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Schaupp A, Bidlingmaier M, Martini S, Reincke M, Schluessel S, Schmidmaier R, Drey M. Resistance training-induced improvement in physical function is not associated to changes in endocrine somatotropic activity in prefrail older adults. Arch Gerontol Geriatr 2022; 103:104792. [PMID: 36037722 DOI: 10.1016/j.archger.2022.104792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/02/2022] [Accepted: 08/13/2022] [Indexed: 11/02/2022]
Abstract
CONTEXT Resistance training improves muscle function in prefrail and frail elderly. The role of the somatotropic axis in this physiologic process remains unclear. Insulin-like growth factor I (IGF-I) and its associated proteins Insulin-like growth factor binding protein 3 (IGFBP3) and acid labile subunit (ALS) build a circulating ternary complex that mediates growth hormone (GH) effects on peripheral organs and can serve as a measure of endocrine somatotropic activity. OBJECTIVE The aim of this study was to assess the association between resistance training-induced changes in physical performance and basal levels of IGF-I, IGFBP-3 and ALS in prefrail older adults. METHODS 69 prefrail community-dwelling older adults, aged 65 to 94 years, were randomly assigned to a 12-week period of strength or power training or to a control group. The study was registered at clinicaltrials.gov as NCT00783159. Serum concentrations of IGF-I, IGFBP-3 and ALS were measured at rest before and after the intervention. Hormonal differences were examined in relation to changes in physical performance assessed by the Short Physical Performance Battery (SPPB). RESULTS While resistance training led to significant improvements in SPPB score it did not induce significant differences in somatotropic hormone concentrations. Pre- and post-intervention changes in IGF-I, IGFBP-3, ALS or IGF/IGFBP-3 molar ratio were not related to the intervention mode, even after adjustment for age, sex, nutritional status, as well as SPPB and hormone concentrations at baseline. CONCLUSION Training-induced improvements in physical performance in prefrail older adults were not associated with significant changes in endocrine somatotropic activity.
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Affiliation(s)
- Anna Schaupp
- Department of Medicine IV, University Hospital, Ludwig-Maximilians-Universität Munich, Ziemssenstraße 5, Munich 80336, Germany.
| | - Martin Bidlingmaier
- Department of Medicine IV, University Hospital, Ludwig-Maximilians-Universität Munich, Ziemssenstraße 5, Munich 80336, Germany
| | - Sebastian Martini
- Department of Medicine IV, University Hospital, Ludwig-Maximilians-Universität Munich, Ziemssenstraße 5, Munich 80336, Germany
| | - Martin Reincke
- Department of Medicine IV, University Hospital, Ludwig-Maximilians-Universität Munich, Ziemssenstraße 5, Munich 80336, Germany
| | - Sabine Schluessel
- Department of Medicine IV, University Hospital, Ludwig-Maximilians-Universität Munich, Ziemssenstraße 5, Munich 80336, Germany
| | - Ralf Schmidmaier
- Department of Medicine IV, University Hospital, Ludwig-Maximilians-Universität Munich, Ziemssenstraße 5, Munich 80336, Germany
| | - Michael Drey
- Department of Medicine IV, University Hospital, Ludwig-Maximilians-Universität Munich, Ziemssenstraße 5, Munich 80336, Germany
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Bilski J, Pierzchalski P, Szczepanik M, Bonior J, Zoladz JA. Multifactorial Mechanism of Sarcopenia and Sarcopenic Obesity. Role of Physical Exercise, Microbiota and Myokines. Cells 2022; 11:cells11010160. [PMID: 35011721 PMCID: PMC8750433 DOI: 10.3390/cells11010160] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/27/2021] [Accepted: 12/31/2021] [Indexed: 02/07/2023] Open
Abstract
Obesity and ageing place a tremendous strain on the global healthcare system. Age-related sarcopenia is characterized by decreased muscular strength, decreased muscle quantity, quality, and decreased functional performance. Sarcopenic obesity (SO) is a condition that combines sarcopenia and obesity and has a substantial influence on the older adults’ health. Because of the complicated pathophysiology, there are disagreements and challenges in identifying and diagnosing SO. Recently, it has become clear that dysbiosis may play a role in the onset and progression of sarcopenia and SO. Skeletal muscle secretes myokines during contraction, which play an important role in controlling muscle growth, function, and metabolic balance. Myokine dysfunction can cause and aggravate obesity, sarcopenia, and SO. The only ways to prevent and slow the progression of sarcopenia, particularly sarcopenic obesity, are physical activity and correct nutritional support. While exercise cannot completely prevent sarcopenia and age-related loss in muscular function, it can certainly delay development and slow down the rate of sarcopenia. The purpose of this review was to discuss potential pathways to muscle deterioration in obese individuals. We also want to present the current understanding of the role of various factors, including microbiota and myokines, in the process of sarcopenia and SO.
