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Paragliola RM, Carrozza C, Corsello SM, Salvatori R. The biochemical diagnosis of acromegaly: revising the role of measurement of IGF-I and GH after glucose load in 5 questions. Expert Rev Endocrinol Metab 2022; 17:205-224. [PMID: 35485763 DOI: 10.1080/17446651.2022.2069558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 04/20/2022] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Acromegaly is a rare disorder characterized by the excessive secretion of growth hormone (GH), mostly caused by pituitary adenomas. While in full-blown cases the diagnosis is easy to establish, milder cases are more challenging. Additionally, establishing whether full cure after surgery is reached may be difficult. AREAS COVERED In this article, we will review the challenges posed by the variability in measurements of GH and its main effector insulin-like growth factor I (IGF-I) due to both biological changes, co-morbidities, and assays variability. EXPERT OPINION Interpretation of GH and IGF-I assays is important in establishing an early diagnosis of acromegaly, in avoiding misdiagnosis, and in establishing if cure is achieved by surgery. Physicians should be familiar with the variables that affect measurements of these 2 hormones, and with the performance of the assays available in their practice.
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Affiliation(s)
- Rosa Maria Paragliola
- Unit of Endocrinology, Department of Translational Medicine and Surgery - Universita' Cattolica del Sacro Cuore, Fondazione Policlinico "Gemelli", IRCCS, Rome, Italy
| | - Cinzia Carrozza
- Unit of Chemistry, Biochemistry and Clinical Molecular Biology - Università Cattolica Del Sacro Cuore, Fondazione Policlinico "Gemelli," IRCCS, Rome, Italy
| | - Salvatore M Corsello
- Unit of Endocrinology, Department of Translational Medicine and Surgery - Universita' Cattolica del Sacro Cuore, Fondazione Policlinico "Gemelli", IRCCS, Rome, Italy
- UniCamillus-Saint Camillus International University of Health Sciences, Rome, Italy
| | - Roberto Salvatori
- Division of Endocrinology Diabetes and Metabolism and Pituitary Center, Johns Hopkins University, Baltimore MD, USA
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Sakata K, Nagata Y, Takeshige N, Kikuchi J, Shikata M, Ashida K, Nomura M, Morioka M. Early postoperative prediction of both disease remission and long-term disease control in acromegaly using the oral glucose tolerance test. Hormones (Athens) 2021; 20:515-526. [PMID: 33738782 DOI: 10.1007/s42000-021-00281-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 03/07/2021] [Indexed: 12/18/2022]
Abstract
PURPOSE Transsphenoidal surgery (TSS) is the cornerstone of acromegaly treatment. Two biochemical parameters, growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels, sometimes diverge postoperatively; however, it is important to maintain disease control without further treatment, regardless of whether these parameters converge. This study investigated whether remission and long-term disease control could be predicted using early postoperative GH and IGF-1 levels. METHODS We reviewed 36 consecutive surgically treated patients with acromegaly. IGF-1 levels and minimum GH levels during an oral glucose tolerance test (OGTT) were evaluated at 2 weeks, as well as at 3 months postoperatively. After comparison between the remission and nonremission groups, we analyzed whether early postoperative parameters could predict remission and long-term disease control. RESULTS Twenty-five patients (69.4%, Group A) achieved remission within 1 year postoperatively. Of the remaining patients (median follow-up period, 53 months), seven (19.5%, Group B) maintained normal IGF-1 levels without treatment, whereas four (11.1%, Group C) required additional treatment. GH levels <1.5 ng/mL measured on the morning after surgery and nadir GH levels <0.7 ng/mL during the OGTT conducted at 2 weeks postoperatively were predictive of remission, with the latter demonstrating 95.2% sensitivity and 100% specificity. All group C patients had nadir GH levels ≥0.7 ng/mL during the OGTT and IGF-1 levels ≥SD +3 at 2 weeks postoperatively. CONCLUSION Early postoperative nadir GH levels during the OGTT and IGF-1 levels at 2 weeks postoperatively demonstrated excellent predictive value for both endocrinological remission and the necessity for additional treatment.
