Hypertension and Insulin Resistance Syndrome

There is considerable evidence that abnormalities of glucose, insulin and lipoprotein metabolism occur more frequently in untreated hypertensive patients than in normotensive control subjects. When hypertensive patients are compared with age- and weight-matched normotensive control subjects, a heightened plasma insulin response to a glucose tolerance test is consistently found. The reason for the association of insulin resistance/hyperinsulinemia and essential hypertension can be sought in at least four general types of mechanisms: sodium retention, sympathetic nervous system activation, disturbed membrane ion transport and proliferation of vascular smooth muscle cells. In primary aldosteronism and renovascular hypertension, insulin sensitivity was augmented when compared with the control subjects. Therefore, the insulin resistance seems to be a specific characteristic in essential hypertension. Increased type lib muscle fiber or disturbed intracellular signal transduction may be associated with the mechanisms of insulin resistance in essential hypertensives.