Blood pressure: Importance of the kidney and the need to reduce salt intake

The height of the blood pressure is one of the most important determinants of strokes and heart attacks, the two most common causes of death and disability in the western world. In undeveloped communities that do not have access to salt, blood pressure remains low throughout life in comparison with that in developed countries, where blood pressure is higher and increases inexorably with increasing age. An understanding of why blood pressure increases could lead to better preventive strategies, and thereby to a major reduction in cardiovascular disease. Much evidence suggests that salt intake plays an important role in elevating blood pressure. At the same time, elegant cross-transplantation experiments on inherited hypertension in rats and more circumstantial evidence in humans suggests that an inherited abnormality in the kidney, combined with our high salt intake, is likely to explain the development of high blood pressure in individuals. At the same time, studies now show that modest reductions in salt intake cause large decreases in blood pressure in hypertensive individuals and smaller, but very important from a public health perspective, decreases in blood pressure in normotensive people. A large effort is now required to persuade the salt, soft drink, and food manufacturers to reduce the unnecessarily high salt content of processed food. (C) 2001 by the National Kidney Foundation, Inc.