GIP and polycystic ovary syndrome: BMI: body mass index, CPA/EE: cyproterone acetate/ethinyl estradiol, CRP: C-reactive protein, FAI: free androgen index, FSH: follicle-stimulating hormone, GIP: gastric inhibitory polypeptide, GLP-1: glucagon-like peptide-1, HbA1c: hemoglobin A1c, HDL: high-density lipoprotein, HOMA-IR: Homeostatic Model Assessment for Insulin Resistance, ISR: insulin secretion rate, LDL: low-density lipoprotein, LH: luteinizing hormone, MET: metformin, PCOS: polycystic ovarian syndrome