Anti-Müllerian hormone as a driving force of polycystic ovary syndrome, independently from insulin resistance.

Research Question: Which clinical features, along with biological features, ultrasound features, or both, are the most strongly associated with either high or low anti-Müllerian hormone (AMH) levels in patients with polycystic ovary syndrome (PCOS)?

Design: A retrospective cross-sectional study conducted within a university-affiliated reproductive endocrinology unit in Lille, France. A total of 639 patients with PCOS according to the Rotterdam Criteria and 137 control women were included. A comparison of clinical, hormonal, metabolic and ultrasound data in patients with PCOS and controls belonging to the first (Q1) and fourth (Q4) quartiles of their respective AMH ranges (discriminant analysis) was conducted.

Results: In the PCOS group, patients in Q4 had higher LH levels and a more severe phenotype, but they were thinner and had lower levels of hyperinsulinaemia than patients in Q1. In the PCOS group, discriminant analysis yielded a highly significant model in which follicle number per ovary (FNPO) and serum LH were strongly and equally discriminating between Q4 and Q1 (R at 0.371 and 0.304, respectively, both P < 0.0001), whereas body mass index had less, although significant, effect (R = 0.075, P < 0.0001). In control women, discriminant analysis yielded a significant discriminant model, including only FNPO and age (R at 0.62 and 0.27, both P < 0.0001).

Conclusion: High serum AMH levels are associated with high serum LH levels and more severe features of PCOS. Conversely, the effect of hyperinsulinism may be greater in patients with lower serum AMH levels, suggesting independent effects of AMH and insulin on the phenotypic expression of PCOS.