Metformin improves polycystic ovary syndrome symptoms irrespective of pre-treatment insulin resistance

In a study from 2007 involving 188 patients with polycystic ovary syndrome (PCOS), metformin treatment over 6 months was found to significantly improve insulin resistance (IR), hyperandrogenemia, anovulation, and acne in PCOS patients, regardless of their pre-treatment insulin resistance or body mass index (BMI). The study divided the PCOS patients into three groups based on BMI (lean, overweight, and obese) and compared them with 102 healthy controls. While only obese PCOS patients showed differences in fasting insulin and HOMA-IR compared to controls, metformin therapy improved all outcome parameters except fasting glucose levels across all BMI groups. Notably, in lean PCOS patients without pre-treatment IR, metformin significantly improved HOMA-IR, fasting insulin levels, testosterone levels, anovulation rate, and acne. The study concluded that metformin is beneficial for PCOS symptoms across different weight categories and levels of insulin resistance.