The Incidence of Glutamic Acid Decarboxylase Autoantibodies and its Association With Clinical Features in Pregnant Women With Gestational Diabetes Mellitus

Introduction: The association between the incidence of glutamic acid decarboxylase antibodies(GADAs) and risk of diabetes in pregnant women is controversial. Here, our aim was to investigate the incidence and clinical relevance of GADA and its association with development of postdelivery diabetes in women with gestational diabetes mellitus (GDM).Methods: This cohort study was conducted in Torbat–e Heydarieh (Khorasan Razavi, Iran) from October 2015 to March 2017. A total of 147 pregnant women with GDM were included in case group. The control group consisted of 147 healthy controls. A GAD diagnostic kit (Diametra Co.,Italy) was used for diagnosis of GADA. The history of insulin therapy and the development of diabetes one year after delivery were investigated.Results: Of 147 pregnant women with GDM, 9 (6.1%) had GADA in their sera. 14.3% (21 out of 147) of women with GDM had history of insulin therapy. 33.3% (7 of 21) of women who had received insulin developed diabetes one year after delivery. Type 1 and type 2 diabetes were observed in, respectively, 1 (0.7%) and 7 (4.8%) of women with GDM at one year after delivery.At one year after delivery, no women in GADA negative women was diagnosed with type 1 diabetes. However, type 2 diabetes was observed in 2.9% of GADA negative pregnant women.Type 1 and type 2 diabetes were also noticed in, respectively, 11.1% and 33.3% of GADA positive mothers at one year after delivery.Conclusion: The prevalence of GADA was 6.1% in diabetic pregnant women. The GADA positivity and history of insulin therapy during pregnancy were significant risk factors for diabetes at one year after delivery. In addition, development of type 1 diabetes was higher in GADA positive pregnant women with GDM than GADA negative women.