Abstract

FISZLEJDER, L.. Ethiopatogeniae of functional hypothalamic amenorrhea: Interactions of central nervous system and peripherical neuropeptides responses. Rev. argent. endocrinol. metab. [online]. 2008, vol.45, n.2, pp.75-88. ISSN 1851-3034.

Functional Hypothalamic Amenorrhea (FHA) is a complex pathology produced by psicological stress, as observed in amenorrhea nervosa and bulimia or in intensive physical activity (athletas, competitions, classic dancing). Frequently, these factors are associated to quali-quantitative inadequated diets and therefore they induce alterations in the energetic balance (caloric intake, caloric expend and modification in body composition). These factors are usually combinated and they induce hormonal reactions trend to sustain the general metabolic homeostasis. The protagonists of this adaptative process are a "central nervous system circuit" interrelated with "periferical hormonal circuit". The responses to the first, mainly includes functional atenuation of Hypothalamic- Hipophyseal Somatotropic, Prolactin and Thyroid axes, amplification of nocturnal melatonine secretion and hyper adrenal activity. The relationships, to hypothalamic level, of CRH-ACTH, opioid, and dopaminergic systems, and the subsequent inhibition of Gn-RH secretion, constitute a physiopathological mechanism for the development of gonadal disfunction. On the other hand, the degree of alteration in the Gn-RH pulsatility is conditioned by the ethipahogenic, nosologic intensity and time of evolution. Variability and type of irregularity of menstrual cycle observed in competitive athletes, is a demonstrative example. On the other hand, hypoestrogenism and hypoandrogenism in these women affect negatively the general metabolism and, particularly, the osteocalcic system. Osteopenia with its fracture risk is omnipresence in this syndrome. As important as that hypoestrogenism is also one of cardiovascular factor risk. However the administration of contraceptives which combines estrogens plus progesterone, may significantly increase the C-reactive protein level, a known and safety marker of cardiovascular risk. Therefore it induces to take precautions in its administration in these unnourished amenorrheic women. Also, the administration of contraceptives has not showed a substantial benefit in osteoporosis treatment of this patients. A "periferic circuit", functionally interrelated with the "central circuit", is mainly composed by leptin, adiponectine, ghrelin, insulin and IGF1 peptides, coming from fat compartiment (adipokines), gastro-intestinal tract, pancreas and liver, respectively. These peptides, are not only involved in the central mechanisms of appetite and saciety, but they also participate in homeostatic adaptative responses, with the aim of to balance the alteration of middle and phosphocalcic metabolism which affect these patients in a variable form. CONCLUSIONS: FHA, generally related with psychic/physic stress and malnutrition, is a complex syndrome in which the central and peripheral adaptative hormonal responses are mainly important in these women which are affected of a kind of nutritive and general metabolic compromise. Analazing this complex process we considerate that the hypothalamic amenorrhea is obviously a less vital phenomenon.

Keywords : Amenorrhea; Homeostasis; Leptine; Ghrelin; CRH-GnRH; Ethiopatogeniae.

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