Postpartum Microalbuminuria After Gestational Diabetes: The Impact of Current Glucose Tolerance Status

Context: It has been reported that women with a history of gestational diabetes mellitus (GDM) have an increased risk of microalbuminuria compared with that of their peers. Because previous GDM predicts an increased risk of prediabetes, which itself is associated with microalbuminuria, we hypothesized that current glucose intolerance may confound any association between GDM and microalbuminuria. Objective: The purpose of this study was to evaluate the relative impact of gestational and current dysglycemia on postpartum microalbuminuria in a cohort of women reflecting the full spectrum of gestational glucose tolerance from normal to mildly abnormal to GDM. Design/Setting/Participants: In this prospective observational cohort study, 320 women underwent a glucose challenge test (GCT) and an oral glucose tolerance test (OGTT) in pregnancy, which identified 100 women with GDM, 58 with gestational impaired glucose tolerance, 90 with an abnormal GCT but a normal OGTT, and 72 with a normal GCT and OGTT. At 3 years postpartum, they underwent measurement of urine microalbumin and a repeat OGTT that identified 63 women with glucose intolerance (prediabetes/diabetes). Results: The postpartum urine microalbumin to creatinine ratio did not differ among the 4 gestational glucose tolerance groups (P = .23). Furthermore, on logistic regression analysis, GDM did not independently predict an elevated urine microalbumin to creatinine ratio of >= 1.5 g/mol of creatinine (odds ratio, 0.43; 95% confidence interval, 0.17-1.11), after adjustment for age, ethnicity, family history of diabetes, body mass index, blood pressure, estimated glomerular filtration rate, and current glucose intolerance. In contrast, current glucose intolerance independently predicted a urine microalbumin to creatinine ratio of >= 1.5 (odds ratio, 3.4; 95% confidence interval, 1.4-8.2, P = .005). Conclusion: Current glucose intolerance, rather than previous GDM, may be associated with an increased risk of microalbuminuria in the early postpartum years.