[Arterial hypertension, chronic renal insufficiency and dialysis].

The principal characteristic of hypertension in chronic kidney disease (CKD), especially at CKD stage 5. Is an increased systolic pressure, with normal or even low diastolic pressure. This isolated systolic hypertension is also characterized by ab abnormal increase in pulse pressure which is by itself an independent cardiovascular risk factor. The principal reason for these abnormalities is accelerated ageing of arterial system, principally the aorta and large central arteries. This ageing is characterized by stiffening of arteritis whose natural history is not clearly understood. One of the principal pathogenic factor associated with stiffening is extensive calcification of arterial walls, mainly the medial layer (media-calcinosis). Mineral metabolism disorders such as hyperphosphatemia, play a major role in pathophysiology of calcifications. Arterial stiffness is characterized by very steep volume-pressure relationship and for this reason is associated with hemodynamic instability. Small blood volume increase producing abnormally high pressure while small decrease in blood volume could be associated with deep hypotension.