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Affiliation(s)
- Kiyohiko Sakata
- Department of Neurosurgery, Kurume University School of Medicine, Fukuoka, Japan.
| | - Yui Nagata
- Department of Neurosurgery, Kurume University School of Medicine, Fukuoka, Japan
| | - Nobuyuki Takeshige
- Department of Neurosurgery, Kurume University School of Medicine, Fukuoka, Japan
| | - Jin Kikuchi
- Department of Neurosurgery, Kurume University School of Medicine, Fukuoka, Japan
| | - Masato Shikata
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, Fukuoka, Japan
| | - Kenji Ashida
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, Fukuoka, Japan
| | - Masatoshi Nomura
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, Fukuoka, Japan
| | - Motohiro Morioka
- Department of Neurosurgery, Kurume University School of Medicine, Fukuoka, Japan
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Dal J, Skov BG, Andersen M, Feldt-Rasmussen U, Feltoft CL, Karmisholt J, Nielsen EH, Dekkers OM, Jørgensen JOL. Sex differences in acromegaly at diagnosis: A nationwide cohort study and meta-analysis of the literature. Clin Endocrinol (Oxf) 2021; 94:625-635. [PMID: 33306249 DOI: 10.1111/cen.14392] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/06/2020] [Accepted: 12/03/2020] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Data on sex differences in acromegaly at the time of diagnosis vary considerably between studies. DESIGN A nationwide cohort study including all incident cases of acromegaly (1978-2010, n = 596) and a meta-analysis on sex differences in active acromegaly (40 studies) were performed. METHOD Sex-dependent differences in prevalence, age at diagnosis, diagnostic delay, pituitary adenoma size, insulin-like growth factor 1 (IGF-I) and growth hormone (GH) concentrations were estimated. RESULTS The cohort study identified a balanced gender distribution (49.6% females) and a comparable age (years) at diagnosis (48.2 CI95% 46.5-49.8 (males) vs. 47.2 CI95% 45.5-48.9 (females), p = 0.4). The incidence rate significantly increased during the study period (R2 = 0.42, p < 0.01) and the gender ratio (F/M) changed from female predominance to an even ratio (SR: 1.4 vs. 0.9, p = 0.03). IGF-ISDS was significantly lower in females compared to males, whereas neither nadir GH nor pituitary adenoma size differed between males and females. In the meta-analysis, the weighted percentage female was 53.3% (CI95% 51.5-55.2) with considerable heterogeneity (I2 = 85%) among the studies. The mean age difference at diagnosis between genders was 3.1 years (CI95% 1.9-4.4), and the diagnostic delay was longer in females by 0.9 years (CI95% -0.4 to 2.1). Serum IGF-I levels were significantly lower in female patients, whereas nadir GH, and pituitary adenoma size were comparable. CONCLUSION There are only a minor sex differences in the epidemiology of acromegaly at the time of diagnosis except that female patients are slightly older and exhibit lower IGF-I concentrations and a longer diagnostic delay.
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Affiliation(s)
- Jakob Dal
- Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark
- Steno Diabetes Center North Jutland, Aalborg, Denmark
| | - Benedikte G Skov
- Department of Endocrinology, Aarhus University Hospital, Aarhus C, Denmark
| | - Marianne Andersen
- Department of Endocrinology, Odense University Hospital, Odense, Denmark
| | - Ulla Feldt-Rasmussen
- Department of Endocrinology and Metabolism, National University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Claus L Feltoft
- Department of Endocrinology, Herlev University Hospital, Herlev, Denmark
| | - Jesper Karmisholt
- Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark
- Clinical Institute, Aalborg University, Aalborg, Denmark
| | - Eigil H Nielsen
- Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark
| | - Olaf M Dekkers
- Department of Clinical Epidemiolgy and Metabolism, Leiden University Medical Centre, Leiden, The Netherlands
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Hage M, Kamenický P, Chanson P. Growth Hormone Response to Oral Glucose Load: From Normal to Pathological Conditions. Neuroendocrinology 2019; 108:244-255. [PMID: 30685760 DOI: 10.1159/000497214] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 01/24/2019] [Indexed: 11/19/2022]
Abstract
The exact physiological basis of acute growth hormone (GH) suppression by oral glucose is not fully understood. Glucose-mediated increase in hypothalamic somatostatin seems to be the most plausible explanation. Attempts to better understand its underlying mechanisms are compromised by species disparities in the response of GH to glucose load. While in humans, glucose inhibits GH release, the acute elevation of circulating glucose levels in rats has either no effect on GH secretion or may be stimulatory. Likewise, chronic hyperglycemia alters GH release in both humans and rats nonetheless in opposite directions. Several factors influence nadir GH concentrations including, age, gender, body mass index, pubertal age, and the type of assay used. Besides the classical suppressive effects of glucose on GH release, a paradoxical GH increase to oral glucose may be observed in around one third of patients with acromegaly as well as in various other disorders. Though its pathophysiology is poorly characterized, an altered interplay between somatostatin and GH-releasing hormone has been suggested and a link with pituitary ectopic expression of glucose-dependent insulinotropic polypeptide receptor has been recently demonstrated. A better understanding of the dynamics mediating GH response to glucose may allow a more optimal use of the OGTT as a diagnostic tool in various conditions, especially acromegaly.
