['Serum Fetuin A has been identified as an inhibitor of ectopic calcification. It is reduced in subjects with chronic kidney disease (CKD) and it has been proposed as a potential link between CKD and the higher prevalence of arterial calcification observed in these patients. During aging both the stiffening of arterial wall due to calcification and a decline in kidney function are frequent. The aim of the study is to investigate if Fetuin A serum levels are associated with aging and with AHSG T256S polymorphism. Moreover, we aim at investigate whether serum Fetuin A is correlated to kidney function in this setting of senescence.', '256 health long-lived subjects (age 92 [81-100]) were recruited for the study. Serum Fetuin A was evaluated by ELISA, Cystatin C by immune-nephelometry. AHSG T256S was determinated by PCR-RFLP.', 'Serum Fetuin A shows a significant correlation with age (r=0.20; P=0.0048). AHSG TS and SS genotypes are associated to lower levels of serum protein (0.27 [0.19-0.29] g/L vs 0.42 [0.32-0.49] g/L; P<0.027 and 0.34 [0.25-0.41] g/L vs 0.42 [0.32-0.49] g/L; P<0.001, respectively). No significant correlation between Fetuin A and Cystatin C was observed.'] Are fetuin-A serum levels correlated to kidney function in long-lived subjects?