Sodium Sensitivity in Normotensive Human Subjects

Compelling evidence implicates a high sodium intake in the development and maintenance of arterial hypertension. However, dietary sodium restriction reduces blood pressure in only a fraction of hypertensive patients. Studies in normotensive persons suggest that blacks and older persons excrete a sodium load less efficiently than persons of the same sex and race who are also matched for body weight and body surface area. Blacks show a greater natriuresis and decrease in blood pressure in response to volume contraction with furosemide administration than whites. These observations are consistent with an intrinsic renal abnormality in blacks and older persons, resulting in modest volume expansion. Such changes may contribute to sodium sensitivity and promote the development and maintenance of hypertension in persons with a high sodium intake.