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Schilbach K, Bidlingmaier M. Growth hormone binding protein - physiological and analytical aspects. Best Pract Res Clin Endocrinol Metab 2015; 29:671-83. [PMID: 26522453 DOI: 10.1016/j.beem.2015.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A significant proportion of total circulating growth hormone (GH) is bound to a high affinity growth hormone binding protein (GHBP). Several low affinity binding proteins have also been described. Significant differences between species exist with respect to origin and regulation of GHBP, but generally it resembles the extracellular domain of the GH receptor. Concentrations are associated with GH status, body composition and other factors. Although the clinical relevance of GHBP is not fully understood it is suggested that concentrations indirectly reflect GH receptor status. This is supported by cases of Laron's syndrome where a molecular defect in the extracellular domain of the GH receptor is associated with low or unmeasurable GHBP concentrations. Methods to measure GHBP have evolved from chromatographic, activity based procedures to direct immunoassays. In clinical practice, measurement of GHBP can be helpful to differentiate between GH deficiency and GH insensitivity, particularly if GHBP is absent.
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Affiliation(s)
- Katharina Schilbach
- Endocrine Laboratory, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Ziemssenstr. 1, 80336, Munich, Germany.
| | - Martin Bidlingmaier
- Endocrine Laboratory, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Ziemssenstr. 1, 80336, Munich, Germany.
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Vestergaard PF, Vendelbo MH, Pedersen SB, Juul A, Ringgard S, Møller N, Jessen N, Jørgensen JOL. GH signaling in skeletal muscle and adipose tissue in healthy human subjects: impact of gender and age. Eur J Endocrinol 2014; 171:623-31. [PMID: 25163724 DOI: 10.1530/eje-14-0538] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE The mechanisms underlying the impact of age and gender on the GH-IGF1 axis remain unclear. We tested the hypothesis that age and gender have impacts on GH signaling in human subjects in vivo. DESIGN A total of 20 healthy non-obese adults ('young group'<30 years (5F/5M) and 'old group'>60 years (5F/5M)) were studied after: i) an i.v. GH bolus (0.5 mg) and ii) saline. METHODS Muscle and fat biopsies were obtained after 30 and 120 min. Total and phosphorylated STAT5B proteins, gene expression of IGF1, SOCS1, SOCS2, SOCS3 and CISH, body composition, VO2max, and muscle strength were measured. RESULTS In the GH-unstimulated state, women displayed significantly elevated levels of CISH mRNA in muscle (P=0.002) and fat (P=0.05) and reduced levels of IGF1 mRNA in fat. Phosphorylated STAT5B (pSTAT5b) was maximally increased in all subjects 30 min after GH exposure and more pronounced in women when compared with men (P=0.01). IGF1, SOCS1, SOCS2, SOCS3, and CISH mRNA expression increased significantly in muscle after 120 min in all subjects with no impact of age and gender. GH-induced pSTAT5b correlated inversely with lean body mass (LBM; r=-0.56, P=0.01) and positively with the CISH mRNA response (r=0.533, P=0.05). CONCLUSION i) GH signaling in muscle and fat after a single GH bolus in healthy human subjects is age independent, ii) we hypothesize that constitutive overexpression of CISH may contribute to the relative GH resistance in women, and iii) experimental studies on the impact of sex steroid administration and physical training on GH signaling in human subjects in vivo are required.
