Arterial stiffness and kidney function

The vascular hallmark of subjects with end-stage renal disease undergoing hemodialysis is increased aortic stiffness, a phenomenon independent of mean arterial blood pressure, wall stress, and standard cardiovascular risk factors such as plasma glucose, cholesterol, obesity, and smoking. These observations suggest that subtle links might associate arterial stiffness and kidney function in normotensive and hypertensive populations. Recently, aortic pulse wave velocity and creatinine clearance have been shown to be statistically associated in subjects with plasma creatinine < or =130 micromol/L, again independently of mean arterial blood pressure and classical cardiovascular risk factors. This association was even shown to predominate in subjects younger than age 55 years. In addition, acceleration of aortic pulse wave velocity with age was more important in these subjects than in untreated normotensive control individuals, and the phenomenon was consistently predicted by baseline plasma creatinine values. Among all antihypertensive drugs, angiotensin-converting enzyme inhibitors only were shown to exhibit a significant and independent effect on aortic stiffness. The use of these drugs was significantly associated with improvement of large aortic stiffness in subjects treated for hypertension. In conclusion, increased stiffness of central arteries is independently associated with reduced creatinine clearance in subjects with mild to severe renal insufficiency, indicating that kidney diseases may interact not only with small but also with large conduit arteries, independently of age, blood pressure level, and classical cardiovascular risk factors. Whether sodium, divalent ionic species (calcium, phosphates), and the renin-angiotensin-aldosterone system play a role in such alterations remains to be elucidated.