Selective Downregulation of the High–Molecular Weight Form of Adiponectin in Hyperinsulinemia and in Type 2 Diabetes

Differential Regulation From Nondiabetic Subjects

  1. Rita Basu1,
  2. Utpal B. Pajvani2,
  3. Robert A. Rizza1 and
  4. Philipp E. Scherer234
  1. 1Division of Endocrinology, Metabolism, and Nutrition, Department of Medicine, Mayo Clinic and Foundation, Rochester, Minnesota
  2. 2Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York
  3. 3Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York
  4. 4Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York
  1. Address correspondence and reprint requests to Rita Basu, MD, Mayo Clinic, 200 1st St. SW, Room 5-194 Joseph, Rochester, MN 55905. E-mail: basu.rita{at}mayo.edu

Abstract

OBJECTIVE—Adiponectin is an adipocyte-specific secretory protein found in circulation in several different forms and is present at significantly lower levels in the plasma of diabetic patients compared with that of insulin-sensitive individuals. We wanted to test whether insulin per se is a contributing factor toward lower plasma adiponectin concentrations and, if so, whether the splanchnic bed contributes to this phenomenon.

RESEARCH DESIGN AND METHODS—We sampled femoral artery and hepatic venous samples and measured the high–molecular weight (HMW) and low–molecular weight (LMW) fractions of adiponectin in 11 type 2 diabetic and 7 nondiabetic subjects matched for age, sex, and BMI during basal conditions and during a hyperglycemic (∼9.5 mmol/l) hyperinsulinemic (∼700 pmol/l) clamp.

RESULTS—Under these conditions, total arterial adiponectin, HMW, and the ratio of HMW to total adiponectin all were lower (P < 0.01) in the diabetic versus nondiabetic subjects, whereas the LMW form did not significantly differ. Under hyperinsulinemic conditions, total adiponectin levels dropped, primarily due to a reduction of the HMW form, whereas LMW forms were not significantly affected.

CONCLUSIONS—HMW adiponectin and the ratio of HMW to total adiponectin are lower in individuals with diabetes than in nondiabetic subjects. We conclude that HMW adiponectin is downregulated in hyperinsulinemia and type 2 diabetes.

Footnotes

  • Published ahead of print at http://diabetes.diabetesjournals.org on 18 May 2007. DOI: 10.2337/db07-0185.

    U.B.P. is currently affiliated with the Department of Internal Medicine, Columbia University and New York-Presbyterian Hospital, New York, New York. P.E.S. is currently affiliated with the Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas.

    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 May 2, 2007.
    • Received February 9, 2007.
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  1. Diabetes vol. 56 no. 8 2174-2177
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