The effect of metformin treatment for 2 years without caloric restriction on endocrine and metabolic parameters in women with polycystic ovary syndrome

Abstract

Introduction: The aim of this study was to evaluate long-term changes in endocrine and metabolic parameters and body mass index in women with polycystic ovary syndrome (PCOS) who were treated with metformin over 2 years without caloric restriction.

Material and methods: Twenty-six obese women with PCOS were treated with metformin over 2 years without caloric restriction. Clinical, metabolic and endocrine parameters and the body mass index were measured and an oral glucose tolerance test was carried out to calculate insulin resistance indices at the beginning and at the follow-up after 2 years. The Homeostatic Model for Assessment of Insulin Resistance (HOMA-IR) was calculated.

Results: No significant changes in body mass index or HOMA-IR were observed. However, a significant decrease in fasting and 2-h insulin levels was observed. Women showed a significant increase in sex hormone-binding globulin (SHBG) levels, while total testosterone (TT) levels and the free androgen index decreased significantly. Furthermore a significant decrease in hirsutism was observed. There was a decrease in cholesterol and an increase in high-density lipoprotein.

Conclusions: Long-term treatment with metformin in women with PCOS appears to reduce androgen excess due to increased SHBG and decreased TT levels resulting in improvement of hirsutism as a clinical sign of androgen excess. Furthermore a significant decrease in fasting and 2-h insulin levels and slightly improved insulin resistance indices were observed.