Salt, hypertension, and genetic-environmental interactions.

Observations relating to hypertension in humans and rat experiments have been reviewed from several viewpoints including clinical medicine, pathophysiology, epidemiology, and genetics. It seems likely that much of essential hypertension results from excessive salt intake by individuals with an inherited inability to excrete sodium efficiently which is compensated by blood pressure elevation. A few major genes are likely responsible for a few basic mechanisms involving renal membranes and hormones controlling sodium transport. Excess hypertension in blacks, diabetics, the elderly, and oral contraceptive users can be explained by this theory. If hypertension and other genetically predisposed CHD risk factors are to be fully understood, future studies are needed with detailed data on both genetic and environmental factors, and analytic tools that allow an adequate examination of their interactions.