Type 2 diabetes significant risk for women with gestational diabetes
medwireNews: Women with gestational diabetes mellitus (GDM) should be tested for glycemic parameters at 2 months postpartum and annually thereafter, suggest findings from an Asian study.
In a prospective study of GDM women monitored for the development of Type 2 diabetes, a significant proportion developed the condition at just 2 months postpartum (early converters), while many more went on to develop the condition at a later period (late converters).
"This study is one of the largest prospective cohort studies in Asians to investigate the incidence and risk factors of T2DM [Type 2 diabetes mellitus] in GDM women," say Kyong Soo Park (Seoul National University Hospital, Korea) and colleagues.
It has previously been shown that women with GDM are at an increased risk for developing Type 2 diabetes, notes the team. However, "there are ethnic differences in the risk of developing T2DM after GDM pregnancy." In addition, although risk factors for diabetes after GDM have been established, it is not clear whether these risk factors differ between early and late converters.
The researchers report that of 843 women with GDM enrolled in their study, 105 (12.5%) had Type 2 diabetes at 2 months postpartum, after which the number of individuals with the condition steadily increased at a rate of 6.8% per year until 10 years of follow up.
Among the 738 women without diabetes at 2 months postpartum, 370 attended follow-up visits for more than 1 year and 88 (23.8%) of these developed diabetes during a median follow-up period of 49 months.
As reported in the Journal of Clinical Endocrinology and Metabolism, the team performed multivariate analysis to compare early and late converters with women who never developed the condition.
Independent risk factors for the early development of Type 2 diabetes were increased prepregnancy body mass index (BMI), elevated glucose level during an antepartum oral glucose tolerance test (OGTT), decreased fasting insulin level, and decreased insulin sensitivity/insulin resistance disposition index.
For late converters, risk factors were prepregnancy BMI and hyperglycemia during antepartum OGTT.
When early and late converters were compared directly, they had similar degrees of obesity but significantly different degrees of ß-cell function, with more severe defects in ß-cell function observed among early converters. This group was also significantly more likely to require insulin treatment during pregnancy.
"This difference in ß-cell function might have resulted in conversion to T2DM at different times," suggest Park et al, who say that further studies should be conducted to determine the relative importance of obesity and ß-cell dysfunction in the development of diabetes after GDM pregnancy.
In addition, they conclude that "further investigations of genetic and environmental risk factors should develop useful prediction models of T2DM in previously GDM women."
By Sally Robertson, medwireNews Reporter