Beta-cell dysfunction is the primary contributor to the early postpartum diabetes among Chinese women with history of gestational diabetes mellitus

Background Women with a history of gestational diabetes mellitus (GDM) are at higher risk of future development of diabetes. This study investigated the risk factors associated with early postpartum abnormal glucose regulation (AGR) among Chinese women with a history of GDM. Methods A total of 186 women with a history of GDM were screened for early postpartum AGR at 6-8 weeks after delivery. Those with AGR were given lifestyle intervention therapy and reevaluated in 6-12 months. The demographic, anthropometric, prenatal and delivery data were recorded. The plasma high-sensitivity C-reactive protein (HsCRP) and lipid concentration were measured, and insulin secretion were analyzed. Insulinogenic index Delta ins30'/Delta BG30', the homeostasis model assessment index (HOMA)-B, and HOMA-IR were calculated. Multiple regression analysis was performed to identify the risk factors. Results Of the GDM women 28.0% (52/186) had AGR at 6-8 weeks after delivery; 45.2% (17/40) of these AGR women reminded abnormal after 6-12 month lifestyle intervention. Compared to the women who reverted to normal, women with consistent AGR showed significantly lower fasting insulin concentration, lower Delta ins30'/Delta BG30' as well as lower HOMA-B. No significant differences in age, body mass index (BMI), waist circumference, blood pressure, lipid level, HsCRP and HOMA-IR were observed between the two groups. Pre-pregnancy BMI >= 25 kg/m(2), fasting glucose level >= 5.6 mmol/L and/or 75 g oral glucose tolerance test (OGTT) 2 hours glucose level >= 11.11 mmol/L during pregnancy were predictors for the AGR at 6-8 weeks after delivery. Delta ins30'/Delta BG30 <= 51.05 was a significant risk contributor to the consistent early postpartum AGR. Conclusion There is a high incidence of early postpartum AGR among Chinese woman with prior GDM. Beta-cell dysfunction, rather than insulin resistance or inflammation, is the predominant contributor to the early onset and consistent AGR after delivery.