Weight Gain and Progression to Type 2 Diabetes in Women With a History of Gestational Diabetes Mellitus

Context: The effect of weight gain on the development of type 2 diabetes after gestational diabetes mellitus (GDM) is not fully understood in Asian women who have a relatively low body mass index (BMI). Objective: We investigated the effect of postpartum longitudinal BMI change on the development of diabetes in Korean women with a history of GDM. Design and Setting: The study included a hospital-based, multicenter, prospective cohort with median follow-up of 4.0 years. Participants: A total of 418 women with previous GDM or gestational impaired glucose tolerance were recruited and underwent an oral glucose tolerance test at 6 weeks postpartum and annually thereafter. Main Outcome Measure: The risk of diabetes was analyzed according to the tertiles of BMI change. Changes in BMI were calculated between the initial postpartum visit and the last follow-up or at the onset of diabetes. Results:The BMI change in each tertile was -1.8 +/- 1.1, -0.2 +/- 0.3, and 1.6 +/- 1.2 kg/m(2), respectively. We observed an increased risk of incident diabetes as the tertile of BMI change increased (8.6%, 12.6%, and 16.9%, P =.039). Postpartum BMI change was an independent predictor of diabetes in a multivariate Cox analysis (hazard ratio 1.27, 95% confidence interval 1.04-1.56, P=.021), even after adjusting for BMI at the last follow-up. In the highest tertile group, there was a significant deterioration in cardiovascular risk factors including blood pressure, lipid profile, and insulin sensitivity. Conclusions: Postpartum increase in BMI is significantly associated with a risk of diabetes and deterioration of metabolic phenotypes in Korean GDM women.