HYPERINSULINEMIA AND HYPERTENSION - DO INTESTINAL HORMONES PLAY A ROLE

Gastric inhibitory polypeptide (GIP) is one of the strongest insulinot ropic gut factors. Its secretion is induced by oral (but not intraveno us) glucose and it has been implicated in the pathogenesis of hyperins ulinemic states (NIDDM, obesity). To determine its relevance to hypert ension, 54 subjects were studied: 26 normotensives (12 with and 14 wit hout family history of essential hypertension), and 28 essential hyper tensive subjects. Plasma glucose, serum insulin (IRI), and GIP were ev aluated after a mixed meal containing a total of 82 g of carbohydrates , and 2 g sodium chloride. Venous blood was collected at baseline and every 15 min. during a 3-h period. Baseline levels of glucose, IRI, an d GIP were comparable in the three groups. At 30 min, however, IRI and GIP were higher in normotensives with a family history of hypertensio n and in established hypertensive versus control subjects. Both in nor motensive and in hypertensive groups, glucose, IRI, and GIP responses to the meal were significantly correlated. Our data suggest the contri bution of altered GIP secretion in the pathogenesis of hyperinsulinemi a in essential hypertension.