Does insulin resistance affect ovaries?
It affects 70-95% of obese PCOS patients and 30-75% of lean PCOS patients (2,3). High insulin levels are not just a symptom of PCOS; they are also a primary cause of the condition (1,4,5,6). High insulin levels can impede ovulation and cause the ovaries to produce too much testosterone.
Insulin stimulates steroidogenesis by granulosa cells in normal and polycystic ovaries and interacts with gonadotropins in an additive or synergistic manner, as in the case of LH.
How does insulin affect ovulation?
Insulin plays a critical function in ovarian steroidogenesis and thus in ovulation. Granulosa and theca cells are affected by hyperinsulinemia. Because of hyperinsulinemia, luteinizing hormone generates an early response on the granulosa cells of tiny follicles and causes theca cells to differentiate prematurely.