Growth hormone secretion in response to glucagon stimulation test in healthy middle-aged men

Micmacher, Eduardo; Assumpção, Roberto Pereira; Redorat, Renato Galvão; Spina, Luciana Diniz Carneiro; Cruz, Ivan; Silva, Carla; Vaisman, Mário; Conceição, Flávia Lúcia

doi:10.1590/s0004-27302009000700009

Cited by 21 publications

(8 citation statements)

References 34 publications

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“…GH secretion is regulated by multiple physiologic factors, including age, onset of puberty, nutritional status and body weight [5,6,7]. In adults, several reports have shown that obesity is associated with diminished spontaneous and stimulated GH secretion [7,8,9,10]. Body mass index (BMI) is currently not considered a factor when determining current peak GH cutoff points used in the diagnosis of GH deficiency.…”

Section: Introductionmentioning

confidence: 99%

Influence of Body Mass Index on Growth Hormone Responses to Classic Provocative Tests in Children with Short Stature

Lee

Hwang²

2011

Neuroendocrinology

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Background: The diagnosis of growth hormone (GH) deficiency is based on a reduced peak GH response to provocative tests. However, the provocative tests are poorly reproducible and GH secretion is regulated by physiological parameters, such as body weight and puberty. The aim of this study was to assess the influence of body mass index (BMI) on GH response to provocative testing and to analyze the reproducibility of GH stimulation test. Methods: Clinical data were collected retrospectively by chart review from the Pediatric Endocrine Unit at the Ajou University Hospital. A total of 187 subjects with short stature who completed a GH stimulation testing between 2003 and 2009 were included in the study. Results: Of the 187 subjects, 66 (35.3%) had GH deficiency, while 121 (64.7%) were categorized as having idiopathic short stature. Reliability was calculated for 48 patients with idiopathic short stature who underwent the GH stimulation test twice. A GH response ≧10 ng/ml after retesting was found in 39 patients (81.3%) and a GH response <10 ng/ml was found in 9 patients (18.7%). In a stepwise multivariate analysis, BMI was a significantly independent predictor of peak GH. Elevated BMI was negatively associated with peak plasma GH levels. Conclusions: The lack of reliability of GH values in response to pharmacological stimuli should be taken into account in the diagnosis of GH deficiency. Also, higher BMI is associated with lower GH secretion. BMI should be measured and GH results appropriately interpreted for all subjects undergoing GH stimulation testing.

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Section: Introductionmentioning

confidence: 99%

Influence of Body Mass Index on Growth Hormone Responses to Classic Provocative Tests in Children with Short Stature

Lee

Hwang²

2011

Neuroendocrinology

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“…However, whether GH can alleviate the eff ects of HD induced obesity in old rats is not presently known. The expected decline of GH secretion that follows aging, named somatopause [28] is implicated, directly or indirectly, with physiological changes. After 30 days of GH treatment there was a positive response to the GH applications, as seen by the increased IGF-I concentration in C + GH group ( • ▶ Table 1 ).…”

Section: Discussion ▼mentioning

confidence: 99%

Calorimetry, Morphometry, Oxidative Stress, and Cardiac Metabolic Response to Growth Hormone Treatment in Obese and Aged Rats

Seiva¹,

Chuffa²,

Ebaid³

et al. 2011

Horm Metab Res

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This study investigated the effects of growth hormone therapy on energy expenditure, lipid profile, oxidative stress and cardiac energy metabolism in aging and obesity conditions. Life expectancy is increasing in world population and with it, the incidence of public health problems such as obesity and cardiac alterations. Because growth hormone (GH) concentration is referred to be decreased in aging conditions, a question must be addressed: what is the effect of GH on aging related adverse changes? To investigate the effects of GH on cardiac energy metabolism and its association with calorimetric parameters, lipid profile and oxidative stress in aged and obese rats, initially 32 male Wistar rats were divided into 2 groups (n=16), C: given standard-chow and water; H: given hypercaloric-chow and receiving 30% sucrose in its drinking water. After 45 days, both C and H groups were divided into 2 subgroups (n=8), C+PL: standard-chow, water, and receiving saline subcutaneously; C+GH: standard-chow, water, and receiving 2 mg/kg/day rhGH subcutaneously; H+PL: hypercaloric-chow, 30% sucrose, receiving saline subcutaneously; H+GH: hypercaloric-chow, 30% sucrose, receiving rhGH subcutaneously. After 30 days, C+GH and H+PL rats had higher body mass index, Lee-index, body fat content, percent-adiposity, serum triacylglycerol, cardiac lipid-hydroperoxide, and triacylglycerol than C+PL. Energy-expenditure (RMR)/body weight, oxygen consumption and fat-oxidation were higher in H+GH than in H+PL. LDL-cholesterol was highest in H+GH rats, whereas cardiac pyruvate-dehydrogenase and phosphofrutokinase were higher in H+GH and H+PL rats than in C+PL. In conclusion, the present study brought new insights on aging and obesity, demonstrating for the first time that GH therapy was harmful in aged and obesity conditions, impairing calorimetric parameters and lipid profile. GH was disadvantageous in control old rats, having undesirable effects on triacylglycerol accumulation and cardiac oxidative stress.

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“…Twenty-nine subjects were screened for a project about somatotrophic profile in healthy men over 50 years old (which includes this paper) and have resulted in other published studies [15, 16]. After that, fourteen from the 29 initial patients agreed to participate in this part of the project that included the evaluation of muscle strength in GH x placebo replacement; those subjects who gave up had personal problems, such as work compromises and address change.…”

Section: Methodsmentioning

confidence: 99%

Effects of Growth Hormone Administration on Muscle Strength in Men over 50 Years Old

Tavares

Micmacher

Biesek

et al. 2013

International Journal of Endocrinology

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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.

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Growth hormone secretion in response to glucagon stimulation test in healthy middle-aged men

Cited by 21 publications

References 34 publications

Influence of Body Mass Index on Growth Hormone Responses to Classic Provocative Tests in Children with Short Stature

Influence of Body Mass Index on Growth Hormone Responses to Classic Provocative Tests in Children with Short Stature

Calorimetry, Morphometry, Oxidative Stress, and Cardiac Metabolic Response to Growth Hormone Treatment in Obese and Aged Rats

Effects of Growth Hormone Administration on Muscle Strength in Men over 50 Years Old

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