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Affiliation(s)
- Jan Bilski
- Department of Biomechanics and Kinesiology, Chair of Biomedical Sciences, Faculty of Health Sciences, Institute of Physiotherapy, Jagiellonian University Medical College, 31-008 Krakow, Poland
- Correspondence: ; Tel.: +48-12-421-93-51
| | - Piotr Pierzchalski
- Department of Medical Physiology, Chair of Biomedical Sciences, Faculty of Health Sciences, Institute of Physiotherapy, Jagiellonian University Medical College, 31-126 Krakow, Poland; (P.P.); (J.B.)
| | - Marian Szczepanik
- Department of Medical Biology, Chair of Biomedical Sciences, Faculty of Health Sciences, Institute of Physiotherapy, Jagiellonian University Medical College, 31-034 Krakow, Poland;
| | - Joanna Bonior
- Department of Medical Physiology, Chair of Biomedical Sciences, Faculty of Health Sciences, Institute of Physiotherapy, Jagiellonian University Medical College, 31-126 Krakow, Poland; (P.P.); (J.B.)
| | - Jerzy A. Zoladz
- Chair of Exercise Physiology and Muscle Bioenergetics, Faculty of Health Sciences, Jagiellonian University Medical College, 31-066 Krakow, Poland;
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Ye G, Xiao Z, Luo Z, Huang X, Abdelrahim MEA, Huang W. Resistance training effect on serum insulin-like growth factor 1 in the serum: a meta-analysis. Aging Male 2020; 23:1471-1479. [PMID: 32844706 DOI: 10.1080/13685538.2020.1801622] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The resistance exercise has drawn considerable attention to the level of insulin-like growth factor 1 in the serum. However, the relationship between resistance exercise and the level of insulin-like growth factor 1 in the serum is conflicting. This meta-analysis was performed to evaluate this relationship. METHODS A systematic literature search up to May 2020 was performed and 22 studies were detected with 680 subjects. They reported relationships between resistance exercise and the level of insulin-like growth factor 1 in the serum. Odds ratio (OR) with 95% confidence intervals (CIs) was calculated comparing the resistance exercise and the level of insulin-like growth factor 1 in the serum using the continuous method with a random or fixed-effect model. RESULTS Significantly higher insulin-like growth factor 1 was observed in subjects performing resistance training for less than 16 weeks (OR, 4.03; 95% CI, 2.49-5.57, p<.001); subjects performing resistance training for more than 16 weeks (OR, 11.55; 95% CI, 6.58-16.52, p<.001); subjects older than 60 years (OR, 11.88; 95% CI, 9.84-13.93, p<.001); females (OR, 3.87; 95% CI, 2.26-5.49, p<.001) and males (OR, 16.82; 95% CI, 7.29-26.35, p<.001). However, significantly lower insulin-like growth factor 1 was observed in subjects younger than 60 years (OR, -4.80; 95% CI, -7.74 to -1.86, p=.001). CONCLUSIONS However, the resistance exercise significantly increases insulin-like growth factor 1 in subjects older than 60 years, both males and females, and subjects performing resistance exercise for all any period. Surprisingly, resistance exercise significantly decreases insulin-like growth factor 1 in subjects younger than 60 years. This relationship forces us to recommend the resistance exercise to improve insulin-like growth factor 1 in serum.
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Affiliation(s)
- Guanlun Ye
- Department of Endocrinology, Guangdong Provincial People's Hospital's Nanhai Hospital, Foshan, China
| | - Zhifang Xiao
- Department of Endocrinology, Affiliated Nanhua Hospital, University of South China, Hengyang, China
| | - Zhuozhang Luo
- Department of Endocrinology, Guangdong Provincial People's Hospital's Nanhai Hospital, Foshan, China
| | - Xiaomin Huang
- Department of Endocrinology, Guangdong Provincial People's Hospital's Nanhai Hospital, Foshan, China
| | - Mohamed E A Abdelrahim
- Clinical Pharmacy Department, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - Wenlong Huang
- Department of General Surgery, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
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Exercise-Induced Myokines can Explain the Importance of Physical Activity in the Elderly: An Overview. Healthcare (Basel) 2020; 8:healthcare8040378. [PMID: 33019579 PMCID: PMC7712334 DOI: 10.3390/healthcare8040378] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 09/25/2020] [Accepted: 09/27/2020] [Indexed: 12/12/2022] Open
Abstract
Physical activity has been found to aid the maintenance of health in the elderly. Exercise-induced skeletal muscle contractions lead to the production and secretion of many small proteins and proteoglycan peptides called myokines. Thus, studies on myokines are necessary for ensuring the maintenance of skeletal muscle health in the elderly. This review summarizes 13 myokines regulated by physical activity that are affected by aging and aims to understand their potential roles in metabolic diseases. We categorized myokines into two groups based on regulation by aerobic and anaerobic exercise. With aging, the secretion of apelin, β-aminoisobutyric acid (BAIBA), bone morphogenetic protein 7 (BMP-7), decorin, insulin-like growth factor 1 (IGF-1), interleukin-15 (IL-15), irisin, stromal cell-derived factor 1 (SDF-1), sestrin, secreted protein acidic rich in cysteine (SPARC), and vascular endothelial growth factor A (VEGF-A) decreased, while that of IL-6 and myostatin increased. Aerobic exercise upregulates apelin, BAIBA, IL-15, IL-6, irisin, SDF-1, sestrin, SPARC, and VEGF-A expression, while anaerobic exercise upregulates BMP-7, decorin, IGF-1, IL-15, IL-6, irisin, and VEGF-A expression. Myostatin is downregulated by both aerobic and anaerobic exercise. This review provides a rationale for developing exercise programs or interventions that maintain a balance between aerobic and anaerobic exercise in the elderly.
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Andreotti DZ, Silva JDN, Matumoto AM, Orellana AM, de Mello PS, Kawamoto EM. Effects of Physical Exercise on Autophagy and Apoptosis in Aged Brain: Human and Animal Studies. Front Nutr 2020; 7:94. [PMID: 32850930 PMCID: PMC7399146 DOI: 10.3389/fnut.2020.00094] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 05/22/2020] [Indexed: 12/13/2022] Open
Abstract
The aging process is characterized by a series of molecular and cellular changes over the years that could culminate in the deterioration of physiological parameters important to keeping an organism alive and healthy. Physical exercise, defined as planned, structured and repetitive physical activity, has been an important force to alter physiology and brain development during the process of human beings' evolution. Among several aspects of aging, the aim of this review is to discuss the balance between two vital cellular processes such as autophagy and apoptosis, based on the fact that physical exercise as a non-pharmacological strategy seems to rescue the imbalance between autophagy and apoptosis during aging. Therefore, the effects of different types or modalities of physical exercise in humans and animals, and the benefits of each of them on aging, will be discussed as a possible preventive strategy against neuronal death.
