Serum Vaspin Concentrations in Human Obesity and Type 2 Diabetes Byung-Soo Youn 1 2 , Nora Klöting 3 , Jürgen Kratzsch 4 , Namseok Lee 1 , Ji Woo Park 1 , Eun-Sun Song 1 , Karen Ruschke 3 , Andreas Oberbach 3 , Mathias Fasshauer 3 , Michael Stumvoll 3 and Matthias Blüher 3 1 AdipoGen, College of Life Science and Biotechnology, Korea University, Seoul, Korea 2 Immunomodulation Research Center, University of Ulsan, Ulsan, Korea 3 Department of Medicine, University of Leipzig, Leipzig, Germany 4 Institute of Clinical Chemistry and Pathobiochemistry, University of Leipzig, Leipzig, Germany Address correspondence and reprint requests to Matthias Blüher, MD, University of Leipzig, Department of Medicine, Ph.-Rosenthal-Str. 27, 04103 Leipzig, Germany. E-mail: bluma{at}medizin.uni-leipzig.de ; or Byung S. Youn, PhD, Scientific Director, AdipoGen. E-mail: bsyoun{at}adipogen.com Abstract OBJECTIVE— Vaspin was identified as an adipokine with insulin-sensitizing effects, which is predominantly secreted from visceral adipose tissue in a rat model of type 2 diabetes. We have recently shown that vaspin mRNA expression in adipose tissue is related to parameters of obesity and glucose metabolism. However, the regulation of vaspin serum concentrations in human obesity and type 2 diabetes is unknown. RESEARCH DESIGN AND METHODS— For the measurement of vaspin serum concentrations, we developed an enzyme-linked immunosorbent assay (ELISA). Using this ELISA, we assessed circulating vaspin in a cross-sectional study of 187 subjects with a wide range of obesity, body fat distribution, insulin sensitivity, and glucose tolerance and in 60 individuals with normal glucose tolerance (NGT), impaired glucose tolerance (IGT), or type 2 diabetes before and after a 4-week physical training program. RESULTS— Vaspin serum concentrations were significantly higher in female compared with male subjects. There was no difference in circulating vaspin between individuals with NGT and type 2 diabetes. In the normal glucose-tolerant group, circulating vaspin significantly correlated with BMI and insulin sensitivity. Moreover, physical training for 4 weeks resulted in significantly increased circulating vaspin levels. CONCLUSIONS— We found a sexual dimorphism in circulating vaspin. Elevated vaspin serum concentrations are associated with obesity and impaired insulin sensitivity, whereas type 2 diabetes seems to abrogate the correlation between increased circulating vaspin, higher body weight, and decreased insulin sensitivity. Low circulating vaspin correlates with a high fitness level, whereas physical training in untrained individuals causes increased vaspin serum concentrations. ELISA, enzyme-linked immunosorbent assay HEK, human embryonic kidney IGT, impaired glucose tolerance NGT, normal glucose tolerance OGTT, oral glucose tolerance test PAI-1, plasminogen activator inhibitor type 1 Footnotes Published ahead of print at http://diabetes.diabetesjournals.org on 8 November 2007. DOI: 10.2337/db07-1045. Additional information for this article can be found in an online appendix at http://dx.doi.org/10.2337/db07-1045 . B.-S.Y. and N.K. contributed equally to this work. 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 November 3, 2007. Received July 28, 2007. DIABETES