Characteristics of polycystic ovary syndrome with and without insulin resistance and the role of insulin sensitizing drug (metformin) in its management

Objectives: To define the clinical and biochemical characteristics in polycystic ovary syndrome (PCOS) patients with and without insulin resistance (IR); and to evaluate the role of metformin as an insulin sensitizing drug in infertile IR PCOS patients with regard to both reproductive and metabolic functions. Materials and Methods: Fifty five PCOS women with an initial complaint of infertility. Other presentations include obesity, hirsutism and acanthosis nigricans (AN). According to fasting glucose/insulin (G/I) ratio, the patients were classified into two groups; group I: IR PCOS and group II: non-IR PCOS. The patients in both groups I & II were given Clomiphene citrate (CC) for 5 days from 2nd day of the period for six months. Group I was subdivided according to treatment protocol into: group Ia who received metformin daily in addition to (CC) and group Ib who received CC only. Body mass index (BMI), Ferriman-Gallwey score and (G/I) were calculated. Fasting glucose (G), fasting insulin (I), follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), progesterone (P), total cholesterol (TC) and triglyceride (TG) were also measured. The clinical and biochemical parameters were assessed initially and at end of treatment. Results: Thirty four of the 55 PCOS patients had IR (62%). Obesity, hirsutism and AN were common association in group I. LH, LH/FSH and T were significantly lower in group I compared with group II (P <0.05). Ovulation rate was improved in group Ia and became similar to group II while group Ib was more resistant to ovulation induction with CC. Pregnancy rates were also higher in group Ia and group II Vs group Ib but not to a significant level. After 6 months of treatment with metformin + CC, there was a significant improvement in ovulation rate, LH, LH/FSH, T, FI, BMI, TG and TC levels in group Ia compared with pre-treatment levels (P >0.05). All post-treatment parameters in group Ia were also significantly improved compared with those in group Ib (P >0.05). Conclusion: IR-PCOS patients are more likely to be obese, hirsute and have AN. They are also more resistant to ovulation induction with CC. They tend to have lower LH, LH/FSH and T levels. Metformin improves the response to ovulation induction with CC as well as the pregnancy rates in IR-PCOS. It also appears that metformin may be of help in improving the other metabolic parameters related to IR syndrome so it may retard or prevent the long-term complications of this syndrome