Rosiglitazone and ethinyl estradiol/cyproterone acetate as single and combined treatment of overweight women with polycystic ovary syndrome and insulin resistance

BACKGROUND: Few studies have evaluated insulin sensitizers in comparison/association with oral contraceptives (OC) in women with polycystic ovary syndrome (PCOS) with insulin resistance (IR). This study assessed the effects of a thiazolidinedione versus an anti-androgenic estrogen-progestin followed by their sequential combinations in overweight PCOS women. METHODS AND RESULTS: Twenty-eight candidates in whom elevated insulin was not normalized after 4 months of diet were randomly assigned to 6 months of rosiglitazone 4 mg/day or to ethinyl estradiol 35 μg/cyproterone acetate 2 mg (EE/CPA: 21/28 days cycle). Each group then received both medications for another 6 months. Rosiglitazone reduced insulin, IR indices [homeostasis model assessment (HOMA) and quantitative sensitivity check index (QUICKI)] and the insulin area under the curve in response to an oral glucose tolerance test (OGTT), but had limited effect on lipids, androgens and hirsutism. EE/CPA did not modify insulin and OGTT response but increased high-density lipoprotein cholesterol and triglycerides and decreased androgens and hirsutism. Similar changes occurred during combined treatments. End results were highly significant in combined groups without noticeable side-effects or changes in safety parameters. CONCLUSIONS: In obese PCOS women with high insulin not corrected by diet, the combination of rosiglitazone and EE/CPA may be used to achieve complementary beneficial effects on endocrine-metabolic anomalies and clinical symptoms.