Endocrine Abstracts

Objective

The aim of the study was to compare the effect of metformin, orlistat and pioglitazone on insulin resistance in patients with polycystic ovarian syndrome.

Methods

30 overweight PCOS women were recruited using the Rotterdam criteria (mean age (±S.E.M.) 26(±1.5)yrs and body mass index 35.9(±1.3) kg/m²). Fasting blood was collected at the same time each day on 10 consecutive occasions at 4-day intervals before and 3 months after treatment with metformin (500 mg three times daily), orlistat (120 mg three times daily) or pioglitazone (45 mg once daily). The mean HOMA-IR ((insulin×glucose)/22.5) was calculated from the pre and post treatment samples. All subjects gave their informed written consent prior to entering the study and local ethical committee approval had been obtained.

Results

The results are expressed as percentage change from baseline (mean±S.E.M). Metformin, orlistat and pioglitazone all resulted in a reduction in HOMA-IR after 3 months with percentage change of −14.6%±10.2, −7.4%±16.4 and −1.3%±12.5 respectively (P=0.36). Patients on metformin and orlistat had a reduction in body mass index (BMI) of −3.4%±1.0 and −5.0%±1.0 respecively (P=0.56) whereas those on pioglitazone increased BMI of 3.4%±1.3.

Conclusions

We found no difference in the mean of HOMA-IR before and after treatment with all three medications suggesting that orlistat, pioglitazone and metformin are equally effective in treatment of patients with PCOS. However, pioglitazone reduces insulin resistance at the expense of an increased BMI.