Increased intrahepatic triglyceride is associated with peripheral insulin resistance: in vivo MR imaging and spectroscopy studies

Am J Physiol Endocrinol Metab. 2007 Dec;293(6):E1663-9. doi: 10.1152/ajpendo.00590.2006. Epub 2007 Oct 2.

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adiponectin / blood
  • Adult
  • Chemokine CCL2 / blood
  • Glucose Clamp Technique
  • Humans
  • Insulin Resistance / physiology*
  • Interleukin-6 / blood
  • Intra-Abdominal Fat / metabolism
  • Leptin / blood
  • Lipid Metabolism
  • Lipids / analysis
  • Liver / chemistry*
  • Magnetic Resonance Imaging / methods*
  • Magnetic Resonance Spectroscopy / methods*
  • Male
  • Middle Aged
  • Muscle, Skeletal / metabolism
  • Resistin / blood
  • Subcutaneous Fat, Abdominal / metabolism
  • Triglycerides / analysis*
  • Tumor Necrosis Factor-alpha / blood

Substances

  • Adiponectin
  • CCL2 protein, human
  • Chemokine CCL2
  • Interleukin-6
  • Leptin
  • Lipids
  • Resistin
  • Triglycerides
  • Tumor Necrosis Factor-alpha