Effects of combined metformin and cabergoline versus metformin alone on ovarian and hormonal activities in Iraqi patients with PCOS and hyperprolactinemia: a randomized clinical trial

Abstract

Polycystic ovary syndrome (PCOS) is one of the most prevalent metabolic diseases during female reproductive life, often associated with insulin resistance and hyperprolactinemia. The efficacy of metformin and cabergoline for managing PCOS remains debated in the literature. This three-arm interventional study in Iraq assessed the effects of these drugs on body mass index (BMI), hormonal balance, and uterine artery blood flow in 75 women with PCOS and hyperprolactinemia. Participants were randomized into three groups: metformin (500 mg twice daily), cabergoline (0.5 mg weekly), and a combination of both, with 25 patients in each group. Baseline and 90-day follow-up characteristics included BMI, serum hormonal levels, and ultrasound features. Metformin resulted in significant weight reduction (p=0.038); however, the addition of cabergoline caused a more significant reduction in body mass index (p=0.001). The combined treatment significantly lowered testosterone levels (p=0.008). In addition, this combination significantly reduced the level of LH (p=0.043) and increased the level of FSH (p=0.047). The results suggest that metformin and cabergoline when used together, act synergistically and safely to reduce BMI, testosterone, and LH levels while increasing FSH levels. Furthermore, this combination improved endometrial blood flow and ovulation in women with PCOS.