Age-specific reference values improve the diagnostic performance of AMH in polycystic ovary syndrome

Background The increased secretion of anti-Mullerian hormone (AMH) by the growing follicles has been supposed as a determinative feature of polycystic ovary syndrome (PCOS). The diagnostic performance of AMH in PCOS is superior compared to the free androgen index (FAI) and luteinizing hormone (LH)/follicle-stimulating hormone (FSH) quotient. We established age-dependent reference ranges to further improve the diagnostic performance of AMH. Methods In a cross-sectional study, in samples of 4712 reproductive age patients, ranging from 14 to 50 years, BMI, AMH and other reproductive hormones were determined by immunoassay or tandem mass spectrometry (LC-MS/MS) to calculate age-specific reference ranges and the diagnostic performance. Results Age-specific diagnostic performances for Elecsys(R) AMH, FAI and LH/FSH ratio were established in the reference group. No significant difference in BMI was found between the groups. AMH values were significantly negatively correlated with age (r = -0.628, p < 0.001) in patients with normal ovarian function, but there was no correlation between age and AMH levels in PCOS patients (r = - 0.041, p < 0.174). In all the study groups, AMH showed a weak correlation between FAI and LH/FSH ratio (r = 0.302, p < 0.001 and r = 0.434, p < 0.001, respectively). The sensitivity/specificity for AMH, FAI and LH/FSH ratio were 89/96%, 71/69% and 75/72%, respectively, according to the Youden index. Conclusions We determined the age-dependent reference ranges for serum AMH levels in a large population-based study and calculated the age-specific diagnostic performance of FAI and LH/FSH ratio, which allows physicians to evaluate patients with PCOS who have normal AMH levels. AMH is suggested as the strongest diagnostic marker in patients with PCOS compared to FAI and LH/FSH ratio.