Blood Volume and Exchangeable Sodium in Essential Hypertension

Abstract 1. No significant difference in total blood volume was demonstrated between patients with untreated essential hypertension and normotensive controls. In hypertensive women the mean blood volume was 2317 ml/m 2 or 63.0 ml/kg as against 2259 ml/m 2 or 59.2 ml/kg in controls. The corresponding figures for hypertensive men were 2768 ml/m 2 or 67.1 ml/kg and 2591 ml/m 2 or 66.0 ml/kg for controls. 2. Exchangeable sodium was significantly increased in men with essential hypertension, 1736 mEq/m 2 or 42.4 mEq/kg, while 1639 mEq/m 2 or 39.2 mEq/kg was found in normotensive controls. Increased exchangeable sodium was also demonstrated in hypertensive women, 1502 mEq/m 2 or 41.2 mEq/kg in comparison with normotensive controls, whose values were 1445 mEq/m 2 or 39.9 mEq/kg. However, because of a difference in height and weight between the hypertensive and the normotensive women, the rsults must be taken with reservation.