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Affiliation(s)
- Poul F Vestergaard
- The Medical Research LaboratoriesDepartment of Endocrinology and Internal Medicine, Faculty of Health Sciences, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus University, Nørrebrogade 44, DK-8000 Aarhus C, DenmarkDepartment of Growth and ReproductionUniversity Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen Ø, DenmarkDepartment of Clinical MedicineMR Research Centre Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus N, Denmark
| | - Mikkel H Vendelbo
- The Medical Research LaboratoriesDepartment of Endocrinology and Internal Medicine, Faculty of Health Sciences, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus University, Nørrebrogade 44, DK-8000 Aarhus C, DenmarkDepartment of Growth and ReproductionUniversity Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen Ø, DenmarkDepartment of Clinical MedicineMR Research Centre Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus N, Denmark
| | - Steen B Pedersen
- The Medical Research LaboratoriesDepartment of Endocrinology and Internal Medicine, Faculty of Health Sciences, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus University, Nørrebrogade 44, DK-8000 Aarhus C, DenmarkDepartment of Growth and ReproductionUniversity Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen Ø, DenmarkDepartment of Clinical MedicineMR Research Centre Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus N, Denmark
| | - Anders Juul
- The Medical Research LaboratoriesDepartment of Endocrinology and Internal Medicine, Faculty of Health Sciences, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus University, Nørrebrogade 44, DK-8000 Aarhus C, DenmarkDepartment of Growth and ReproductionUniversity Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen Ø, DenmarkDepartment of Clinical MedicineMR Research Centre Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus N, Denmark
| | - Steffen Ringgard
- The Medical Research LaboratoriesDepartment of Endocrinology and Internal Medicine, Faculty of Health Sciences, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus University, Nørrebrogade 44, DK-8000 Aarhus C, DenmarkDepartment of Growth and ReproductionUniversity Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen Ø, DenmarkDepartment of Clinical MedicineMR Research Centre Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus N, Denmark
| | - Niels Møller
- The Medical Research LaboratoriesDepartment of Endocrinology and Internal Medicine, Faculty of Health Sciences, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus University, Nørrebrogade 44, DK-8000 Aarhus C, DenmarkDepartment of Growth and ReproductionUniversity Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen Ø, DenmarkDepartment of Clinical MedicineMR Research Centre Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus N, Denmark
| | - Niels Jessen
- The Medical Research LaboratoriesDepartment of Endocrinology and Internal Medicine, Faculty of Health Sciences, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus University, Nørrebrogade 44, DK-8000 Aarhus C, DenmarkDepartment of Growth and ReproductionUniversity Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen Ø, DenmarkDepartment of Clinical MedicineMR Research Centre Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus N, Denmark
| | - Jens O L Jørgensen
- The Medical Research LaboratoriesDepartment of Endocrinology and Internal Medicine, Faculty of Health Sciences, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus University, Nørrebrogade 44, DK-8000 Aarhus C, DenmarkDepartment of Growth and ReproductionUniversity Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen Ø, DenmarkDepartment of Clinical MedicineMR Research Centre Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus N, Denmark
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Brick DJ, Gerweck AV, Meenaghan E, Lawson EA, Misra M, Fazeli P, Johnson W, Klibanski A, Miller KK. Determinants of IGF1 and GH across the weight spectrum: from anorexia nervosa to obesity. Eur J Endocrinol 2010; 163:185-91. [PMID: 20501597 PMCID: PMC2953770 DOI: 10.1530/eje-10-0365] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
CONTEXT Chronic starvation is characterized by GH resistance, and obesity is characterized by decreased GH secretion. In both extremes, IGF1 levels may be low and androgen levels may be abnormal. OBJECTIVE To investigate the determinants of IGF1 and GH across the weight spectrum in women. DESIGN Cross-sectional study. SETTING Clinical research center. STUDY PARTICIPANTS In total, 32 women had participated in the study: 11 women with anorexia nervosa (AN), 11 normal-weight women, and 10 obese women of comparable mean age. INTERVENTION None. MAIN OUTCOME MEASURES Pooled hourly overnight serum samples assayed for IGF1, GH, estradiol (E(2)), testosterone, SHBG, insulin, free fatty acids, and trunk fat. RESULTS Free testosterone was higher in obese women and lower in women with AN than in normal-weight women, and was the only independent (and positive) predictor of IGF1 levels, accounting for 14% of the variability (P=0.032) in the group as a whole. This relationship was stronger when obese women were excluded, with free testosterone accounting for 36% of the variability (P=0.003). Trunk fat accounted for 49% of the variability (P<0.0001) of GH, with an additional 7% of the variability attributable to E(2) (P=0.042) in the group as a whole, but was not a significant determinant of GH secretion when obese women were excluded. CONCLUSIONS Free testosterone is a significant determinant of IGF1 levels in women across the body weight spectrum. In contrast, GH secretion is differentially regulated at the extremes of the weight spectrum.
