Serum fetuin-A is an independent marker of insulin resistance in Japanese men.
OBJECTIVE
Fetuin-A, also known as alpha2-Heremans Schmid glycoprotein, is an abundant plasma protein synthesized predominantly in the liver. Fetuin-A inhibits insulin receptor autophosphorylation, which is mediated by its intrinsic tyrosine kinase activity. In this study, we examined the association between the serum fetuin-A level and insulin resistance in Japanese men.


METHODS
We recruited 300 unrelated Japanese men without known chronic diseases, such as diabetes mellitus, or a history of regular drug use, and who underwent health examinations. From a 75-g oral glucose tolerance test, the study population included 194 individuals with normal glucose tolerance, 91 with impaired glucose tolerance and/or impaired fasting glucose, and 15 with diabetes mellitus. Serum fetuin-A concentrations were measured using an ELISA kit.


RESULTS
Serum fetuin-A concentrations were positively correlated with fasting insulin levels (r = 0.269, p<0.001), HOMA-IR (r = 0.274, p<0.001) and LDL-cholesterol (r = 0.172, p<0.01), and negatively correlated with HDL-cholesterol concentrations (r = -0.191, p<0.001). Fetuin-A concentrations were also positively correlated with serum leptin (r = 0.150, p<0.01) and negatively with adiponectin concentrations (r = -0.208, p<0.001). Stepwise regression analyses confirmed that the fetuin-A concentration was independently associated with the fasting insulin level and HOMA-IR, as were body mass index, triglyceride, LDL-cholesterol, leptin and adiponectin concentrations.


CONCLUSIONS
Our data suggest that increased serum fetuin-A levels constitute an independent marker of insulin resistance and an atherogenic lipid profile in Japanese men.
Ishibashi
Ayako
A
Department of Endocrinology, Metabolism and Nephrology, Kochi Medical School, Kochi University, Kochi, Japan.
Ikeda
Yukio
Y
Ohguro
Takashi
T
Kumon
Yoshitaka
Y
Yamanaka
Shigeo
S
Takata
Hiroshi
H
Inoue
Mari
M
Suehiro
Tadashi
T
Terada
Yoshio
Y
D052242:Adiponectin / Q000097:blood; D050154:Adiposity / Q000502:physiology; D000328:Adult; D000368:Aged; D044466:Asian People; D050197:Atherosclerosis / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001798:Blood Proteins / Q000378:metabolism*; D002097:C-Reactive Protein / Q000378:metabolism; D003920:Diabetes Mellitus / Q000097:blood; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D007564:Japan; D020738:Leptin / Q000097:blood; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D060749:alpha-2-HS-Glycoprotein
C499918:ADIPOQ protein, human; C556354:AHSG protein, human; D052242:Adiponectin; D015415:Biomarkers; D001798:Blood Proteins; D020738:Leptin; D008055:Lipids; D060749:alpha-2-HS-Glycoprotein; D002097:C-Reactive Protein