Serum fetuin-A in nondialyzed patients with diabetic nephropathy: Relationship with coronary artery calcification

Serum fetuin-A in nondialyzed patients with diabetic nephropathy: Relationship with coronary artery calcification.BackgroundFetuin-A is the most potent circulating inhibitor of calcium phosphorus precipitation and, possibly, an important mediator of insulin resistance.MethodsIn 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)].ResultsThe 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 (partialr = 0.33,P = 0.018). Furthermore, there was a significant direct relationship between serum fetuin-A and serum triglycerides (partialr = 0.27,P = 0.01) and albumin (partialr = 0.30,P = 0.005), and an inverse relationship with glomerular filtration rate (r=-0.24,P = 0.03).ConclusionThis 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