Subclinical hypothyroidism: a determinant of polycystic ovary syndrome.

The present study was an endeavor to explore whether and how hypothyroidism plays a role in the etiology of polycystic ovarian syndrome (PCOS). A composite picture of the hormone profile was assessed in different groups of subjects (control women and hypothyroid women with or without PCOS). Comparative analysis of the results suggests that hypothyroidism is invariably followed by a lowering of sex hormone binding globulin and an increment in the free testosterone level, but further metabolism of testosterone (T) may or may not be directed towards an overproduction of estriol (E3). The factors that dictate the route of T metabolism, and the way by which E3 acts to rescue the ovaries from the development of PCOS under the hypothyroid state are discussed.