Obesity and oligomenorrhea are associated with hyperandrogenism independent of hirsutism

Obesity, oligomenorrhea, and hirsutism are frequently associated with high plasma androgen levels and/or low testosterone-binding globulin (TEBG) levels. Studied have been undertaken to determine the extent to which each of these clinical features may be related to this hormonal profile. Indexes of plasma free (unbound) androgen levels were focused upon because this fraction appears to be the biologically active portion of the plasma androgens. The hormonal profile was normal in women with either obesity or oligomenorrhea alone and abnormal in those with severe hirsutism alone. On striking new finding was that subjects with the combination of obesity and oligomenorrhea had elevated plasma total and free androgens and depressed TEBG even in the absence of hirsutism. Furthermore, the androgen levels were higher in obese oligomenorrheic women with mild hirsutism than in severely hirsute women who were not obese. Plasma estradiol concentrations were normal in these obese women. A simple explanation for elevated free plasma androgen levels in obese women who were oligomenorrheic yet had little if any hirsutism is not possible. The data are compatible with the concept that obesity is a variably expressed manifestation of slightly elevated plasma free androgen levels or that obesity is an incidental finding which somehow blunts the effect of high androgen levels on hair follicles. Regardless of the explanation, oligomenorrheic obese women must be suspected of having high androgen production even in the absence of hirsutism.