Body composition, blood pressure and the renin-angiotensin system in acromegaly before and after treatment.

Serial measurements of exchangeable sodium (Nae), blood pressure, circulating concentrations of growth hormone and the components of the renin-angiotensin-aldosterone system were made in 39 acromegalic patients: 26 patients were studied before and after treatment. Mean Nae was considerably increased, frequently being greater than values found in Conn's syndrome. Nine of the 26 untreated patients were hypertensive (35%) and of these seven were female and over the age of 52 years. In the untreated patients, Nae was positively correlated with age, blood pressure and growth hormone log concentration: the strongest correlation between Nae and growth hormone was obtained when the duration of the acromegalic process was taken into account. Following treatment there was often considerable reduction in Nae and this correlated closely with the fall in growth hormone: the relation between the fall in Nae and fall in blood pressure was less marked. The sodium retaining properties of growth hormone may cause a rise of blood pressure in a susceptible minority of acromegalics.