IGF-Binding Protein-1 Levels Are Related to Insulin-Mediated Glucose Disposal and Are a Potential Serum Marker of Insulin Resistance
- Betty A. Maddux, BS1,
- Adelene Chan, BS1,
- Lawrence J. Mandarino, PHD2,
- Ira D. Goldfine, MD1 and
- Elena A. De Filippis, MD2
- 1Diabetes Center, Department of Medicine, University of California, San Francisco, California
- 2School of Life Science, Arizona State University, Tempe, Arizona
- Address correspondence and reprint requests to Betty A. Maddux, University of California, San Francisco, 2200 Post, C415, San Francisco, CA 94143-1616. E-mail: bmaddux{at}itsa.ucsf.edu
Abstract
OBJECTIVE—IGF-binding protein (IGFBP)-1 is negatively regulated by insulin. We determined whether the measurement of IGFBP-1 in serum is a useful marker of insulin resistance.
RESEARCH DESIGN AND METHODS—Twenty-three subjects underwent a euglycemic insulin clamp. Glucose disposal rates (M) were then correlated with measurements of IGFBP-1, fasting insulin levels, homeostasis model assessment (HOMA), and BMI.
RESULTS—IGFBP-1 levels more strongly correlated with M (R = 0.73) than the other parameters such as BMI or HOMA. The level of this protein decreased in individuals who became more insulin sensitive by exercise training.
CONCLUSIONS—These studies show a strong correlation between insulin sensitivity and the serum levels of IGFBP-1. These studies suggest, therefore, that measurement of this protein may be valuable in identifying those individuals with insulin resistance and those individuals who respond to interventional strategies.
Footnotes
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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.
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- Accepted April 7, 2006.
- Received July 22, 2005.
- DIABETES CARE