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Affiliation(s)
- Diana Zukas Andreotti
- Laboratory of Molecular and Functional Neurobiology, Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Josiane do Nascimento Silva
- Laboratory of Molecular and Functional Neurobiology, Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Amanda Midori Matumoto
- Laboratory of Molecular and Functional Neurobiology, Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Ana Maria Orellana
- Laboratory of Molecular Neuropharmacology, Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Paloma Segura de Mello
- Laboratory of Molecular Neuropharmacology, Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Elisa Mitiko Kawamoto
- Laboratory of Molecular and Functional Neurobiology, Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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6
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The effect of resistance training on serum insulin-like growth factor 1(IGF-1): A systematic review and meta-analysis. Complement Ther Med 2020; 50:102360. [DOI: 10.1016/j.ctim.2020.102360] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 02/25/2020] [Accepted: 02/25/2020] [Indexed: 02/07/2023] Open
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The Effect of Exercise on Glucoregulatory Hormones: A Countermeasure to Human Aging: Insights from a Comprehensive Review of the Literature. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16101709. [PMID: 31096708 PMCID: PMC6572009 DOI: 10.3390/ijerph16101709] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 04/25/2019] [Accepted: 05/11/2019] [Indexed: 11/17/2022]
Abstract
Hormones are secreted in a circadian rhythm, but also follow larger-scale timetables, such as monthly (hormones of the menstrual cycle), seasonal (i.e., winter, summer), and, ultimately, lifespan-related patterns. Several contexts modulate their secretion, such as genetics, lifestyle, environment, diet, and exercise. They play significant roles in human physiology, influencing growth of muscle, bone, and regulating metabolism. Exercise training alters hormone secretion, depending on the frequency, duration, intensity, and mode of training which has an impact on the magnitude of the secretion. However, there remains ambiguity over the effects of exercise training on certain hormones such as glucoregulatory hormones in aging adults. With advancing age, there are many alterations with the endocrine system, which may ultimately alter human physiology. Some recent studies have reported an anti-aging effect of exercise training on the endocrine system and especially cortisol, growth hormone and insulin. As such, this review examines the effects of endurance, interval, resistance and combined training on hormones (i.e., at rest and after) exercise in older individuals. We summarize the influence of age on glucoregulatory hormones, the influence of exercise training, and where possible, examine masters' athletes' endocrinological profile.
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Lei Q, Pan Q, Li N, Zhou Z, Zhang J, He X, Peng S, Li G, Sidhu K, Chen S, Hua J. H19 regulates the proliferation of bovine male germline stem cells via IGF-1 signaling pathway. J Cell Physiol 2018; 234:915-926. [PMID: 30069947 DOI: 10.1002/jcp.26920] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 06/13/2018] [Indexed: 01/12/2023]
Abstract
Self-renewal and differentiation of male germline stem cells (mGSCs) provide the basic function for continual spermatogenesis. Studies of in vitro culture of germline stem cells are important and meaningful for basic biological research and practical application. Growth factors, such as GDNF, bFGF, CSF1, and EGF, could maintain the self-renewal of mGSCs. Insulin-like growth factor 1 (IGF-1), an important growth factor, and its pathway have been reported to maintain the survival of several types of stem cells and play important roles in male reproduction. However, the mechanism through which the IGF-1 pathway acts to regulate the self-renewal of mGSCs remains unclear. We analyzed the effect of IGF-1 on the proliferation and apoptosis of bovine mGSCs. We evaluated the expression profile of long noncoding RNA (LncRNA) H19 in bovine and mouse tissues. Moreover, we investigated whether LncRNA H19 could regulate the IGF-1 pathway. Results showed that IGF-1 could activate the phosphorylation of AKT and ERK signaling pathways, and the IGF-1 pathway played an important role in regulating the proliferation and apoptosis of bovine mGSCs. The proliferation rate of mGSCs decreased, whereas the apoptosis rate of mGSCs increased when the IGF-1 receptor (IGF-1R) was blocked using the IGF-1R-specific inhibitor (picropodophyllin). LncRNA H19 could regulate the IGF-1 signaling pathway and, consequently, the proliferation and apoptosis of mGSCs. The number of cells in the seminiferous tubule decreased when H19 was interfered by injecting a virus-containing supernatant. Hence, LncRNA H19 participated in the regulation of the proliferation and apoptosis of mGSCs via the IGF-1 signaling pathway.
