Neuroendocrine aspects of amenorrhea related to stress

Reproductive functions are controlled by a very sophisticated system that is composed by the perfect syncronization of neuronal end endocrinological functions. Hypothalamus is the neuroendocrine gland that discharges GnRH that stimulates LH and FSH secretion from pituitary thus promoting ovarian function. Whatever affects the hypothalamic activity might be able to interfere with the reproductive axis. In fact changes in such sophisticated stimulatory system is able to negatively affect the periodical function of the ovary and may induce amenorrhea. Stressant situations, due to physical, psychologic or metabolic stressors, are able to negatively modulate the hypothalamus-pituitary-ovarian axis (HPO) mainly acting through an impairment of the many neuromodulators and neuropeptides that are produced inside the brain and in the hypothalamic areas. Stress induced amenorrhea is usually called hypothalamic amenorrhea (HA) and affect a consistent percentage of women, independently from the age. Nevertheless, quite often HA is diagnosed in adolescents or in girls below 20 years of age. Undernutrition, excess of training, psychological stress, are able to induce HA and then hypo-estrogenism due to the reduced ovarian activity. When sports or exaggerated training is performed before or during the onset of menarche, a specific delay of menarche might occur, as direct consequence of the unbalance between feeding, energy consumption and psychological stress. Osteopenia and osteoporosis are possible consequence of such situation. Clinicians have to pay great attention to all kind of delay of occurrence of meanarche or of amenorrhea, especially if related to lost of weight, since these might mask adverse environmental situations that might induce HA through an exaggerated stress-induced neuroendocrine response.