The Correlation between Sex Hormone-Binding Globulin and Clinical Characteristics According to Anti-Müllerian Hormone in Women with Regular Menstrual Cycles: A Prospective Study

Background: Polycystic ovarian syndrome (PCOS) can be diagnosed when the anti-Mullerian hormone (AMH) levels are high, but in clinic, women who do not meet the diagnosis of PCOS but have elevated AMH levels are often seen. This study aimed to compare the differences in menstrual cycle patterns and hormone levels in women with regular menstrual cycles, but not PCOS, by dividing them into high and low AMH groups. Material and Methods: This multicenter prospective study included 68 healthy women. Participants with regular menstrual cycles were divided into two groups according to their AMH levels. The main outcome measures were menstrual cycle pattern, body mass index, and hormone levels (thyroid stimulating hormone, prolactin, testosterone, sex hormone-binding globulin, and free androgen index), which were compared between the groups according to AMH levels. The ovulation was assessed by performing pelvic ultrasound, and by assessing the hormone levels of the luteinizing hormone and progesterone. Results: The criteria for determining normal and high AMH levels were based on previous literatures. The participants were divided into normal (39 people) and high (29 people) AMH group. No differences were found in age or BMI between the two groups, and no other differences were observed in TSH, prolactin, testosterone, or free androgen index. However, the high AMH group had significantly higher SHBG levels than the normal group (normal group: 65.46 +/- 25.78 nmol/L; high group: 87.08 +/- 45.05 nmol/L) (p = 0.025). Conclusions: This study is the first to analyze the association between SHBG and AMH levels in women with regular menstrual cycles. Elevated AMH levels are associated with increased levels of SHBG levels.