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Affiliation(s)
- Mirella Hage
- Assistance Publique-Hôpitaux de Paris, Hôpital de Bicêtre, Service d'Endocrinologie et des Maladies de la Reproduction, Centre de Référence des Maladies Rares de l'Hypophyse, Institut National de la Santé et de la Recherche Médicale (Inserm) U1185, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Peter Kamenický
- Assistance Publique-Hôpitaux de Paris, Hôpital de Bicêtre, Service d'Endocrinologie et des Maladies de la Reproduction, Centre de Référence des Maladies Rares de l'Hypophyse, Institut National de la Santé et de la Recherche Médicale (Inserm) U1185, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Philippe Chanson
- Assistance Publique-Hôpitaux de Paris, Hôpital de Bicêtre, Service d'Endocrinologie et des Maladies de la Reproduction, Centre de Référence des Maladies Rares de l'Hypophyse, Institut National de la Santé et de la Recherche Médicale (Inserm) U1185, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France,
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Nishioka H, Fukuhara N, Yamaguchi-Okada M, Takeshita A, Takeuchi Y, Yamada S. Pitfalls in early biochemical evaluation after transsphenoidal surgery in patients with acromegaly. Endocr J 2017; 64:1073-1078. [PMID: 28835593 DOI: 10.1507/endocrj.ej17-0261] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Although the current remission criteria for acromegaly are clear and concise, some pitfalls have been reported in early endocrinological evaluation after surgery. To evaluate the long-term (>4 year) outcome and to detect the pitfalls in early evaluation, we retrospectively reviewed 128 patients with acromegaly who underwent primary transsphenoidal surgery during 2011 and 2012. These included 66 men and 62 women, aged from 7 to 76 (mean 46) years old. 49 patients (38.3%) were preoperatively treated with somatostatin analog (SSA). Follow-up period ranged from 52 to 75 (63) months. Long-term remission using the current consensus criteria was achieved in 107 patients (83.6%), 105 of which patient had achieved remission in early evaluation. In 5 patients with preoperative SSA treatment, IGF-1 levels re-elevated more than one year after surgery. Five female patients without pretreatment with SSA showed delayed normalization of IGF-1 between 13 to 27 months postoperatively, two of which patients satisfied the remission criteria. In conclusion, the long-term results can be reliably predicted by the remission criteria early after surgery in most patients with acromegaly. For the accurate evaluation within a year after surgery, however, influence of preoperative treatment with SSA, delayed normalization of IGF-1, and poor GH suppression due to low insulin resistance must be considered, particularly in women.
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Affiliation(s)
- Hiroshi Nishioka
- Department of Hypothalamic and Pituitary Surgery, Toranomon Hospital, Tokyo, Japan
- Okinaka Memorial Institute for Medical Research, Tokyo, Japan
| | - Noriaki Fukuhara
- Department of Hypothalamic and Pituitary Surgery, Toranomon Hospital, Tokyo, Japan
| | | | - Akira Takeshita
- Department of Endocrinology, Toranomon Hospital, Tokyo, Japan
- Okinaka Memorial Institute for Medical Research, Tokyo, Japan
| | - Yasuhiro Takeuchi
- Department of Endocrinology, Toranomon Hospital, Tokyo, Japan
- Okinaka Memorial Institute for Medical Research, Tokyo, Japan
| | - Shozo Yamada
- Department of Hypothalamic and Pituitary Surgery, Toranomon Hospital, Tokyo, Japan
- Okinaka Memorial Institute for Medical Research, Tokyo, Japan
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Kousoula K, Farmaki K, Skoglund T, Olsson DS, Johannsson G, Trimpou P, Ragnarsson O. The impact of adjustments to the diagnostic criteria for biochemical remission in surgically treated patients with acromegaly. Growth Horm IGF Res 2017; 36:16-21. [PMID: 28846862 DOI: 10.1016/j.ghir.2017.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 08/23/2017] [Accepted: 08/23/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND The suggested criteria for biochemical remission in patients treated for acromegaly were recently modified. The aim of this project was to study to what extent this modification influences remission rates. DESIGN, PATIENTS AND METHODS This was a retrospective study of 55 consecutive patients [29 men; median age 47years (interquartile range 38-68)] diagnosed with acromegaly between 2003 and 2014. After treatment serum IGF-I and/or GH was measured according to a standardized protocol. The biochemical remission status was defined according to the clinical guidelines from 2010 and2014. RESULTS Out of 55 patients, 44 patients were primarily operated. Of these, 33 (75%) were evaluated 3-12months postoperatively by measuring serum IGF-I and GH during an oral glucose tolerance test. According to the 2010 guidelines, 11 patients (33%) were in biochemical remission, 15 patients (46%) were not and 7 patients (21%) had discordant results (normal IGF-I and high GH or vice versa). Applying the 2014 guidelines in the same group, 16 patients (49%) were in biochemical remission, 7 patients (21%) were not and 10 patients (30%) had discordant results. Thus, by using the most recent criteria for biochemical control, more patients were considered to be in remission, or with discordant results, and fewer patients not in remission (P<0.05). CONCLUSION An apparently minor adjustment of the criteria for biochemical control has a significant impact on remission status in patients treated for acromegaly, eventually affecting follow-up and treatment strategies.
