[Breakfast tolerance test: application to the detection of gestational diabetes]

There is general agreement that diagnosis of diabetes mellitus in pregnancy is requisite but the means of achieving it are still under discussion. The plasma glucose, insulin and C peptide responses to an oral glucose tolerance test were compared with the intravenous glucose tolerance test and a standardized breakfast tolerance test in 26 pregnant women, in order to define a simple diagnostic criterion for gestational glucose intolerance. The results of the oral glucose tolerance test distinguished between a group of 19 normal women and a group of 7 diabetic women with abnormal glucose tolerance tests. The breakfast tolerance test used (84 g carbohydrates, 22,6 g protein, 9,4 g fat, 690 calories) was followed by blood glucose modifications very similar to those observed with the oral glucose tolerance test, but the insulin response was significantly greater. The consistency between the breakfast tolerance and intravenous glucose tolerance tests was confirmed by the existence of correlations between the glucose area of the breakfast tolerance test and the coefficient K in the two groups studied. Our results suggest that the breakfast tolerance test could be as sensitive as the oral glucose tolerance test for detecting glucose intolerance; the most discriminative glycemic value appeared to be that at the 180 th minute, usually under 1 g/l in the normal pregnant women. This test could be proposed as an easy and economic method for diagnosing gestational diabetes. These preliminary results require confirmation by a study in a larger population.