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Affiliation(s)
- D J Brick
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
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Gleeson HK, Shalet SM. Effect of aromatizable and unaromatizable androgen replacement in hypogonadal men on GH responsiveness. Clin Endocrinol (Oxf) 2009; 70:109-15. [PMID: 18549466 DOI: 10.1111/j.1365-2265.2008.03312.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Although studies have clearly demonstrated that oestrogen replacement affects GH responsiveness by causing relative GH resistance, the effect of androgen replacement is unknown. Circumstantial evidence only suggests that androgen replacement may increase GH sensitivity and/or responsiveness. To examine the impact of androgens on GH responsiveness, hypogonadal men underwent the IGF-1 generation test in the unreplaced state, replaced with testosterone (T) and also replaced with dihydrotestosterone (DHT), its nonaromatizable metabolite. DESIGN AND PATIENTS Twelve hypogonadal men with a normal GH axis were recruited. Each subject in random order had 4 weeks off T (NoRx), 4 weeks on T gel (TG) and 4 weeks on DHT gel (DHTG) applied daily, with 1 week washout between each preparation. An IGF-1 generation test using a subcutaneous injection of 7 mg of GH was performed at the end of each of these 4-week phases. MEASUREMENTS Serum GHBP, total and free IGF-1, IGFBP-3 and acid-labile subunit (ALS) levels were measured at baseline and 24 h (peak) after GH administration. RESULTS Despite a decrease in GHBP during the TG and DHTG phases, there were no observed differences in baseline, peak or increment (peak - baseline) total or free IGF-1 between the NoRx, TG or DHTG phases. CONCLUSIONS There is no evidence of fluctuation in GH responsiveness in hypogonadal men, untreated or replaced with T or DHT alone. This implies that the increased level of oestradiol as a consequence of T replacement in hypogonadal men does not impact significantly on GH responsiveness, nor is there evidence of an androgen effect with elevated DHT levels as a consequence of either T or DHT replacement.
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Affiliation(s)
- Helena K Gleeson
- Department of Endocrinology, Christie Hospital, Wilmslow Road, Withington, Manchester, M20 4BX, UK.
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Münzer T, Rosen CJ, Harman SM, Pabst KM, St Clair C, Sorkin JD, Blackman MR. Effects of GH and/or sex steroids on circulating IGF-I and IGFBPs in healthy, aged women and men. Am J Physiol Endocrinol Metab 2006; 290:E1006-13. [PMID: 16390864 DOI: 10.1152/ajpendo.00166.2005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Circulating GH, IGF-I, IGFBP-3, and sex steroid concentrations decrease with age. GH or sex steroid treatment increases IGFBP-3, but little is known regarding the effects of these hormones on other IGFBPs. We assessed the effects of 26 wk of administration of GH, sex steroids, or GH + sex steroids on AM levels of IGF-I, IGFBPs 1-5, insulin, glucose, and osteocalcin and 2-h urinary excretion of deoxypyridinolline (DPD) cross-links in 53 women and 71 men aged 65-88 yr. Before treatment, in women and men, IGF-I was directly related to IGFBP-3 (P < 0.001 and P < 0.0001) and IGFBP-1 to IGFBP-2 (P = 0.0001). In women, IGFBP-1 was inversely related to insulin (P < 0.0005) and glucose (P < 0.005) and IGFBP-4 to osteocalcin (P < 0.01). IGFBP-4 and IGFBP-5 were not significantly related to DPD cross-links. GH and/or sex steroid increased IGF-I levels in both sexes, with higher concentrations in men (P < 0.001). In women, the IGF-I increment after GH was attenuated by hormone replacement therapy (HRT) coadministration (P < 0.05). Hormone administration also increased IGFBP-3. IGFBP-1 was unaffected by GH + sex steroids, whereas GH decreased IGFBP-2 by 15% in men (P < 0.05). Hormone administration did not change IGFBP-4, whereas in men IGFBP-5 increased by 20% after GH (P < 0.05) and 56% after GH + testosterone (P = 0.0003). These data demonstrate sexually dimorphic IGFBP responses to GH. Additionally, HRT attenuated or prevented GH-mediated increases in IGF-I and IGFBP-3. Whether GH and/or sex steroid administration alters local tissue production of IGFBPs and whether the latter influence autocrine or paracrine actions of IGF-I remain to be determined.
