The Influence of Obesity on Androstenedione to Testosterone Ratio in Women with Polycystic Ovary Syndrome and Hyperandrogenemia
October 2011
in “
Gynecological Endocrinology
”
obesity androstenedione testosterone polycystic ovary syndrome PCOS hyperandrogenemia androgen metabolism serum androstenedione testosterone/androstenedione ratio genetic factors insulin-stimulated overexpression KLF15 adipose tissue free androgen index FAI sex hormone-binding globulin SHBG insulin resistance IR visceral fat fat tissue
TLDR Obesity changes androgen levels in women with PCOS, leading to higher testosterone relative to androstenedione.
The study, which included 1,087 women with PCOS and 206 controls, found that obesity significantly altered androgen metabolism in women with PCOS and biochemical hyperandrogenemia by reducing serum androstenedione (A) levels and increasing the testosterone (T)/A ratio. This effect was not seen in PCOS women with clinical hyperandrogenemia or in normal ovulatory controls. The increased A-to-T conversion in obese PCOS women may be due to genetic factors, insulin-stimulated overexpression of KLF15, and the amount of adipose tissue. Obesity also affects androgen action by increasing the free androgen index (FAI) due to lower sex hormone-binding globulin (SHBG) and by contributing to insulin resistance (IR), which in turn stimulates A production. The study also suggested that visceral fat might play a role in promoting IR and hyperandrogenemia in PCOS.
