Carbohydrate metabolism in pre-eclampsia.

Intravenous glucose tolerance tests were performed on 30 primigravidae with pre-eclampsia and 15 normal primigravidae in late pregnancy. The groups were matched for age, height and weight and had no stigmata of potential diabetes. Plasma glucose, plasma immunoreactive insulin and plasma placental lactogen (HPL) levels were measured before (fasting) and at timed intervals after the glucose challenge; the glucose response was expressed as the increment index. The patients with severe pre-eclampsia had significantly lower fasting plasma glucose levels than those with mild pre-eclampsia and normal pregnancies. The mean increment index in both the severe and mild pre-eclamptic groups was significantly lower than that of the normal pregnant group. Fasting HPL levels were significantly lower in patients with severe pre-eclampsia than in those who had mild pre-eclampsia or a normal pregnancy. Both the fasting plasma insulin and insulin response following glucose injection were lower in patients with severe pre-eclampsia than in those with mild pre-eclampsia or a normal pregnancy. The differences however were not statistically significant. The results of this study suggest that carbohydrate metabolism in severe pre-eclampsia is altered to an extent similar to that in patients with chemical gestational diabetes, and this alteration may be due to maternal beta-cell anoxia caused by the vascular changes in pre-eclampsia.