The effect of continuous subcutaneous insulin infusion and conventional insulin regimes on 24-hour variations of blood glucose and intermediary metabolites in the third trimester of diabetic pregnancy.

Twenty-four hour metabolic profiles were performed in the third trimester of pregnancy in seven diabetic women; first when optimally controlled using conventional insulin regimes and subsequently when controlled with continuous subcutaneous insulin infusion. Seven non-diabetic women also studied. Mean +/- SD 24 h metabolite levels in the diabetics before and during continuous subcutaneous insulin infusion and in the controls were respectively: glucose-5.8 +/- 1.2;5.0 +/- 0.9;4.7 +/- 0.8 mmol/l; total ketone bodies -0.2 +/- 0.06; 0.15 +/- 0.05; 0.11 +/- 0.04 mmol/l; lactate - 0.90 +/- 0.33;0.90 +/- 0.24; 1.05 +/- 0.18 mmol/L; alanine - 0.29 +/- 0.06; 0.30 +/- 0.06; 0.31 +/- 0.03 mmol/l. Total ketone body levels were significantly elevated (p less than 0.05) on conventional therapy but not on continuous subcutaneous insulin infusion compared with controls. Variations in metabolites over 24 h, as measured by mean standard deviations, were increased for glucose (p less than 0.001) and for total ketone bodies (p less than 0.05) on the conventional regimes we employed compared with controls. On continuous subcutaneous insulin infusion variations of blood glucose were not affected whereas variations in total ketone bodies were no different from controls. The best possible maternal metabolic control is necessary for normal foetal development and continuous subcutaneous insulin infusion provides a method of achieving this.