Pathologic subtypes in Japanese women with gestational diabetes

Abstract

It has been suggested that two pathologic conditions, increased insulin resistance (IR) and impaired insulin secretion (IIS), are involved in the development of gestational diabetes mellitus (GDM). We attempted to classify women with GDM according to those pathologic subtypes and examine the association between the subtypes and perinatal and postpartum risk. We conducted a retrospective study of singleton women with GDM whose insulin were measured at a 75-g oral glucose tolerance test (OGTT) both during pregnancy and early postpartum. Homeostasis model assessment (HOMA) - IR and insulinogenic index (IGI) were used as indices of IR and insulin secretion, respectively. We defined IR as HOMA-IR ≥75%tile values of women with a normal OGTT result, and IIS as IGI < 0.4. The pathologic subtypes were classified into IR, IIS, mixed, and normal types. We examined the association between those subtypes and intensive insulin therapy (IIT) during pregnancy defined as requiring insulin ≥20 U/day and early postpartum abnormal glucose tolerance (AGT). 253 subjects were classified as follows: IR, 34%; IIS, 25%; mixed, 4%; normal, 37% during pregnancy. Compared with the normal subtype, women with the IR, IIS and mixed types were significantly associated with the IIT, while the incidence of postpartum AGT did not differ significantly (Table). 61% and 75% of women with the IR/mixed and IIS type during pregnancy persisted the same subtypes in the postpartum, respectively. Women with GDM with the pathologic subtypes were associated with the risk of insulin therapy. More than 60% of those women persisted the same abnormal subtypes in the early postpartum.