has important systemic consequences that may adversely affect insulin sensitivity in other tissues.
authors.affiliation: Gruss MRRC Rm. No. 213, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461, USA. jhhwang@aecom.yu.edu
authors.forename: Jong-Hee
authors.initials: JH
authors.lastname: Hwang
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Stein
authors.forename: Nir
authors.initials: N
authors.lastname: Barzilai
authors.forename: Min-Hui
authors.initials: MH
authors.lastname: Cui
authors.forename: Julia
authors.initials: J
authors.lastname: Tonelli
authors.forename: Preeti
authors.initials: P
authors.lastname: Kishore
authors.forename: Meredith
authors.initials: M
authors.lastname: Hawkins
mesh_terms: D052242:Adiponectin / Q000097:blood; D000328:Adult; D018932:Chemokine CCL2 / Q000097:blood; D015309:Glucose Clamp Technique; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D015850:Interleukin-6 / Q000097:blood; D050152:Intra-Abdominal Fat / Q000378:metabolism; D020738:Leptin / Q000097:blood; D050356:Lipid Metabolism; D008055:Lipids / Q000032:analysis; D008099:Liver / Q000737:chemistry*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism; D052243:Resistin / Q000097:blood; D050507:Subcutaneous Fat, Abdominal / Q000378:metabolism; D014280:Triglycerides / Q000032:analysis*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D052242:Adiponectin; C111835:CCL2 protein, human; D018932:Chemokine CCL2; D015850:Interleukin-6; D020738:Leptin; D008055:Lipids; D052243:Resistin; D014280:Triglycerides; D014409:Tumor Necrosis Factor-alpha