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Affiliation(s)
- Qijing Lei
- College of Veterinary Medicine, Shaanxi Centre of Stem Cells Engineering and Technology, Northwest A&F University, Yangling, China
| | - Qin Pan
- College of Veterinary Medicine, Shaanxi Centre of Stem Cells Engineering and Technology, Northwest A&F University, Yangling, China
| | - Na Li
- College of Veterinary Medicine, Shaanxi Centre of Stem Cells Engineering and Technology, Northwest A&F University, Yangling, China
| | - Zhe Zhou
- College of Veterinary Medicine, Shaanxi Centre of Stem Cells Engineering and Technology, Northwest A&F University, Yangling, China
| | - Juqing Zhang
- College of Veterinary Medicine, Shaanxi Centre of Stem Cells Engineering and Technology, Northwest A&F University, Yangling, China
| | - Xin He
- College of Veterinary Medicine, Shaanxi Centre of Stem Cells Engineering and Technology, Northwest A&F University, Yangling, China
| | - Sha Peng
- College of Veterinary Medicine, Shaanxi Centre of Stem Cells Engineering and Technology, Northwest A&F University, Yangling, China
| | - Guangpeng Li
- Key Laboratory of Mammalian Reproductive Biology and Biotechnology of the Ministry of Education, College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Kuldip Sidhu
- Centre for Healthy Brain Ageing, UNSW Medicine, High St Randwick, NSW, Australia
| | - Shulin Chen
- College of Veterinary Medicine, Shaanxi Centre of Stem Cells Engineering and Technology, Northwest A&F University, Yangling, China
| | - Jinlian Hua
- College of Veterinary Medicine, Shaanxi Centre of Stem Cells Engineering and Technology, Northwest A&F University, Yangling, China
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Yau SW, Harcourt BE, Kao KT, Alexander EJ, Russo VC, Werther GA, Sabin MA. Serum IGFBP-2 levels are associated with reduced insulin sensitivity in obese children. Clin Obes 2018; 8:184-190. [PMID: 29493116 DOI: 10.1111/cob.12245] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 01/18/2018] [Accepted: 01/24/2018] [Indexed: 01/20/2023]
Abstract
Insulin-like growth factor binding protein 2 (IGFBP-2) may represent a critical link between body composition and insulin sensitivity. We investigated the relationship between circulating IGFBP-2 levels, body composition, insulin sensitivity, energy intake and physical activity in children with obesity. Children were recruited via the Weight Management Service at the Royal Children's Hospital, Melbourne, as part of the Childhood Overweight BioRepository of Australia (COBRA). Comprehensive anthropometric, biochemical and environmental data were collected and compared to serum IGFBP-2 levels (measured by enzyme-linked immunosorbent assay). Multiple regression modelling was used to assess the influence of circulating IGFBP-2 levels on anthropometric and biochemical measures. One hundred and ninety-four children were included in this study (46% male). Circulating IGFBP-2 negatively correlated with age, anthropometric measures, blood pressure and insulin concentration. Positive associations were observed between insulin sensitivity index-homeostasis model assessment (ISI-HOMA) and serum IGFBP-2. In multiple regression modelling, IGFBP-2 significantly contributes to variance in systolic blood pressure (-19%, P < 0.05), circulating triglycerides (-16%, P < 0.05) and ISI-HOMA (18%, P < 0.05). No associations were observed between dietary energy intake or physical activity and IGFBP-2 levels. Circulating IGFBP-2 levels in children with obesity correlate inversely with body mass and markers of metabolic dysfunction, and positively with insulin sensitivity. These findings suggest that reduced levels of IGFBP-2 may play an important role in the pathogenesis of obesity complications in early life.
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Affiliation(s)
- S W Yau
- Obesity Research, Murdoch Children's Research Institute and The Royal Children's Hospital, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - B E Harcourt
- Obesity Research, Murdoch Children's Research Institute and The Royal Children's Hospital, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - K-T Kao
- Obesity Research, Murdoch Children's Research Institute and The Royal Children's Hospital, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - E J Alexander
- Obesity Research, Murdoch Children's Research Institute and The Royal Children's Hospital, Melbourne, Australia
| | - V C Russo
- Obesity Research, Murdoch Children's Research Institute and The Royal Children's Hospital, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - G A Werther
- Obesity Research, Murdoch Children's Research Institute and The Royal Children's Hospital, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - M A Sabin
- Obesity Research, Murdoch Children's Research Institute and The Royal Children's Hospital, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
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IGFBP-2: The dark horse in metabolism and cancer. Cytokine Growth Factor Rev 2015; 26:329-46. [DOI: 10.1016/j.cytogfr.2014.12.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 12/09/2014] [Indexed: 12/29/2022]
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Spatial memory is improved by aerobic and resistance exercise through divergent molecular mechanisms. Neuroscience 2012; 202:309-17. [DOI: 10.1016/j.neuroscience.2011.11.029] [Citation(s) in RCA: 230] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 11/10/2011] [Accepted: 11/10/2011] [Indexed: 01/05/2023]
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Llorens-Martín M, Torres-Alemán I, Trejo JL. Exercise modulates insulin-like growth factor 1-dependent and -independent effects on adult hippocampal neurogenesis and behaviour. Mol Cell Neurosci 2010; 44:109-17. [PMID: 20206269 DOI: 10.1016/j.mcn.2010.02.006] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 02/22/2010] [Accepted: 02/23/2010] [Indexed: 11/24/2022] Open
Abstract
While physical exercise clearly has beneficial effects on the brain, fomenting neuroprotection as well as promoting neural plasticity and behavioural modifications, the cellular and molecular mechanisms mediating these effects are not yet fully understood. We have analyzed sedentary and exercised animals to examine the effects of activity on behaviour (spatial memory and anxiety--as measured by a fear/exploration conflict test), as well as on adult hippocampal neurogenesis (a well-known form of neural plasticity). We have found that the difference in activity between sedentary and exercised animals induced a decrease in the fear/exploration conflict scores (a measure usually accepted as an anxiolytic effect), while no changes are evident in terms of spatial memory learning. The short-term anxiolytic-like effect of exercise was IGF1-dependent and indeed, the recall of hippocampus-dependent spatial memory is impaired by blocking serum IGF1 (as observed by measuring serum IGF levels in the same animals used to analyze the behaviour), irrespective of the activity undertaken by the animals. On the other hand, activity affected neurogenesis as reflected by counting the numbers of several cell populations, while the dependence of this effect on IGF1 varied according to the differentiation state of the new neurons. Hence, while proliferating precursors and postmitotic immature neurons (measured by means of doublecortin and calretinin) are influenced by serum IGF1 levels in both sedentary and exercised animals, premitotic immature neurons (an intermediate stage) respond to exercise independently of serum IGF1. Therefore, we conclude that physical exercise has both serum IGF1-independent and -dependent effects on neural plasticity. Furthermore, several effects mediated by serum IGF1 are induced by physical activity while others are not (both in terms of behaviour and neural plasticity). These findings help to delimit the role of serum IGF1 as a mediator of the effects of exercise, as well as to extend the role of serum IGF1 in the brain in basal conditions. Moreover, these data reveal the complexity of the interaction between neurogenesis, behaviour, and IGF1 under different levels of physical activity.
