Serum fetuin-A in nondialyzed patients with diabetic nephropathy: relationship with coronary artery calcification.
BACKGROUND
Fetuin-A is the most potent circulating inhibitor of calcium phosphorus precipitation and, possibly, an important mediator of insulin resistance.


METHODS
In order to determine the role of fetuin-A in the high coronary artery calcification (CAC) burden seen in nondialyzed individuals with diabetic nephropathy (DN), post-hoc analyses of data collected from a cross-sectional study of 88 patients with type 2 diabetes mellitus was done [age, 40-65 years; normoalbuminuria, N= 30 (Latinos); DN, N= 58 (Latinos and African Americans)].


RESULTS
The serum levels of fetuin-A were significantly higher among Latinos with DN when compared to either African Americans with DN or Latino diabetics with normoalbuminuria. Upon adjusting the data for race/ethnicity, there was a strong, direct relationship between serum fetuin-A levels and the CAC score (r= 0.22, P= 0.038) in the study cohort; however, a strong interaction between the nephropathy status and relationship of serum fetuin-A levels with CAC score was present (DN: r= 0.36, P= 0.006; diabetic controls, r= 0.0, P= 0.98). Among individuals with DN, the significance of the association persisted even after controlling the data for other predictors of CAC (partial r= 0.33, P= 0.018). Furthermore, there was a significant direct relationship between serum fetuin-A and serum triglycerides (partial r= 0.27, P= 0.01) and albumin (partial r= 0.30, P= 0.005), and an inverse relationship with glomerular filtration rate (r=-0.24, P= 0.03).


CONCLUSIONS
This first study in early stages of diabetic chronic kidney disease shows that the role of serum fetuin-A may be far more complex than previously described. During predialysis stage of DN, there is a direct relationship between serum fetuin-A levels and CAC score. The reasons for this association in the presence of nephropathy are unclear, but may be secondary to proatherogenic insulin resistance.
Mehrotra
Rajnish
R
Division of Nephrology and Hypertension, Harbor-UCLA Medical Center, Torrance, California 90502, USA. rmehrotra@labiomed.org
Westenfeld
Ralf
R
Christenson
Peter
P
Budoff
Matthew
M
Ipp
Eli
E
Takasu
Junichiro
J
Gupta
Ajay
A
Norris
Keith
K
Ketteler
Markus
M
Adler
Sharon
S
D000328:Adult; D000368:Aged; D001798:Blood Proteins / Q000032:analysis*; D002114:Calcinosis / Q000097:blood*; D002908:Chronic Disease; D003327:Coronary Disease / Q000097:blood*; D003430:Cross-Sectional Studies; D003928:Diabetic Nephropathies / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D060749:alpha-2-HS-Glycoprotein
C556354:AHSG protein, human; D001798:Blood Proteins; D060749:alpha-2-HS-Glycoprotein