New research to be presented at the Annual Meeting of The European Association for the Study of Diabetes (EASD) in Milan, Italy (Sept 28 – Oct 2) shows that, in women that develop type 2 diabetes (T2D), those who had gestational diabetes (GD) when pregnant are developing T2D on average almost 13 years earlier than those who did not. Those who had GD are also twice as likely to have more advanced disease requiring insulin treatment for their T2D within the first two years after their T2D diagnosis than those who did not have GD. The study is by Dr Maria Houborg Petersen, Steno Diabetes Center Odense (SDCO), Odense, Denmark, together with colleagues from SDCO and Steno Diabetes Center Aarhus, Denmark.
Extensive previous research has shown that women with previous GD (a form of diabetes that develops during pregnancy and then resolves) have a substantial long-term risk of developing T2D. Previous research has shown almost half of women who develop GD go on to develop T2D within 10 years. In this new research, the authors investigated the hypothesis that women with T2D and previous GD have a more severe T2D prognosis characterised by an earlier diabetes onset, higher prevalence of complications and more medication use compared to women with T2D without previous GD.
The study included patients in the Danish Centre for Strategic Research in Type 2 Diabetes (DD2)-cohort after their diabetes diagnosis – this cohort represents many, but not all, people newly diagnosed with T2D from all over Denmark. The study included all women in the DD2-cohort since 2010, who had previously been pregnant according to the Danish National Patient Register (n=2.865), and compared women with previous GD (n=173) to women without GD (n=2692) in terms of age at diabetes diagnosis, clinical traits and diabetes complications at study enrolment in the DD2-cohort.
The analysis showed women with previous GD were diagnosed with T2D more on average almost 13 years earlier than women without previous GD (median age 43.5 vs. 56.3 years), and around 40% of these women with previous GD were below 40 years of age at diabetes onset compared to just 6% of the women without previous GD.
Furthermore, at DD2 enrolment, women with previous GDM had a 2-fold higher prevalence of insulin treatment (10.4% vs. 5.2%) and lower fasting levels of serum C-peptide (median 1068 vs. 1195 pmol/l - indicating a more severe T2D with less insulin production) compared to women without previous GD.
Body mass index (BMI) and blood sugar control (HbA1c and fasting plasma glucose) were found to be similar between the groups, and there were no statistically significant differences in surrogate markers of insulin production and sensitivity. The prevalence of nephropathy, neuropathy, and cardiovascular disease were comparable in the two groups. While the researchers did find a statistically significant difference in the prevalence of diabetic retinopathy in women with or without previous GD, the very small numbers made it impossible to evaluate whether the difference is clinically relevant.
The authors conclude: "Women with a history of gestational diabetes in pregnancy are not only at substantially increased risk of developing type 2 diabetes later in life, but also tend to experience disease onset more than a decade earlier compared to women without prior gestational diabetes.
"In addition, these women more frequently require insulin therapy at the time of diabetes diagnosis. This pattern suggests a more severe form of type 2 diabetes and an elevated risk of subsequent complications. These findings underscore the importance of enhanced monitoring and follow-up strategies for women with a prior gestational diabetes diagnosis."
