β-Cell function or insulin resistance was associated with the risk of type 2 diabetes among women with or without obesity and a history of gestational diabetes

INTRODUCTION: To evaluate the single association of postpartum β-cell dysfunction and insulin resistance (IR), as well as different combinations of postpartum β-cell dysfunction, IR, obesity, and a history of gestational diabetes mellitus (GDM) with postpartum type 2 diabetes risk. RESEARCH DESIGN AND METHODS: The study included 1263 women with prior GDM and 705 women without GDM. Homeostatic model assessment was used to estimate homeostatic model assessment of β-cell secretory function (HOMA-%β) and homeostatic model assessment of insulin resistance (HOMA-IR). RESULTS: Multivariable-adjusted ORs of diabetes across quartiles of HOMA-%β and HOMA-IR were 1.00, 1.46, 2.15, and 6.25 (p(trend) <0.001), and 1.00, 2.11, 5.59, and 9.36 (p(trend) <0.001), respectively. Women with IR only had the same diabetes risk as women with β-cell dysfunction only. Obesity, together with IR or β-cell dysfunction, had a stronger effect on diabetes risk. This stronger effect was also found for a history of GDM with IR or β-cell dysfunction. Women with three risk factors, including obesity, a history of GDM and β-cell dysfunction/IR, showed the highest ORs of diabetes. CONCLUSIONS: β-cell dysfunction or IR was significantly associated with postpartum diabetes. IR and β-cell dysfunction, together with obesity and a history of GDM, had the highest ORs of postpartum diabetes risk.