Reduction of insulin resistance after correction of nonneoplastic ovarian virilization.

A 60-year-old woman with a progressive virilization for about 5 yr developed diabetes mellitus with elevated insulin levels (fasting insulinemia ranging 32.4-45.8 microU/ml). The marked increase of plasma testosterone (total 5.7-8.2 ng/ml; free 11.5 pg/ml) and other endocrine markers clearly indicated the ovarian origin of hyperandrogenism. Pelvic ultrasonography, computerized axial tomography, and direct examination of ovaries during laparotomy, showed no evidence of neoplasia. Microscopic examination and immunocytochemical investigations confirmed the diagnosis of hyperthecosis. After oophorectomy and regression of hyperandrogenism, fasting and postprandial blood glucose concentrations normalized in spite of persistently elevated levels of insulinemia (fasting values ranging 32.0-61.0 microU/ml). The present case suggests that pathological increase of testosterone can interfere with insulin-glucose balance impairing the peripheral sensitivity to insulin.