Aging e terapie ormonali

The demographic data, favourable to an increase of the average life span make the surveys about non pa- thological alterations related to aging very interesting thanks to the remedies proposed to fight the unavoi- dable decline of human organism. A concrete example of physiological aging concerns the endocrine observable alterations, in the male, follo- wing the gradual reduction of the circulating andro- gens. Such biochemical aspect, followed by a clinical correspondence as a specific syntomatology, identifies a syndrome whose denomination has been recently updated with the name of «late onset hypogonadism». The remedy proposed to fight its signs and symptoms (reduction of the body mass, augmentation of fat mass, osteopoenia/osteoporosis, libido reduction, erec- tion disfunctions, etc) of such clinical aspect is repre- sented by opotherapy based on testosterone whose efficacy is being positively documented although the results are not yet definite, waiting for further confirma- tion from larger surveys. The observation beyond the gonad area, giving us a further example of age-associated hormonal alteration, underlines the modifications of the endocrine axis for- med by GH/IGF-I and data related to the reduction of dehydroepiandrosterone (DHEA) levels and of its sulfa- te (DHEA-S). The plasmatic levels reduction with the consequent drop of IGF-I, observable in the old sub- jects, seems to correspond to central phenomena of reduced hypophysial stimulation of the hypothalamic GHRH (reduction of the wideness of the secretory rhythm), rather than a reduced secretory capacity by the hypophysis. The GH/IGF-I axis, through the pro- motion of the lipolysis and the insulin-sensitive effect, carries out an anabolic function and is thus considered as an important lean body mass regulator; the pro- gressive loss, observable in the old population, makes the endocrine alterations described in the same group very interesting also in relation with the results of the substitutive therapy with this hormone. The data rela- ted to the aging of muscle response to GH have been recently identified; it has been thus observed that in the aged people’s muscles, there is a reduction in compa- rison with young people, of the capacity to produce the IGH-I isoform, under the GH stimulus and physical resi- stance exercise, which is considered the growth factor capable to mobilize the satellite staminal muscular ele- ments, the Mechano Growth Factor, (MGF). Such fac- tor, produced as alternative splicing of the systemic IGH, superimposable to the hepatic IGF-I, is supposed to coordinate the adaptation processes of the muscle to the exercise (hypertrophy) and could be responsible for the muscle repair, fighting the possible atrophy pre- sent in the old man. The data related to the efficacy of a substitute therapy with GH to restore aged muscles in the same autocrine conditions as young people are still limited but the possibility to act specifically on the dysfunction of the target organ gives high hopes to obtain significant results. Another example of hormonal modification related to aging is offered by the drop of dehydropiandrosterone (DHEA) and of its sulfate (DHEA-S). The several biological functions in which the hormone is implied (cognitive function, glucidic and lypidic metabolism, bone metabolism, sexual and immune functions, etc.), have generated the achieve- ment of some clinic surveys where the efficacy of the DHEA administration with pharmacological doses (50- 100 mg/die) is tested. Today, thanks to the availability of the results deriving from surveys carried out on signi- ficant population samples and with strict scientific cri- teria (double-blind placebo controlled), it is possible to restore the enthusiasm with which the scientific world received the Youth Hormone in the early stages. As a result, apart from contrasting data about the improve- ment of some metabolic parameters, the more reliable surveys describe a non significant efficacy of the DHEA treatment in the healthy man. At the moment, the only clinic condition which draws a certain benefit from DHEA supplementation is hypocorticosurrealism where there has been an improvement of the humour tonus, of asthenia and of well-being in general.