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Affiliation(s)
- María Llorens-Martín
- Department of Molecular, Cellular, and Developmental Neurobiology, Institute Cajal, CSIC, Madrid, Spain
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13
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Growth Factors as Mediators of Exercise Actions on the Brain. Neuromolecular Med 2008; 10:99-107. [DOI: 10.1007/s12017-008-8026-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Accepted: 01/16/2008] [Indexed: 01/01/2023]
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Ahmed RL, Thomas W, Schmitz KH. Interactions between insulin, body fat, and insulin-like growth factor axis proteins. Cancer Epidemiol Biomarkers Prev 2007; 16:593-7. [PMID: 17372257 DOI: 10.1158/1055-9965.epi-06-0775] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND The etiology of hormonally related cancers, such as breast and colon, has been linked to hyperinsulinemia and insulin resistance, the insulin-like growth factor (IGF) axis, and obesity. METHODS Data from 57 women (ages 30-50 years) were used to observationally examine cross-sectional and longitudinal relations between body fat (from dual-energy X-ray absorptiometry), insulin, IGF-I, and IGF-binding proteins (IGFBP-1, IGFBP-2, and IGFBP-3). RESULTS At baseline, participants who had greater than median body fat and insulin levels, >39% and >4.5 microunits/mL, respectively, had 2.3- to 2.6-fold lower IGFBP-1 (P < 0.004) and 1.9- to 2.0-fold lower IGFBP-2 (P < 0.004) compared with other participants; IGF-I and IGFBP-3 levels did not differ by body fat or insulin levels. Over 39 weeks, a 1 microunit/mL reduction in fasting insulin was associated with a 17% increase in IGFBP-1 (P = 0.02) and a 24% increase in IGFBP-2 (P = 0.02) compared with participants who did not reduce insulin; 2.0% loss of body fat over time did not alter IGFBP-1 or IGFBP-2 levels after adjustment for insulin. IGF-I and IGFBP-3 did not change in participants who lost body fat percentage or insulin over time. CONCLUSIONS These observational associations are consistent with the hypothesis that elevated insulin and body fat are associated with decreased IGFBP-1 and IGFBP-2 levels cross-sectionally; they further imply that IGFBP-1 and IGFBP-2 levels may be altered through change in insulin over time. By contrast, no cross-sectional or longitudinal associations were noted between IGF-I and IGFBP-3 with insulin or body fat.
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Affiliation(s)
- Rehana L Ahmed
- Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, Minnesota, USA
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Ormsbee M, Clapper JA, Clapper J, Vukovich MD. Moderate changes in energy balance combined with exercise do not alter insulin-like growth factor I or insulin-like growth factor binding protein 3. Nutr Res 2006. [DOI: 10.1016/j.nutres.2006.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
STUDY DESIGN Resident's case problem. BACKGROUND A 79-year-old African American male runner sustained a left hip injury while jogging on a running track. Initial radiographs did not show any bony injuries and the patient was diagnosed with hip tendonitis. The patient was initially treated conservatively with medications and referred to a local physical therapy clinic for thermal modalities and therapeutic exercises. The patient failed to show any improvement despite a period of conservative treatment. The author examined the patient 6 months postinjury at a university physical therapy department. DIAGNOSIS The author suspected the presence of a possible fracture and the patient was referred to an orthopaedic surgeon. Subsequent radiographic imaging studies including a CT scan revealed a supra-acetabular fracture. The patient underwent a total hip arthroplasty approximately 1 year after the initial injury and has since recovered well. DISCUSSION It is not uncommon for runners or joggers to develop hip or pelvic pain, but there has been no prior report in the literature of the occurrence of an acetabular hip fracture while jogging. This resident's case problem illustrates the challenges of arriving at an accurate diagnosis in the presence of a rare fracture and the need for careful follow-up, especially among elderly individuals with cognitive deficits.
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Affiliation(s)
- Mathews Thomas
- Division of Physical Therapy, School of Allied Health Sciences, Florida A & M University, Tallahassee, FL 32307, USA.
