Serum ionized calcium, parathormone and plasma renin activity in essential arterial hypertension

Given the significance of the calcium ion in the pathogenesis of essential arterial hypertension, blood levels of total and ionised calcium, phosphorus, parathormone, blood renin activity as well as urinary calcium and phosphorus were assayed in a group of hypertensives and a comparable control group with normal blood pressure. The results showed reduced ionised calcium in the blood of the hypertensives together with hyperparathyroidism and increased calciuria. In addition, the link between parathormone and mean blood pressure levels suggests that parathormone itself play a primary role in the genesis of high blood pressure. Finally the connection between renin activity in the plasma and ionised calcium in the serum suggests that the two hormone systems are closely linked and may interact via the calcium ion.