EFFECT OF HYPERINSULINEMIA ON THE DEVELOPMENT OF BLOOD-COAGULATION INTHE LAMB FETUS

Infants of diabetic mothers have an increased risk for thrombosis. The etiology of their hypercoagulable state is unknown. To examine the ef fects of hyperinsulinemia on the development of coagulation during fet al life, 10 sets of chronically catheterized fetal lambs were studied. One twin from each pair of 120-d gestation lamb fetuses was infused w ith insulin at a rate of 2.5 U/h for 48 h, whereas its twin sibling wa s infused with an equal volume (20 mt) of dextrose 5% in water. Change s in coagulation factor activities were measured before and after the infusions, and differences were analyzed by paired t tests. There was a significant decrease in protein C after insulin treatment in the ins ulin-treated twins. There were relative increases in fibrinogen factor s V, VII, and XI when the insulin-treated group was compared with the controls. The changes are consistent with an increased risk of thrombo sis and may explain, in part, the higher incidence of thrombosis in in fants of diabetic mothers.