Antepartum and early postpartum predictors of type 2 diabetes development in women with gestational diabetes mellitus

Abstract

Objectives: This study aimed at identifying ante-partum and early post-partum (one year) clinical and metabolic characteristics capable of predicting the future development of type 2 diabetes in pregnant women of Mediterranea area affected by gestational diabetes mellitus (GDM).

Material and methods: Seventy GDM patients were evaluated: mean age during pregnancy, plasma glucose levels under OGTT (100 gr. glucose), fasting, 1-h post-prandial plasma glucose levels, HbA(1c) at the third trimester, gestational week of GDM diagnosis, insulin therapy, and weight gain were all taken into consideration. Some maternal risk factors such as pre-pregnancy BMI, and maternal and fetal outcome of index pregnancy were also assessed. One year after delivery in the same patients, BMI, fasting and 1-h post-prandial plasma glucose, plasma glucose and insulinemia under OGTT (75 gr. glucose) were measured. We focused our attention on women who presented type 2 diabetes 5 years after pregnancy or IGT and those who, one year after pregnancy, were normal.

Results: Five years after pregnancy 49 women were normal, 5 had developed type 1 diabetes and were not considered, 6 had developed IGT, and 10 type 2 diabetes. Analysis of variables during pregnancy showed that those variables predicting type 2 diabetes were pre-pregnancy BMI, gestational week of diagnosis, need for insulin therapy, obesity, and plasma glucose at 60' OGTT. Analysis of variables evaluated one year after pregnancy showed that BMI, fasting and post-prandial plasma glucose, plasma glucose at each point of the OGTT, and plasma insulin at 30' OGTT were predictive of the development of type 2 diabetes. Furthermore, age, post-partum fasting plasma glucose, and plasma glucose under OGTT post-partum were predictive of the development of IGT. Our data show for the first time that, also in a Caucasian Mediterranean population, markers of the future development of diabetes do exist, as reported in literature. They also stress the importance of correct identification of GDM patients, in order to screen those at greater risk of developing diabetes, for whom it is imperative to set up prevention programs.