Circulating 1,5-anhydroglucitol levels combined with pre-pregnancy BMI is a simple predictive marker of future glucose intolerance in women with gestational diabetes

In women with gestational diabetes (GDM), 1,5-Anhydroglucitol (1,5-AG) levels are lower compared to controls. However, data on 1,5-AG changes in the postpartum and its associations with indices of insulin secretion or resistance in the perinatal period are lacking. This prospective study assessed the trajectory of 1,5-AG, 1,5-AG/HOMA-IR and 1,5-AG/BMI during pregnancy up to 1-year postpartum, their association with indices of insulin secretion/resistance and whether these indices can predict glucose intolerance (prediabetes and diabetes) at 1-year postpartum in women with GDM. We included 211 women with GDM and assessed 1,5-AG levels at 28–32 weeks of gestational age, at 6–8 weeks and at 1-year postpartum. In the context of changing body mass and insulin resistance, we also investigated 1,5-AG/BMI and 1,5-AG/HOMA-IR to adjust for prevailing BMI and HOMA-IR. Circulating 1,5-AG levels and 1,5-AG/BMI were stable between pregnancy and 6–8 weeks postpartum but increased at 1-year postpartum (p < 0.001). 1,5-AG/HOMA-IR increased between pregnancy and the early postpartum and stabilized at 1-year postpartum (p < 0.001). In the perinatal period, 1,5-AG/HOMA-IR was related to a higher insulin-resistance adjusted insulin secretion index (ISSI-2), lower BMI and higher MATSUDA (all p ≤ 0.001). 1,5-AG/pre-pregnancy BMI during pregnancy and 1,5-AG/HOMA-IR at 6–8 weeks postpartum (both p ≤ 0.024) predicted a lower risk of glucose intolerance at 1-year postpartum, the latter remained significant after adjusting for HbA1c. These results suggest that 1,5-AG/HOMA-IR and 1,5-AG/pre-pregnancy BMI change in the perinatal period. They could provide useful information and may serve as markers of future glucose intolerance, and for early risk stratification in women after GDM.