Risk of early progression to prediabetes or diabetes in women with recent gestational dysglycaemia but normal glucose tolerance at 3-month postpartum.

OBJECTIVE: Both gestational diabetes mellitus (GDM) and milder glucose intolerance in pregnancy identify women who are at risk of developing type 2 diabetes. While some of these women will have prediabetes or diabetes in the early postpartum, most will have normal glucose tolerance (NGT), despite their future diabetic risk. In this context, we sought to evaluate the risk of early progression to dysglycaemia in women with NGT at 3-month postpartum and identify predictors thereof.
METHODS: Three hundred and twenty-five women with varying degrees of gestational dysglycaemia but NGT on oral glucose tolerance test (OGTT) at 3-month postpartum underwent repeat OGTT at 12-month postpartum.
RESULTS: By 12-month postpartum, 10% of the study population and 17.1% of those with recent GDM had progressed to dysglycaemia (primarily impaired glucose tolerance). At 3-month postpartum, compared to nonprogressors, the progressors had (i) higher BMI (P = 0.0023), LDL (P = 0.0017), triglycerides (P = 0.0002), leptin (P = 0.0021) and C-reactive protein (P = 0.043), and (ii) lower HDL (P = 0.0026) and adiponectin (P = 0.045). Notably, although all women had NGT at the time, each of the following glucose-related parameters from the OGTT at 3-month postpartum emerged as a significant independent predictor of progression on logistic regression analyses: area-under-the-glucose-curve (OR = 1.37, 95% CI: 1.13-1.65; P = 0.0012); sum of the glucose values (OR = 1.16, 95% CI: 1.05-1.29; P = 0.0042); and having a delayed blood glucose peak (occurring >30 min postload) (OR = 2.89, 95% CI: 1.29-6.45; P = 0.0097).
CONCLUSIONS: A normal OGTT at 3-month postpartum does not necessarily provide assurance of a low risk of progression to prediabetes. Glucose-related measures during this OGTT may identify those women at highest risk for early progression.