Mechanisms and predictors of menses resumption once normal weight is reached in Anorexia Nervosa

Abstract

Abstract Background: In Anorexia Nervosa (AN), association of weight gain recovery above WHO’s lower limits, and classical nutritional markers normalization appears to be mandatory, but not always sufficient, to restore menses. This may worry both patient and practitioner and disrupt medical care. Therefore, this study was designed to evaluate the ability of anthropometric and hormonal factors to predict menses resumption in anorexia nervosa once normal weight was normalized. Method: AN patients recovering a normal BMI but not their menses (ANRec) were evaluated twice, at visit 1, and 6 months later if bodyweight was maintained over this period (visit 2). The 46 ANRec patients reaching visit 2 were separated into two groups: 20 with persistent amenorrhea (PA-ANRec) and 26 with recovered menses (RM-ANRec). Anthropometric and plasma levels of several hormones, Luteinizing Hormone (LH) pulse and LH response to gonadotrophin releasing hormone (GnRH) injection were then compared between groups at visit 1. Results: RM-ANRec presented with higher plasma level of follicular Stimulating hormone (FSH), Estradiol, inhibin B, LH/GnRH and ghrelin compared to PA-ANRec. ROC curves analyses showed that LH pulses’ number ≥2, LH/GnRH ≥ 33 UI/l and Inhibin B >63 pg/ml predicted menses resumption with high specificity (87, 100 and 100% respectively) and sensitivity (82, 80 and 79% respectively). Conclusions: LH pulses’ number≥2, LH/GnRH≥33UI/l or Inhibin B≥63pg/ml can predict accurately menses resumption in still amenorrheic weight-normalized AN patients if they do not lose weight nor practice intense exercise. Negative parameters could help clinician and patient to maintain efforts to achieve individual metabolic set-point.