The objective of the present proposal is to compare the clinical, endocrine and metabolic effects of therapy with combination saxagliptin and metformin to saxagliptin and metformin monotherapy in women with PCOS and prediabetic hyperglycemia (IFG, IGT or IFG/IGT). Saxagliptin is an oral dipeptidyl peptidase IV (DPP-4) inhibitor whose mechanism of action is to prolong the duration of blood glucagon-like peptide (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) levels by inhibiting their degradation and thereby augmenting insulin secretion. This study will serve as a pilot investigation to open perspectives for future studies to explore the potential of combining anti-diabetic drugs with different mechanisms of action in in patients with PCOS and impaired glucose regulation (IGR), especially ones for whom standard treatment with metformin is less effective.