Compared to the NGT group, the two GDM groups exhibited significantly higher fasting and post-load glucose concentrations, which, along with the plasma HbA1c level, positively correlated with leukocyte SIRT1 expression; this implies a linkage between leukocyte SIRT1 mRNA up-regulation and both the early and late phase of hyperglycemia. Here, SIRT1 is linked to gestational diabetes.