Carbohydrate metabolism in pregnancy. XIV. Relationships between circulating glucagon, insulin, glucose and amino acids in response to a "mixed meal" in late pregnancy

Gestational influences upon the changes in circulating glucose, amino acids, insulin, and glucagon after the ingestion of a "mixed meal" containing carbohydrate (50 g), protein (25 g), and fat (10 g) were examined. Nine subjects were tested during weeks 30-40 of gestation and again 6-8 wk postpartum. The "mixed meal" elicited greater and more prolonged increases in plasma glucose antepartum, whereas the increments in total serum amino acids were blunted at all time points. In the face of greater glycemic but lesser aminogenic stimulation, the integrated increase in plasma insulin was 60% greater antepartum than post partum, whereas the increment in glucagon was not significantly altered. Thus, integrated insulin/glucagon response was increased during antepartum studies. The insulin preponderance following alimentary challenge with mixed nutrients would suggest that the anabolism of ingested amino acids is "facilitated" during late human pregnancy.