Glucose Absorption in Gestational Diabetes Mellitus During an Oral Glucose Tolerance Test

RESEARCH DESIGN AND METHODS-By undergoing 180-min oral glucose tolerance tests (OGTTs), pregnant women with GDM (GDM(preg); n = 15, BMI = 32 +/- 2 kg/m(2), aged 33 +/- 1 years) were compared with NGT women (NGT(preg); n = 7, BMI = 28 +/- 1 kg/m(2), aged 34 +/- 2 years), matching for major anthropometric characteristics (each P > 0.2). After delivery (6-7 months later), both groups were studied the same way. We computed and mathematically modeled gut glucose absorption from insulin-mediated glucose disappearance and endogenous glucose production (EGP). Whole-body insulin sensitivity was calculated using the Clamp-like Index.

OBJECTIVE-Women with gestational diabetes mellitus (GDM) show reduced insulin sensitivity and markedly elevated glucose excursions. After delivery, GDM mostly reverts to normal glucose tolerance (NGT), although leaving an increased risk of type 2 diabetes. Because gastrointestinal function changes during pregnancy causing vomiting, constipation, or reduced motility, we thought that gut glucose absorption in GDM or pregnancy might be altered to affect circulating glucose excursions.