Disturbances in gonadal axis in women with anorexia nervosa

Anorexia nervosa negatively affects multiple body systems including the reproductive system.

To assess the disturbances in the hypothalamic-pituitary-gonadal axis (HPG) and the relationship between the gonadotropins and body weight, duration of the disease and amenorrhea we studied 40 female anorexic patients (aged 14-31 years) with a body mass index (BMI) 15.14+/-1.80 kg/m(2) and a degree of weight loss 28.67+/-8.74%. Fifteen healthy, age-matched women with normal weight served as controls.

We investigated the disturbances in the gonadotropin levels before and after stimulation with gonadotropin-releasing hormone (GnRH) 100 microg i.v. One week later 100 mg of clomiphene citrate (CC) was administered orally for 5 days.

Basal levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were significantly lower in the patients. The responses of LH to GnRH were diminished, but those of FSH were exaggerated. However, after clomiphene citrate administration, LH increased 5.4 times whereas FSH increased 1.7 times. The basal levels of LH were significantly correlated with body weight (r=+0.373, p<0.05), BMI (r=+0.385, p<0.01) and percentage of the weight loss (r=-0.356, p<0.05). FSH levels were positively correlated with the duration of the disease (r=+0.481, p<0.01) and amenorrhea (r=+0.540, p<0.01).

Our study demonstrates dissociation in the secretion of gonadotropins after hypothalamic stimulation in anorexic patients. It also reveals the relationship between alterations in the hormones of the HPG axis, not only with the changes in body weight, but also with the duration of the disease.