Serum LH levels are associated to serum insulin and Anti-Müllerian hormone levels in women with both functional hypothalamic amenorrhoea and polycystic ovarian morphology.

Objective: The aim of the study was to investigate whether serum Luteinizing Hormone (LH) levels in women with Functional Hypothalamic Amenorrhoea (FHA) and Polycystic Ovarian Morphology (PCOM) are still associated to Body Mass Index (BMI) and/or serum insulin and/or Anti-Müllerian Hormone (AMH) levels using a larger population of FHA.

Design: Retrospective observational study (2006-2020).

Participants: Data from 62 FHA patients were used for this study using strict criteria to define them.

Measurements: Serum LH, FSH, 17-hydroxyprogesterone (17-OHP), dehydroepiandrosterone sulphate (DHEA-S), androstenedione, total testosterone, prolactin, Sex Hormone Binding Globulin (SHBG) and AMH levels were measured by immunoassay. To homogenize the AMH values, we converted those obtained after 2015. We defined PCOM with strict criteria: a follicle number per ovary (FNPO) ≥12 or ≥20 per ovary, depending on the date on which the assessment was carried out and the ultrasound device.

Results: Forty-two percentage of our FHA population had PCOM. The PCOM+ group had significantly higher ranks of BMI (p = .024) and serum AMH levels (p = .0001) and significantly lower ranks of serum FSH levels (p = .002). LH was positively correlated with fasting insulin (p = .011) and with AMH (p = .035) in the PCOM+ group only but not with BMI. There was a positive correlation between LH and FSH in both groups.

Conclusion: Our study suggests that GnRH insufficiency in women with PCOM unravels some mechanisms of LH regulation that are poorly documented in the literature and may involve a direct pituitary effect, as suggested by our results with serum insulin and AMH levels.