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Affiliation(s)
- Thomas Münzer
- Endocrine Section, Laboratory of Clinical Investigations, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
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Fisker S. Physiology and pathophysiology of growth hormone-binding protein: methodological and clinical aspects. Growth Horm IGF Res 2006; 16:1-28. [PMID: 16359897 DOI: 10.1016/j.ghir.2005.11.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Revised: 10/01/2005] [Accepted: 11/01/2005] [Indexed: 11/20/2022]
Abstract
Circulating GH is partly bound to a high-affinity binding protein (GHBP), which in humans is derived from cleavage of the extracellular domain of the GH receptor. The precise biological function GHBP is unknown, although a regulation of GH bioactivity appears plausible. GHBP levels are determined by GH secretory status, body composition, age, and sex hormones, but the cause-effect relationships remain unclarified. In addition to the possible in vivo significance of GHBP, the interaction between GH and GHBP has methodological implications for both GH and GHBP assays. The present review concentrates on methodological aspects of GHBP measurements, GHBP levels in certain clinical conditions with a special emphasis on disturbances in the GH-IGF axis, and discusses the possible relationship between plasma GHBP and GH receptor status in peripheral tissues.
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Affiliation(s)
- Sanne Fisker
- Medical Department M (Endocrinology and Diabetes), Aarhus University Hospital, Aarhus Sygehus, Nørrebrogade 44, DK-8000 Aarhus C, Denmark.
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Veldhuis JD, Roemmich JN, Richmond EJ, Rogol AD, Lovejoy JC, Sheffield-Moore M, Mauras N, Bowers CY. Endocrine control of body composition in infancy, childhood, and puberty. Endocr Rev 2005; 26:114-46. [PMID: 15689575 DOI: 10.1210/er.2003-0038] [Citation(s) in RCA: 273] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Body composition exhibits marked variations across the early human lifetime. The precise physiological mechanisms that drive such developmental adaptations are difficult to establish. This clinical challenge reflects an array of potentially confounding factors, such as marked intersubject differences in tissue compartments; the incremental nature of longitudinal intrasubject variations in body composition; technical limitations in quantitating the unobserved mass of mineral, fat, water, and muscle ad seriatim; and the multifold contributions of genetic, dietary, environmental, hormonal, nutritional, and behavioral signals to physical and sexual maturation. From an endocrine perspective (reviewed here), gonadal sex steroids and GH/IGF-I constitute prime determinants of evolving body composition. The present critical review examines hormonal regulation of body composition in infancy, childhood, and puberty.
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Affiliation(s)
- Johannes D Veldhuis
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Mayo Medical and Graduate Schools of Medicine, General Clinical Research Center, Mayo Clinic, Rochester, Minnesota 55905, USA.
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Micić D, Sumarac-Dumanović M, Macut D, Kendereski A, Zoric S, Popović V, Cvijović G, Dieguez C, Casanueva FF. Growth-hormone response to combined stimulation with GHRH plus GH-releasing peptide-6 in obese patients with polycystic ovary syndrome before and after short-term fasting. J Endocrinol Invest 2003; 26:333-40. [PMID: 12841541 DOI: 10.1007/bf03345181] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Controversial data were reported on GH response to different provocative stimuli in obese patients with polycystic ovary syndrome (PCOS). The objective of our study was to assess the effect of short-term fasting on GH response to combined stimulus with GHRH+GH-releasing peptide-6 (GHRP-6) in obese patients with PCOS and possible relation with leptin and insulin changes during fasting. Twelve obese PCOS women and nine obese control women participated in 3-day fasting. GH response, IGF-I, insulin and leptin were measured after GHRH+ GHRP-6, before and after short-term fasting. Obese PCOS patients had significantly greater GH peak after GHRH+GHRP-6 before fasting. Enhanced response to GH stimulation was found after fasting without substantial differences between obese PCOS and obese controls. Insulin and leptin significantly decreased, while insulin sensitivity significantly improved in both groups during fasting. In conclusion, obese PCOS patients have peculiar type of GH response to GHRH+GHRP-6 before fasting, possibly due to enhanced sensitivity of somatotrophs. Observed changes in insulin and leptin may participate in modulation of enhanced GH response after short-term fasting to GHRH+GHRP-6 in PCOS and obese controls.
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Affiliation(s)
- D Micić
- Institute of Endocrinology, Diabetes and Diseases of Metabolism, Beograd, Yugoslavia.
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