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17
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Turgut S, Kaptanoğlu B, Emmungil G, Turgut G. Increased Plasma Levels of Growth Hormone, Insulin-Like Growth Factor (IGF)-I and IGF-Binding Protein 3 in Pregnant Rats with Exercise. TOHOKU J EXP MED 2006; 208:75-81. [PMID: 16340176 DOI: 10.1620/tjem.208.75] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Growth hormone (GH) and insulin-like growth factor-I (IGF-I) are closely related molecules. Insulin-like growth factor-binding protein-3 (IGFBP-3) is a main molecule that binds IGF-I. GH, IGF-I and IGFBP-3 have important roles in growth and development. In this study, we investigated the effects of exercise during pregnancy on maternal plasma levels of GH, IGF-I and IGFBP-3 and on fetal development. We also recorded the weights of placenta, lengths of umbilical cord, fetal body weights, fetal heights, and weights of fetal tissues. Pregnant Wistar Albino rats were divided into two groups: exercise and control groups (n = 7 for each). A treadmill exercise was performed as 20 m/min for 20 min/day, once per day for 19 days in exercise group. Blood samples were collected from pregnant rats on 0, 7th, 14th and 20th days of gestation (D) under anesthesia with intracardiac puncture, and maternal plasma levels of GH, IGF-I and IGFBP-3 were determined. Fetuses were taken with cesarean section on D20, and various parameters for fetal growth were measured. Plasma GH and IGF-I levels were elevated in exercising pregnant rats on D14 and D20, respectively, when compared to controls, and IGFBP-3 levels were increased on D14 and D20. Among the growth parameters examined, only fetal body weights and weights of fetal liver were significantly decreased in the exercise group (p < 0.01 and p < 0.05, respectively). These results indicate that maternal exercise significantly increases plasma levels of GH, IGF-I and IGFBP-3 in the late period of pregnancy but causes adverse effects on fetal growth.
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Affiliation(s)
- Sebahat Turgut
- Department of Physiology, Faculty of Medicine, Pamukkale University, Denizli, Turkey.
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18
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Bobbert T, Brechtel L, Mai K, Otto B, Maser-Gluth C, Pfeiffer AFH, Spranger J, Diederich S. Adaptation of the hypothalamic-pituitary hormones during intensive endurance training. Clin Endocrinol (Oxf) 2005; 63:530-6. [PMID: 16268805 DOI: 10.1111/j.1365-2265.2005.02377.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Physical activity leads to changes in the hypothalamic-pituitary hormonal system. However, acute and long-term adaptations have not yet been precisely characterized. In this study, the changes of the hormonal system as a result of marathon training and running a marathon were examined. In particular, we focused on adaptations of the hypothalamic-pituitary-adrenocortical (HPA) axis, regarding the activation or inactivation of cortisol to cortisone by the 11beta-hydroxysteroid-dehydrogenase system (11beta-HSD). DESIGN Patient measurements: 8 healthy women and 11 healthy men volunteered for this study. Blood samples, 24-h urine and a dexamethasone suppression test were analysed for metabolic and hormonal parameters at five different dates 12 weeks around a marathon. RESULTS Cortisol and ACTH values decreased significantly 2 days after the marathon, whereas the activity of the whole body 11beta-HSD-1 was up-regulated. An increased suppression of cortisol levels was observed in the dexamethasone suppression test after 6 weeks of reduced training levels. Ghrelin was elevated 2 days after the marathon. Only minor changes in the other hypothalamic-pituitary-hormonal axes could be observed. However, the free androgen index increased significantly after 6 weeks of reduced training. CONCLUSIONS The HPA system appeared to become chronically activated by continuous physical training and therefore less sensitive to the dexamethasone suppression test. The acute stress of the marathon led to a central exhaustion of the HPA system with a paracrine counteraction by the activation of the 11beta-HSD system. Changes in the other hypothalamic-pituitary hormonal axes were the result of long-term differences in training levels and were not altered by the marathon.
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Affiliation(s)
- T Bobbert
- Department of Endocrinology, Diabetes and Nutrition, Charité University Medicine Berlin, Campus Benjamin Franklin, Germany.
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19
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Mejri S, Bchir F, Ben Rayana MC, Ben Hamida J, Ben Slama C. Effect of training on GH and IGF-1 responses to a submaximal exercise in football players. Eur J Appl Physiol 2005; 95:496-503. [PMID: 16151829 DOI: 10.1007/s00421-005-0007-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2005] [Indexed: 10/25/2022]
Abstract
To study the effects of regular football training on basal and exercise induced levels of growth hormone (GH) and insulin-like growth factor (IGF-1), 13 young football players were investigated by a submaximal exercise at the beginning of the sporting season in October (S1), at the middle of the season in January (S2) and at the end in May (S3). At each session, an exercise test on an ergogycle was performed for 25 min, beginning with an incremental exercise to reach 90% of theoretical maximal heart, which was maintained for the last 10 min of the test. Venous blood samples were collected at rest, at the end of the exercise and at 30 and 60 min during the recovery period. Plasma lactate and glucose concentrations increased during exercise with no difference found between sessions. GH level increased with exercise at each session but the response was significantly higher in S1 than in S2 and S3 (P<0.01). The GH area under the curve decreased significantly all along the football season (P<0.01); the IGF-1 level did not significantly change during exercise nor with training. Basal insulin-like growth factor binding protein-3 (IGFBP3) remained stable during the three sessions. Football training decreased significantly the exercise-stimulated GH levels all along the football season but did not have any significant effect on IGF-1 levels or on basal IGFBP3 levels.
