Anti-Mullerian hormone and insulin resistance in classic phenotype lean PCOS.

PURPOSE: This study is designed to explore the correlation between AMH levels and IR in normal weight PCOS women.

MATERIALS AND METHODS: This prospective study was conducted on 55 patients, who were admitted to obstetrics and gynecology department of a university clinic. Study group was consisted of 34 patients diagnosed as polycystic ovary syndrome (PCOS) according to the Rotterdam Criteria, whereas control group was consisted of 21 healthy volunteers without any features of clinical or biochemical hyperandrogenism, who had regular menstrual cycles. BMI ≥ 25 kg/m(2) were considered overweight and obese and excluded. Blood samples were obtained during days 2-3 after spontaneous menses or progesterone-induced withdrawal bleeding after overnight fasting for at least 12 h. The weight, height, hip and waist circumferences of the patients were measured. Fasting insulin and glucose (FPG) levels were used for calculating different insulin resistance indexes (Homeostatic Model Assessment (HOMA-IR), Quantitative Insulin Sensitivity Check Index (QUICKI)).

RESULTS: No significant difference was found between PCOS and control groups regarding the mean age, BMI, waist to hip ratio (WHR), mean values of FPG, FPG/insulin ratio and HOMA B (p > 0.05). AMH values were significantly higher in PCOS cases when compared with controls (4.7 vs. 3.4 ng/mL) (p < 0.05).The mean values of HOMA-IR and QUICKI indexes were significantly higher among PCOS cases when compared with controls. E2 levels were significantly lower and Total-T were significantly higher in PCOS patients. When PCOS cases are categorized according to the existence of IR, no difference in Total-T and AMH levels between both groups. Although not statistically significant, a negative correlation of AMH with HOMA-IR and a positive correlation with QUICKI index were found. Among the hormone parameters, AMH was found to be positively correlated with Total-T (r = 0.332, p = 0.013).

CONCLUSION: Although the relation between AMH and androgen production is supported by current evidence, the mechanism underlying the relation between AMH and insulin resistance is not clear yet.