Rol del riñón en la hipertensión sal-sensible / Role of the kidney in salt sensitive hypertension

An important proportion of patients with essential hypertension are salt sensitive, defined as those who experience signifcant blood pressure changes according to the amount of salt intake. They have a disturbance in the pressure induced natriuresis mechanism and their kidneys have functional and morphological alterations con-sistent with an acquired tubulointerstitial alteration, afferent arteriole damage and alteration of peritubular capillaries. All these alterations lead to disturbances in sodium load excretion under normal pressures. There is also an associated activation of kidney vasoconstrictor/salt retaining systems and a reduction in the vasodilator/ salt eliminating mechanisms. These alterations, that originate early in life, generate a new blood pressure level, that corrects natriuresis at the expense of a sustained hypertension.

Enfermedad renal en la diabetes: a propósito del día mundial del riñón: [editorial] / Diabetic renal disease: the World Kidney Day in Chile: [editorial]

The third version of the World Kidney Day will be held on May 13, 2010 in Chile and will be focused in diabetic renal damage, the main cause of chronic kidney disease (CKD). Currently, we are living a pandemia of CKD, a progressive and irreversible condition with high social and economic impact. In Chile, we have 857 patients per million inhabitants in hemodialysis and 35 percent are secondary to diabetes. Our general prevalence of diabetes is 4.2 percent, rising to 15 percent in people aged more than 64 years. With a 34 percent prevalence of hypertension, an aging population, high prevalence of obesity, and a sedentary lifestyle, there is an estimation of a rise in 85 percent of the prevalence of diabetes in South-America, for the next decades. The steps to be taken are clear: campaigns should be aimed at (1) prevention of type 2 diabetes; (2) screening for early diabetic kidney disease; (3) increasing patient awareness of kidney disease; (4) using medications of proven strategy and fnally (5) research on new therapies. These concepts must be included in community and professional education to reduce the effects of this pandemia.

Daño vascular en la enfermedad renal crónica: [revisión] / Vascular damage in chronic kidney disease: [review]

Cardiovascular disease is a frequent complication of renal failure and is the most common cause of death in patients with chronic kidney disease (CKD). Accelerated atherogenesis has been widely documented in CKD and diabetic nephropathy is the leading cause of renal failure worldwide. Furthermore, CKD promotes hypertension and dyslipidemia, which in turn may contribute to the progression of renal failure. All together, hypertension, dyslipidemia and diabetes are considered major risk factors for the development of endothelial dysfunction and progression of atherosclerosis. Elevated inflammatory mediators and activation of the renin-angiotensin system contribute through enhanced production of reactive oxygen species, to atherogenesis in CKD. Vascular calcification is also important. Calcification of arteries occurs in the intima in association with atherosclerosis, where it may contribute to plaque formation, and in the media, where it causes stiffening. Increased serum levels of calcification promoters, such as hyperphosphatemia, and a decrease in circulating and local inhibitors of calcification, favor vascular calcification. On the other hand, transdifferentiation of vascular smooth muscle cells to osteblast-like cells would be the pivotal event in calcification. Bone morphogenetic protein agonists and antagonists are playing a role in this osteogenic differentiation. Accelerated atherosclerosis and media calcification will then lead to increased prevalence of coronary artery disease, heart failure, stroke, and peripheral arterial disease. Prevention and treatment of cardiovascular disease are major considerations in the management of individuals with CKD.