Women with gestational diabetes at increased risk for type 1 diabetes: Study
Finland: Women with gestational diabetes are more likely to develop type 1 diabetes (T1D) in the decade following delivery versus pregnant women without gestational diabetes, finds a recent study.
The findings of the study were presented at the European Congress of Endocrinology (virtual meeting) held from May 22-26, 2021.
It is already known that women with gestational diabetes are at high risk for developing type 2 diabetes (T2D) later in life but the study results presented by Kaisu Luiro-Helve, University of Helsinki and Helsinki University Hospital, Finland, showed that risk for T1D is also increased.
Luiro-Helve and colleagues previously conducted a prospective, 6-year cohort study showing an association of islet cell autoantibodies (ICA) and glutamic acid decarboxylase autoantibodies (GADA), gestational diabetes diagnosis before age 30 years, and the need for insulin treatment during pregnancy as high-risk factors of progression to type 1 diabetes.
In the prospective cohort study, the researchers analyzed data from 391 women with gestational diabetes and 391 age-, parity- and delivery date-matched controls who delivered from 1984 through 1994 and underwent autoantibody testing during the first trimester of pregnancy.
Researchers assessed levels of four autoantibodies associated with type 1 diabetes: ICA, GADA, insulin autoantibodies (IAA) and insulinoma-associated antigen-2 autoantibodies (IA-2A). Women completed a follow-up questionnaire assessing later type 1 or type 2 diabetes diagnosis in 2012-2013. The mean follow-up time was 23 years.
Key findings of the study include:
- Researchers observed single autoantibody positivity in 12% of the gestational diabetes cohort and in 2.3% of the control cohort.
- In the gestational diabetes cohort, 2.6% tested positive for two autoantibodies and 2.3% tested positive for three autoantibodies, whereas only one woman in the control cohort had two autoantibodies detected.
- ICA positivity was found in 12.5% of cases, followed by GADA (6%), IA-2A (4.9%) and IAA (1.2%). In the control cohort, GADA positivity was found in 1.4% of cases, followed by IA-2A (0.8%), IAA (0.6%) and ICA (0.3%).
- All women with three positive autoantibodies developed type 1 diabetes within 7 years from pregnancy with gestational diabetes.
- Development of type 2 diabetes and gestational diabetes occurred independent of autoantibody positivity.
Luiro-Helve said clinicians should look more closely at women with a gestational diabetes diagnosis who require insulin therapy, in which diet or metformin is not enough, or at women with a gestational diabetes diagnosis in the setting of normal BMI.
"If you are not the typical gestational diabetes candidate, but you have it, that may warrant more screening," Luiro-Helve said. "Type 1 diabetes is not just a disease of the young. Type 1 usually occurs within 10 years of gestational diabetes, and that is the time when we need to stay alert and perhaps conduct another oral glucose tolerance test. Do not forget about these women after delivery."
