Supra-physiological rhGH administration induces gender-related differences in the hypothalamus-pituitary-thyroid (HPT) axis in healthy individuals.

PURPOSE: The use of recombinant human growth hormone (rhGH) is a common habit among athletes. While the effects of rhGH administration have been described with contrasting results in males, no data exist in females to date. The aim of the present study was to evaluate the effects of rhGH administration on TSH, FT4 and FT3 levels and the time requested to return to baseline values after treatment withdrawal. METHODS: Twenty-one healthy trained male and female athletes were treated with 0.03 mg rhGH/kg body mass 6 days/week for 3 weeks. We collected blood samples immediately before the first daily rhGH administration, at 3, 4, 8, 15 and 21 days of treatment and at 3 and 9 days after rhGH withdrawal. RESULTS: In males, rhGH administration induced a significant (p < 0.01) early and stable TSH decrease and IGF-I increase, and a delayed FT4 reduction without FT3 modification, suggesting a central regulatory mechanism. In females, rhGH administration induced a significant (p < 0.01) early and transient TSH decrease and IGF-I increase, and a transient reduction in FT4 without any changes in FT3 concentrations. rhGH withdrawal was associated with a prompt normalization of TSH and FT4 levels in males, while in females the effects of rhGH treatment had already disappeared during the last period of treatment. CONCLUSION: We suggest that rhGH inhibits TSH at central level both in males and females. The pattern of normalization was different in the two genders probably due to gonadal steroids modulation on GH-IGF-I axis.

Efficacy of wrists overnight compression (HT 7 point) on insomniacs: possible role of melatonin?

AIM: Insomnia is a major problem which decreases life quality. Many causes are involved with it and anxiety is often associated. The underlying mechanism is not completely understood, even though different factors seem to be associated. Among them melatonin and its circadian rhythm is thought to have an important role. In addition, acupressure and acupuncture are known to ameliorate insomnia and anxiety, when a specific wrist point is stimulated (HT 7 Shenmen). With these bases, the aim of the present study has been to evaluate the efficacy of an acupressure device, ''H7-insomnia control'', positioned on HT 7 points, during the night, in terms of general health and anxiety levels, together with the evaluation of sleep quality and the urinary melatonin metabolite 6-hydroxymelatonin sulphate determination, in a number of insomniacs. METHODS: Forty patients with insomnia were divided into two groups and randomly received either the H7 or placebo treatments, in a double-blind protocol, for 20 nights. Before and after treatments every subject answered a series of questionnaires (General Health Questionnaire 28 items; State-Trait Anxiety Inventory; Pittsburgh Sleep Quality Index) and collected 24 h urines, divided into two samples of 12 h each. Urinary melatonin metabolite was then determined using a RIA method. RESULTS: Data obtained indicate that the device H7-insomnia control is efficacious to ameliorate quality of sleep and reduce anxiety levels in insomniacs, at a higher extent than in the placebo group. In addition, the 24 hours urinary melatonin metabolite rhythm, obtained at the end of treatment, was considered as being normal in a higher percentage of H7-treated patients, with respect to the placebo group. CONCLUSION: It is plausible to hypothesize that the wrist acupressure device might be considered a valid tool, without adverse effects since it does not contain pharmaceutical products, that is able to naturally ameliorate sleep quality in insomniacs, acting through a not jet completely clarified mechanism, that may involve melatonin.

Acute amino acids supplementation enhances pituitary responsiveness in athletes.

PURPOSE: The purpose of this study was to determine the effect of a mixture of amino acids on pituitary responsiveness to a stimulation test (GnRH + CRH) in athletes. METHODS: In a double blinded counterbalanced experimental protocol, 10 moderately trained male athletes performed the pituitary stimulation test 60 min after a single oral administration of a placebo (P1-AS) or an amino acid mixture solution (AS) (L-arginine hydrochloride 100 mg x kg(-1) + L-ornithine hydrochloride 80 mg x kg(-1) + L-branched chain amino acids 140 mg x kg(-1): 50% L-leucine, 25% L-isoleucine, 25% L-valine) on two different occasions. Plasma ACTH, LH, FSH, GH, and cortisol were evaluated before (-60, -30, 0 min) and after (+15, +30, +45, +60, +90 min) the stimulation test. RESULTS: The ACTH, LH and FSH response to CRH + GnRH was significantly higher in AS group both as absolute values and area under curve (AUC) values than in P1-AS group. Pre-test and post-test cortisol AUC levels were significantly higher in P1-AS group although a higher percent increase in post-test cortisol was found in AS group. The total GH-AUC was higher in AS group and, as expected, the absolute GH concentrations at different time points were not influenced by CRH + GnRH administration. CONCLUSION: The amino acid mixture used enhanced the ACTH, LH, and FSH response to CRH + GnRH.