Endocrine Abstracts

Introduction: Anti-Müllerian hormone (AMH) has an inhibitory role during folliculogenesis, which may contribute to anovulation in polycistic ovary syndrome (PCOS). AMH level has been shown to be a predictor of reproductive response to weight loss and clomiphene citrate in women with PCOS. The aim of this study was to evaluate the role of AMH as a predictor of improvements in menstrual cyclicity and ovulation induction by metformin in lean women with PCOS.

Design: Twenty-one lean unovulatory women with PCOS (age 24.2±3.2 year, body mass index (BMI) 21.4±2.3 kg/m²) received metformin 1700 mg/day during 6 months. We estimated ovulation induction (by ultrasound scanning), change in menstrual cycle, anthropometric measurements, endocrine parameters and insulin sensitivity.

Results: Twenty women completed the trial. 11 of them (55%) responded to the intervention by improvement in menstrual cyclicity (responders, 9 of which recommenced ovulation). There was no difference between responders and nonresponders in age, BMI, waist circumference, basal levels of gonadothropins, androgens, fasting insulin and homeostasis model assessment. Compared to nonresponders, responders had lower AMH levels at baseline (7.2±3.1 vs 12.7±2.6 ng/ml; P=0.021). Using ROC-curves we calculated that the value of AMH <8 ng/ml can predict improvement of menses (sensitivity 72.7%, specificity 99%) and ovulation induction (sensitivity 66.7%, specificity 81.8%) by metformin in lean women with PCOS. Likewise, the mean follicle number per ovary was lower in responders than in nonresponders (11.0±1.5 vs 15.7±5.9, P=0.011). It was significantly related to the serum AMH levels (r=0.579, P=0.006).

Conclusions: AMH measurement can be useful in the prediction of ovarian response to metformin therapy in lean patients with PCOS.