Advanced glycation end products and arterial stiffness in patients with diabetic nephropathy and patients with chronic kidney disease without diabetes

INTRODUCTION Formation of advanced glycation end‑products (AGEs) is increased in diabetic patients. Impaired renal function also elevates AGE accumulation. Pulse wave velocity (PWV) is a measure of arterial stiffness and a prognostic parameter. An association between AGEs and arterial stiffness was observed in hemodialyzed patients.
OBJECTIVES We investigated the relationship between plasma AGE concentration and arterial stiffness in nondialyzed patients with diabetic nephropathy and those with chronic kidney disease (CKD) without diabetes.
PATIENTS AND METHODS PWV measurement was performed in 24 patients with CKD and diabetic nephropathy (DN), 36 patients with CKD and without diabetes, and 19 controls. To assess AGE concentrations, plasma fluorescence spectra were recorded. 
RESULTS Patients with and without diabetes did not differ with respect to the glomerular filtration rate (33 ±13 vs. 32 ±14 ml/min/1.73 m2, respectively). The AGE concentration was significantly higher in patients with DN compared with those without diabetes and controls (21.1 ±6.8 vs. 12.3 ±3.1 vs. 7.8 ±1.2 AU/ml, respectively; P <0.001). PWV was also significantly higher in patients with DN compared with those without diabetes and controls (13.7 ±4.3 vs. 10.1 ±2.4 vs. 8.4 ±1.6 m/s, respectively; P <0.05). A significant correlation was found between AGEs and PWV (r = 0.39, P <0.01) in patients with CKD. In a multiple regression analysis, PWV was independently associated with age, DN, and systolic blood pressure, but not with AGEs (R2 = 0.45). 
CONCLUSIONS Accumulation of AGEs and arterial stiffness are increased in patients with CKD, particularly in those with DN; however, the results are not sufficient to confirm the causal role of AGE accumulation in arterial stiffening in CKD. AGEs should be considered as a potential therapeutic target in patients with CKD.