Anti-Müllerian hormone in anorexia nervosa: a biomarker of nutritional status and reproductive phenotype

To investigate Anti-Müllerian Hormone (AMH) levels in women with anorexia nervosa (AN) compared to individuals with constitutional thinness (CT) and healthy controls, and to evaluate the association between AMH, body mass index (BMI), and weight recovery.

This monocentric cross-sectional study included 191 women with AN, 41 with CT, and 55 controls. A subgroup of 42 patients with AN was reassessed after weight recovery. Hormonal, metabolic, and psychological parameters were analyzed. AMH was measured using a validated electrochemiluminescence immunoassay. Comparisons and correlations were performed using nonparametric tests and Pearson coefficients.

Mean AMH plasma level was higher in patients with AN (30.5 ± 1.6 pmol/l) than in controls (23.3 ± 2.5 pmol/l, p = 0.0252) and CT (21.4 ± 2.7 pmol/l, p = 0.0088). AMH was positively correlated with BMI, leptin, FSH, and LH in the AN group, and inversely associated with disease duration. AMH was the lowest in extreme undernutrition state (BMI ≤ 13 kg/m²: AMH: 19.5 ± 4.4pmol/l) and the highest in moderate undernutrition state (BMI 16.5-18.5 kg/m²: AMH:35.8 ± 3.1pmol/l; p = 0.0343 vs. previous). During weight recovery, AMH remained stable overall but tended to decrease in patients who regained menstrual cycles.

Mean AMH is globally elevated in AN, but modulated by nutritional status, being very low in extreme undernutrition and higher during partial recovery, remaining elevated with weight normalization in patients with persistent amenorrhea. AMH might reflect the severity of undernutrition in AN, with low AMH marking the most severe forms, and relatively higher AMH indicating some preserved or recoverable reproductive function, helping the clinician in assessing reproductive prognosis in AN.