of Pioglitazone and Metformin on Insulin Resistance Reduction in Polycystic Ovary Syndrome: A Comparative Study

Polycystic ovary syndrome (PCOS) is among the most common endocrine disorders in women of reproductive age and affects 7% of this population. PCOS is identified as a reproductive disorder characterized by an ovulation, hyperandrogenism and insulin resistance. PCOS increases the risk for type 2 diabetes mellitus and metabolic syndrome, a constellation of cardiovascular risk factors associated with insulin resistance. The aim of our study was to investigate and compare insulin resistance reduction and chemical changes during the application of insulin sensitizers from two different groups (metformin and pioglitazone). This randomized clinical trial lasted for 3 months and was conducted in Avicenna Hospital, Qazvin, Iran. Overall, 56 women with PCOS were randomly divided into two groups. Group 1 received 500 mg metformin three times daily and group 2 was treated with pioglitazone 30 mg per day. Serum levels of insulin, fasting blood sugar (FBS), and lipid metabolism parameters including triglyceride (TG), cholesterol (Chol), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) were measured before the treatment and in the 3rd month. Homeostasis model assessment of insulin resistance (HOMA-IR) was used. Body mass index (BMI) was also calculated at baseline and at the end of therapy. Before the treatment, the two groups matched for age, weight, and BMI (P > 0.05). Before the treatment, there were no statistically significant differences in FBS, HDL, LDL, TG, Chol and serum levels of insulin between the two groups. Three months after treatment, mean serum levels of FBS, TG, Chol, LDL and insulin decreased significantly in both groups. Moreover, the treatment significantly increased HDL levels in both groups (P < 0.01). In metformin group, mean values of BMI before and after treatment were 26.1 and 25.5 (P < 0.05). The corresponding values in pioglitazone group were 25.9 and 25.2 (P > 0.05). Our findings showed that in women with PCOS, treatment with metformin and pioglitazone for 3 months resulted in similar beneficial effects on laboratory parameters of insulin sensitization. However, there is no evidence that pioglitazone improves BMI when compared to metformin. Further research is needed to investigate whether treatment with insulin sensitizers in women with PCOS can also reduce cardiovascular risk factors.