Intrahepatic Fat Accumulation and Alterations in Lipoprotein Composition in Obese Adolescents

A perfect proatherogenic state

  1. Anna M.G. Cali, MD1,
  2. Tosca L. Zern, PHD1,
  3. Sara E. Taksali, MPH1,
  4. Ana Mayra de Oliveira, MD2,
  5. Sylvie Dufour, PHD3,
  6. James D. Otvos, PHD4 and
  7. Sonia Caprio, MD1
  1. 1Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
  2. 2Department of Health, State University of Feira de Santana, Feira De Santana, Brazil
  3. 3Department of Internal Medicine and the Howard Hughes Institute, Yale University School of Medicine, New Haven, Connecticut
  4. 4LipoScience, Raleigh, North Carolina
  1. Address correspondence and reprint requests to Sonia Caprio, MD, Yale University School of Medicine, Department of Pediatrics, 330 Cedar St., P.O. Box 208064, New Haven, CT 06520. E-mail: sonia.caprio{at}yale.edu

Abstract

OBJECTIVE—Among other metabolic consequences, a dyslipidemic profile often accompanies childhood obesity. In adults, type 2 diabetes and hepatic steatosis have been shown to alter lipoprotein subclass distribution and size; however, these alterations have not yet been shown in children or adolescents. Therefore, our objective was to determine the effect of hepatic steatosis on lipoprotein concentration and size in obese adolescents.

RESEARCH DESIGN AND METHODS—Using fast magnetic resonance imaging, we measured intrahepatic fat content in 49 obese adolescents with normal glucose tolerance. The presence or absence of hepatic steatosis was determined by a threshold value for hepatic fat fraction (HFF) of 5.5%; therefore, the cohort was divided into two groups (HFF > or <5.5%). Fasting lipoprotein subclasses were determined using nuclear magnetic resonance spectroscopy.

RESULTS—Overall, the high-HFF group had 88% higher concentrations of large VLDL compared with the low-HFF group (P < 0.001). Likewise, the high-HFF group had significantly higher concentrations of small dense LDL (P < 0.007); however, the low-HFF group had significantly higher concentrations of large HDL (P < 0.001). Stepwise multiple regression analysis revealed that high HFF was the strongest single correlate, accounting for 32.6% of the variance in large VLDL concentrations (P < 0.002).

CONCLUSIONS—The presence of fatty liver was associated with a pronounced dyslipidemic profile characterized by large VLDL, small dense LDL, and decreased large HDL concentrations. This proatherogenic phenotype was strongly related to the intrahepatic lipid content.

Footnotes

  • Published ahead of print at http://care.diabetesjournals.org on 23 August 2007. DOI: 10.2337/dc07-1088.

    A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.

    The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C Section 1734 solely to indicate this fact.

    • Accepted August 17, 2007.
    • Received June 7, 2007.
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  1. Diabetes Care vol. 30 no. 12 3093-3098
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