Salt intake and hypertensive renal injury in African-Americans. A therapeutic perspective.

Hypertensive renal injury is a major identifiable cause of end-stage renal disease in African-Americans. A complex nexus of sociologic, biologic, environmental, and sociocultural variables are involved in mediating this risk and interrelate with dietary salt consumption and salt sensitivity. It is likely that dietary salt intake and salt sensitivity are linked in influencing the risk of hypertensive renal injury, since it has been demonstrated that increasing dietary salt in salt-sensitive patients such as African-Americans results in an increase in glomerular filtration fraction and proteinuria. Dietary salt likely influences both carbohydrate metabolism and blood pressure, either directly or through its influence on other ions such as calcium or potassium. The interrelationship between salt and pharmacologic interventions is an important clinical issue, since the efficacy of these therapies is influenced by the amount of salt in the diet. It is also likely that the changes in blood pressure and carbohydrate metabolism induced by greater dietary salt intake may be more specifically corrected by some nonpharmacologic or pharmacologic interventions compared to others. Since dietary salt has identifiable influences on blood pressure, renal hemodynamics, and carbohydrate metabolism, its overall effect on cardiovascular risk, particularly in high-risk groups such as African-Americans, assumes increasing importance.