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Affiliation(s)
- S Mejri
- Service d'Endocrinologie et Métabolisme, Institut National de Nutrition, 11, Rue Djebel-Lakhdar-Bab Saâdoun, 1007, Tunis, Tunisie
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20
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Urso M, Cosmas A, Singh MF, Manfredi T. Immunogold labeling of insulin growth factor-I receptors in elderly human skeletal muscle. SCANNING 2005; 27:208-12. [PMID: 16089305 DOI: 10.1002/sca.4950270408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Age-associated muscle wasting, or sarcopenia, can be delayed or reversed with interventions, including exercise and pharmaceutical agents. Mapping morphometric changes in the skeletal muscle insulin growth factor 1 receptor can provide valuable information regarding mechanisms controlling muscle protein metabolism. Immunocolloidal gold labeling is a powerful immunocytochemistry procedure for detecting antigens at the ultrastructural level, providing plausible biological markers of cell and tissue adaptations to stimuli. The intent here was to employ immunogold labeling to identify, localize, and quantify the insulin growth factor receptor-I (IGF-IR) in elderly human skeletal muscle. Needle biopsy specimens of the leg vastus lateralis muscle were fixed with 1% glutaraldehyde and 4% paraformaldehyde, dehydrated, and embedded in LR white resin. Pilot experiments were carried out to establish optimal dilutions of primary and secondary antibodies and to employ controls to establish staining specificity. The 6 nm gold particles were first evident when viewed at transmission electron microscopy (TEM) magnifications at 54,000x and clearest at 71,000x. Consistencies were noted in the staining patterns, with the majority of particles lying in proximity to the myofilaments. Gold particles were also found randomly along the outer membrane of the sarcolemma and the mitochondrial membranes. National Institutes of Health (NIH) Image 1.55 version software was used to measure receptor density (NIH, Bethesda, Md., USA). It appears that immunogold labeling of postembedded tissue samples is a sensitive method for detecting IGF-I receptors at the ultrastructural level.
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Affiliation(s)
- Maria Urso
- Exercise Science, University of Massachusetts, Amherst, Massachusetts, USA
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21
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Mejri S, Bchir F, Koubâa D, Ben Slama C. Réponses de GH, IGF-1 et IGF-BP3 à un exercice submaximal : différences entre sujets entraînés et sédentaires. Sci Sports 2004. [DOI: 10.1016/s0765-1597(03)00168-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Affiliation(s)
- Anders Juul
- Department of Growth and Reproduction, University of Copenhagen, Blegdamsvej 9 Rigshopitalet, Section 5064, Copenhagen 2100, Denmark.
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23
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Manetta J, Brun JF, Fedou C, Maïmoun L, Prefaut C, Mercier J. Serum levels of insulin-like growth factor-I (IGF-I), and IGF-binding proteins-1 and -3 in middle-aged and young athletes versus sedentary men: relationship with glucose disposal. Metabolism 2003; 52:821-6. [PMID: 12870155 DOI: 10.1016/s0026-0495(03)00096-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The goal of this study was to characterize the respective effects of aging and endurance training on serum insulin-like growth factor I (IGF-I), as well as IGF-binding proteins (IGFBP)-1 and -3 in relationship with glucose disposal. Thirty-two subjects (16 middle-aged men: 8 cyclists and 8 sedentary men; and 16 young men: 8 cyclists and 8 sedentary men) were compared in this study. Insulin sensitivity (SI) and glucose effectiveness (Sg) were assessed by the minimal model. Endurance training increased SI, Sg, and IGFBP-1 and -3 in both age groups (P<.05), but the older group showed a greater increase in SI and IGFBP-1 than the younger group (P<.05). IGF-I was increased only in the middle-aged trained men (P<.05). An effect of aging was found in the sedentary subjects, who presented lower IGF-I and SI (P<.05) when older. This effect disappeared with training since IGF-I and SI were nearly identical in young and middle-aged trained subjects. SI was correlated with IGFBP-1 (P<.01). These data suggest that (1) endurance training increases SI, Sg, and IGFBP-1 and -3 in men and, for SI and IGFBP-1, this increase becomes more pronounced with age; (2) endurance training may attenuate the aged-related decline in SI and IGF-I; and (3) IGFBP-1 may protect against the risk of hypoglycemia by counteracting the hypoglycemic effect of IGF-I in such situations of high SI.
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Affiliation(s)
- J Manetta
- Metabolic Unit, Service Central de Physiologie Clinique, Centre d'Exploration et de Réadaptation des Anomalies Métaboliques et Musculaires, Hôpital Lapeyronie, Monpellier, France
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Wideman L, Weltman JY, Hartman ML, Veldhuis JD, Weltman A. Growth hormone release during acute and chronic aerobic and resistance exercise: recent findings. Sports Med 2003; 32:987-1004. [PMID: 12457419 DOI: 10.2165/00007256-200232150-00003] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Exercise is a potent physiological stimulus for growth hormone (GH) secretion, and both aerobic and resistance exercise result in significant, acute increases in GH secretion. Contrary to previous suggestions that exercise-induced GH release requires that a "threshold" intensity be attained, recent research from our laboratory has shown that regardless of age or gender, there is a linear relationship between the magnitude of the acute increase in GH release and exercise intensity. The magnitude of GH release is greater in young women than in young men and is reduced by 4-7-fold in older individuals compared with younger individuals. Following the increase in GH secretion associated with a bout of aerobic exercise, GH release transiently decreases. As a result, 24-hour integrated GH concentrations are not usually elevated by a single bout of exercise. However, repeated bouts of aerobic exercise within a 24-hour period result in increased 24-hour integrated GH concentrations. Because the GH response to acute resistance exercise is dependent on the work-rest interval and the load and frequency of the resistance exercise used, the ability to equate intensity across different resistance exercise protocols is desirable. This has proved to be a difficult task. Problems with maintaining patent intravenous catheters have resulted in a lack of studies investigating alterations in acute and 24-hour GH pulsatile secretion in response to resistance exercise. However, research using varied resistance protocols and sampling techniques has reported acute increases in GH release similar to those observed with aerobic exercise. In young women, chronic aerobic training at an intensity greater than the lactate threshold resulted in a 2-fold increase in 24-hour GH release. The time line of adaptation and the mechanism(s) by which this training effect occurs are still elusive. Unfortunately, there are few studies investigating the effects of chronic resistance training on 24-hour GH release. The decrease in GH secretion observed in individuals who are older or have obesity is associated with many deleterious health effects, although a cause and effect relationship has not been established. While exercise interventions may not restore GH secretion to levels observed in young, healthy individuals, exercise is a robust stimulus of GH secretion. The combination of exercise and administration of oral GH secretagogues may result in greater GH secretion than exercise alone in individuals who are older or have obesity. Whether such interventions would result in favourable clinical outcomes remains to be established.
