REN and chronic kidney disease: Moreover, several studies have suggested that arterial stiffness itself may also contribute to the progression of CKD.6–8 Arterial stiffness in CKD patients is of multifactorial etiologies including old age, vascular calcification, hypertension, inflammation, uremic toxins, and the renin-angiotensin-aldosterone system.9 Recent studies have identified accumulation of advanced glycation end products (AGEs) as a novel contributor to arterial stiffening.