Gastric inhibitory polypeptide, insulin and glucose responses to a standard breakfast in controls and in patients with proximal gastric vagotomy or with vagotomy and pyloroplasty

ABSTRACT

To study the importance of the vagus nerve on handling the carbohydrate metabolism in vagotomised patients. Method: Eleven control subjects after truncal vagotomy and pyloroplasty were investigated. Plasma glucose, insulin and gastric inhibitory polypeptide concentrations were measured before and for 180 minutes following a standard meal Plasma glucose concentration was measured by the glucose oxides method and insulin and Gastric Inhibitory Polypeptide [GIP] concentrations were determined using radioimmunoassay methods. Compared to mean basal values, plasma glucose concentrations in control subjects were high from 15 to 45 minutes after the breakfast whereas in patients with Proximal Gastric Vagotomy [PGV] of Vagotomy and Pyloroplasty [V and P] they were significantly higher for 15 and 30 minutes. Plasma insulin and GIP concentrations of all three groups were higher from 15 to 180 minutes after the breakfast compared to their mean basal values. Patients with V and P had a lower glucose response at 45 minutes after the breakfast compared to the controls. Both groups of patients had similar insulin but significantly lower GIP responses compared to the control subjects. Proximal gastric vagotomy affects GIP responses and vagotomy and pyloroplasty can affect the pattern of glucose, and GIP responses to a standard breakfast compared to control subjects: