Comparison of glycemic control and β-cell function in new onset T2DM patients with PCOS of metformin and saxagliptin monotherapy or combination treatment

BACKGROUND Impaired insulin activity in women with polycystic ovary syndrome might differ from that seen in type 2 diabetes mellitus without polycystic ovary syndrome. This study was designed to compare the effects of treatment with metformin, saxagliptin, and their combination in newly diagnosed women with type 2 diabetes mellitus and polycystic ovary syndrome in China. METHODS A total of 75 newly diagnosed patients from Shanghai, China with type 2 diabetes mellitus and polycystic ovary syndrome were included in this randomized, parallel, open-label study. All patients received treatment for 24 weeks with metformin, saxagliptin, or their combination. Patients were allocated to one of three treatment groups by a computer-generated code that facilitated equal patient distribution of 25 patients per group. The primary outcome was a change in glycemic control and β-cell function. RESULTS A total of 63 patients completed the study (n = 21, for each group). The reduction in hemoglobin A1c was significant in the combination group, compared to the monotherapy groups (saxagliptin vs. combination treatment vs. metformin: - 1.1 vs. -1.3 vs. -1.1%, P = 0.016), whereas it was comparable between the metformin and saxagliptin groups (P > 0.05). Saxagliptin, metformin, and the combination treatment significantly reduced the homeostasis model assessment- insulin resistance index and increased the deposition index (P < 0.01 for all). However, no significant change was observed in the homeostasis model assessment- β-cell function among the metformin and combination groups, and no significant changes were observed in the insulinogenic index among all three groups (P > 0.05 for all). In addition, saxagliptin and metformin treatments significantly reduced body mass index and high-sensitivity C-reactive protein levels (P < 0.01 for both). CONCLUSIONS Saxagliptin and metformin were comparably effective in regulating weight loss, glycemic control, and β-cell function, improving lipid profiles, and reducing inflammation in newly diagnosed type 2 diabetes mellitus patients with polycystic ovary syndrome. TRIAL REGISTRATION ChiCTR-IPR-17011120 (retrospectively registered on 2017-04-12).