Growth hormone (GH) use has been speculated to improve physical capacity in subjects without GH deficiency (GHD) through stimulation of collagen synthesis in the tendon and skeletal muscle, which leads to better exercise training and increased muscle strength. In this context, the use of GH in healthy elderly should be an option for increasing muscle strength. Our aim was to evaluate the effect of GH therapy on muscle strength in healthy men over 50 years old. Fourteen healthy men aged 50–70 years were evaluated at baseline for body composition and muscle strength (evaluated by leg press and bench press exercises, which focus primarily on quadriceps—lower body part and pectoralis major—upper body part—muscles, resp.). Subjects were randomised into 2 groups: GH therapy (7 subjects) and placebo (7 subjects) and reevaluated after 6 months of therapy. Thirteen subjects completed the study (6 subjects in the placebo group and 7 subjects in the GH group). Subjects of both groups were not different at baseline. After 6 months of therapy, muscle strength in the bench press responsive muscles did not increase in both groups and showed a statistically significant increase in the leg press responsive muscles in the GH group. Our study demonstrated an increase in muscle strength in the lower body part after GH therapy in healthy men. This finding must be considered and tested in frail older populations, whose physical incapacity is primarily caused by proximal muscle weakness. The trial was registered with NCT01853566.
Objective: To investigate the growth hormone (GH) response to glucagon stimulation test (GST) in a population of healthy men over 50 years old in comparison to insulin tolerance test (ITT), analysis of the spontaneous 24-hour GH profile and insulin-like growth factor 1 (IGF-I). Me thods: 27 healthy men aged between 51 and 65 years were tested. Results: Using non-parametric correlation analysis, a positive correlation between GH peak after GST and mean IGF-I (r = 0.528; p = 0.005) was found, as well with GH peak in 24-hour profile (r = 0.494; p = 0.009). No correlation was found comparing GH peak after ITT with the same parameters. Ten subjects presented GH peak of less than 3.0 μg/L after GST, none confirmed in ITT. Conclusions: GH peak response to GST was lower than ITT, but it showed a positive correlation with mean IGF-I and also with GH peak in 24-hour profile. However, GST should not be used to differentiate organic growth hormone deficiency (GDH) from the expected decline on GH secretion due to aging. Arq Bras Endocrinol Metab. 2009;53(7):853-8.
KeywordsGrowth hormone; somatopause; glucagon RESUMO Objetivo: Investigar a resposta do hormônio do crescimento (GH) ao teste de estímulo com glucagon (GST) numa população de homens saudáveis acima dos 50 anos de idade, em comparação ao teste de tolerância à insulina (ITT), além da análise do perfil de secreção espontânea de GH nas 24 horas e fator de crescimento semelhante à insulina (IGF-I) basal. Métodos: 27 homens, com idades entre 51 e 65 anos, foram submetidos aos testes. Resultados: Utilizando análise de correlação não paramétrica, encontrou-se correlação positiva entre o pico de GH pós-GST e a média de IGF-I (r = 0,528; p = 0,005), e também com o pico espontâneo do GH no perfil de 24 horas (r = 0,494; p = 0,009). Não houve correlação do pico de GH pós-ITT com os mesmos parâmetros. Dez indivíduos apresentaram pico de GH após GST inferior a 3,0 μg/L, sem confirmação no ITT. Conclusões: O pico de GH pós-GST foi menor do que o obtido pós-ITT, porém demonstrou correlação positiva com a média de IGF-I e o pico de GH na secreção espontânea de 24 horas. Entretanto, o GST não demonstrou ser um bom teste para distinguir entre deficiência de hormônio de crescimento (DGH) e somatopausa. Arq Bras Endocrinol Metab. 2009;53(7):853-8.
DescritoresHormônio do crescimento; somatopausa; glucagon
We conclude that TAI is independently associated with is a higher risk of miscarriage in a population of unselected pregnant presenting a low risk of miscarriage.
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