Plasma insulin response following oral and intravenous glucose in pregnant diabetic women.

The acute release of insulin in most pregnant diabetic patients is sluggish. A study was undertaken to determine whether this abnormality was due to a relative insensitivity of the beta cell to glucose or to an attenuation of the enteroinsular axis. The plasma insulin response to intravenous and oral glucose was studied in third trimester pregnant insulin-independent diabetic and normal control patients. The results suggest that the sensitivity of beta cell reaction to glucose in the diabetic group was reduced and that this may be related in part to a defective enteroinsular response. Quantitative endocrine hypofunction, as evidenced by lowered plasma insulin levels, was also noted among the pregnant diabetic patients. The results are discussed in relation to the pathogenesis of disturbed carbohydrate metabolism in insulin-independent pregnant diabetic patients.