With serum RBP4, serum CysC, and nesfatin-1 as dependent variables, univariate correlation analysis showed that serum RBP4, serum CysC, and nesfatin-1 levels were positively correlated with FPG and HbA1c levels and HOMA-IR, and negatively correlated with FINS in women with gestational diabetes mellitus (P < 0.05) (Table 3). Here, RBP4 is linked to gestational diabetes.