GIP and insulin responses to oral glucose in coeliac patients before and after treatment.

The responses of plasma gastric inhibitory polypeptide (GIP) and insulin to oral glucose were studied in five patients with untreated coeliac disease. These patients were restudied after one year on a gluten-free diet. In the untreated patients, the blood glucose, serum insulin, and GIP levels were significantly lower than in the controls. After gluten withdrawal there was an improvement towards normality in the responses of blood glucose, serum insulin, and GIP. The results show that untreated coeliac disease is associated with abnormalities of intestinal and pancreatic hormone secretion and that these abnormalities are improved by gluten withdrawal.