High blood pressure and hyperinsulinaemia in acromegaly and in obesity

As previously shown, in essential hypertension postprandial plasma insulin concentrations are elevated. In order to determine a relationship of high blood pressure and plasma insulin levels in acromegaly and in obesity 59 subjects with normal glucose tolerance were studied. They were divided into three groups: (I) patients with acromegaly: 7 normotensives and 8 hypertensives, (II) 12 obese normotensives and 12 obese hypertensives and (III) 10 non-obese hypertensives, and 10 healthy subjects. Blood glucose and plasma insulin concentrations were measured in a fasting state and after an oral glucose load of 75 g. The fasting insulin concentrations in all the acromegalics and in all the obese patients were higher than those in healthy subjects. The insulin response to the glucose load was significantly enhanced in all the three groups of hypertensive patients compared with those of matched normotensive controls. The results indicate that insulin may play a role in the regulation of blood pressure in essential hypertension, and in such hyperinsulinaemic disorders as acromegaly and obesity.