SIRT1 and polycystic ovary syndrome: Hypercholesterolemia is also associated with oxidative stress, as studies have shown that hypercholesterolemia reduces liver sirtuin 1 (SIRT1) and induces hepatic oxidative stress. PCOS-induced rats model that was on a high-fat diet showed ovarian changes suggesting infertility is associated with dyslipidemia in PCOS [32].