Diminished gastric inhibitory polypeptide response to oral glucose in late human pregnancy.

It has been shown that the incretin effect - i.e. the gastrointestinal potentiation of the insulin response to oral glucose - is reduced in late normal pregnancy. As evidence points to gastric inhibitory polypeptide (GIP) as mediator of at least part of the incretin effect, the GIP response was determined following a 50 g oral glucose load in 6 normal women in the last trimester of pregnancy and again post partum. Compared to post partum the GIP response to oral glucose was significantly impaired in late pregnancy. It is concluded that the diminished GIP response to oral glucose in late pregnancy might at least partly explain the impaired incretin effect found in this condition.