SIRT1 and polycystic ovary syndrome: The decreased BMAL1 and P-AKT protein expression in the liver implied the association between circadian clock genes and the insulin-resistant state in PCOS (Fig. 2b), which was further supported by the disrupted rhythmic mRNA expression of Sirt1, Nampt, Glut4, and peroxisome proliferator activated receptor gamma (Pparg).