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Affiliation(s)
- Laurie Wideman
- Department of Exercise and Sport Science, University of North Carolina-Greensboro, Rm. 237E Health and Human Performance Building, Greensboro, NC 27410, USA.
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25
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Rosendal L, Langberg H, Flyvbjerg A, Frystyk J, Ørskov H, Kjaer M. Physical capacity influences the response of insulin-like growth factor and its binding proteins to training. J Appl Physiol (1985) 2002; 93:1669-75. [PMID: 12381752 DOI: 10.1152/japplphysiol.00145.2002] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The influence of initial training status on the response of circulating insulin-like growth factor (IGF) and its binding proteins (IGFBP) to prolonged physical training was studied in young men. It was hypothesized that highly standardized training would result in more extensive changes in the circulating IGF system in untrained subjects because of lower fitness level. Seven untrained (UT) and 12 well-trained (WT) individuals performed 11 wk of intense physical training (2-4 h daily). Fasting serum samples were analyzed for total and free IGF-I and -II, for IGFBP-1 to -4, as well as for IGFBP-3 proteolysis. Eleven weeks of physical training resulted in decreased levels of total IGF-I, free IGF-I, and IGFBP-4 in both the UT and WT groups. In the UT group, IGFBP-2 increased, IGFBP-3 decreased [from 4,255 +/- 410 (baseline) to 3,896 +/- 465 (SD) microg/l (week 4); P < 0.05], and IGFBP-3 proteolysis increased [from 28 +/- 8% (baseline) to 37 +/- 7% (week 4) and 39 +/- 12% (week 11); P < 0.05], whereas no significant changes were found in the WT group. In conclusion, intense physical training results in a marked influence on the IGF system and its binding proteins with generally more extensive changes seen in the untrained individuals. Also, prolonged physical training resulted in increased IGFBP-3 proteolysis in previously untrained individuals only, indicating that intense physical training affects trained and untrained individuals differently.
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Affiliation(s)
- Lars Rosendal
- Sports Medicine Research Unit and Copenhagen Muscle Research Centre, Bispebjerg Hospital, DK-2400 Copenhagen, Denmark.
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26
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Manetta J, Brun JF, Maimoun L, Callis A, Préfaut C, Mercier J. Effect of training on the GH/IGF-I axis during exercise in middle-aged men: relationship to glucose homeostasis. Am J Physiol Endocrinol Metab 2002; 283:E929-36. [PMID: 12376319 DOI: 10.1152/ajpendo.00539.2001] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to compare circulating levels of growth hormone (GH), IGF-I, and IGF-binding protein (IGFBP)-1 and IGFBP-3 in response to a long-duration endurance exercise in trained vs. sedentary middle-aged males and to determine whether a relationship with glucose homeostasis exists. Seven trained men (Tr) were compared with seven age-matched sedentary men (Sed) during two trials of 60 min of cycling exercise performed below (-VT) and above (+VT) the ventilatory threshold. Insulin sensitivity (S(I)) was higher in Tr than in Sed (P < 0.001). Basal GH, IGF-I, and IGFBP-1 and -3 were higher in Tr (P < 0.05). During +VT, Tr had a threefold higher GH response, whereas their blood glucose level was better maintained (P < 0.05). Basal IGFBP-1 was correlated with S(I) (P < 0.01). These data indicate that endurance training in middle-aged men increased the activity of the GH/IGF-I system and improved glucoregulation both at rest and during high-intensity endurance exercise.
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Affiliation(s)
- Jérôme Manetta
- Service Central de Physiologie Clinique: Centre d'Exploration et de Réadaptation des Anomalies Métaboliques et Musculaires, hôpital Lapeyronie, 34295 Montpellier, France.
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28
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Abstract
This review summarizes the interactions between growth hormone (GH) and exercise. Exercise has profound effects upon the GH-insulin-like growth factor I axis per se. In addition, there is increasing evidence that such physiological perturbations might be influential in the performance responses to repeated training. However, the ergogenic effects of systemic administration of recombinant human GH by athletes and bodybuilders remain unproven. What is certain is that the prevalence of GH abuse by sportspeople will increase, not least because it is currently undetectable. The frequent and potentially severe side-effects associated with such 'doping' will be of increasing relevance to endocrinologists.
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Affiliation(s)
- P J Jenkins
- Department of Endocrinology, St Bartholomew's Hospital, London, UK.
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Abstract
This review summarizes the interactions between GH and exercise. Not only does exercise have profound effects upon the GH/IGF-I axis per se, but there is increasing evidence that such physiological perturbations might be influential in the performance responses to repeated training. However, the effects of systemic administration of rGH in restoring exercise capability and muscle strength in GH deficient adults and the ergogenic benefits of GH doping amongst athletes remain unproven. What is certain is that these issues will be of increasing relevance to clinical endocrinologists.
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Affiliation(s)
- P J Jenkins
- Department of Endocrinology, St Bartholomew's Hospital, London, UK
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30
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