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Affiliation(s)
- Konstantina Kousoula
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Department of Endocrinology, Sahlgrenska University Hospital, Gröna Stråket 8, SE-413 45 Gothenburg, Sweden
| | - Katerina Farmaki
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Department of Endocrinology, Sahlgrenska University Hospital, Gröna Stråket 8, SE-413 45 Gothenburg, Sweden
| | - Thomas Skoglund
- Department of Neurosurgery, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Daniel S Olsson
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Department of Endocrinology, Sahlgrenska University Hospital, Gröna Stråket 8, SE-413 45 Gothenburg, Sweden
| | - Gudmundur Johannsson
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Department of Endocrinology, Sahlgrenska University Hospital, Gröna Stråket 8, SE-413 45 Gothenburg, Sweden
| | - Penelope Trimpou
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Department of Endocrinology, Sahlgrenska University Hospital, Gröna Stråket 8, SE-413 45 Gothenburg, Sweden
| | - Oskar Ragnarsson
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Department of Endocrinology, Sahlgrenska University Hospital, Gröna Stråket 8, SE-413 45 Gothenburg, Sweden.
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Rosario PW, Calsolari MR. Long-term follow-up of patients with elevated IGF-1 and nadir GH > 0.4 µg/L but < 1 µg/L. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2017; 61:426-431. [PMID: 28977166 PMCID: PMC10522245 DOI: 10.1590/2359-3997000000295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 06/11/2017] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To report the results of initial investigation and after 5 years of patients with a suspicious clinical scenario for acromegaly, elevated IGF-1, and nadir GH during an oral glucose tolerance test (OGTT) > 0.4 µg/L but < 1 µg/L. SUBJECTS AND METHODS Seventeen patients who had elevated IGF-1 (outside puberty and pregnancy) in two measurements and GH between 0.4 and 1 µg/L during OGTT were selected. RESULTS During initial assessment, only one patient had microadenoma on magnetic resonance imaging (MRI) of the pituitary. In this patient, IGF-1 returned to normal spontaneously after 5 years. In the remaining 16 patients, spontaneous normalization of IGF-1 was observed in four and IGF-1 continued to be elevated in 12 after 5 years. None of the latter patients developed a phenotype of acromegaly, changes in physiognomy or increase in IGF-1 and no tumor was detected by imaging methods. Two patients had nadir GH < 0.4 µg/L, while the nadir GH remained between 0.4 and 1 µg/L in 10 patients. CONCLUSION In patients (notably young adult or adult women) without a typical phenotype in whom IGF-1 is measured due to a suspicious clinical scenario and is found to be slightly elevated, even if confirmed and in the absence of other causes, a nadir GH cut-off value of 0.4 µg/L instead of 1 µg/L in the OGTT might be inadequate for the diagnosis.
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Affiliation(s)
- Pedro Weslley Rosario
- Santa Casa de Belo HorizonteMGBrasilServiço de Endocrinologia, Santa Casa de Belo Horizonte, MG, Brasil
| | - Maria Regina Calsolari
- Santa Casa de Belo HorizonteMGBrasilServiço de Endocrinologia, Santa Casa de Belo Horizonte, MG, Brasil
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Abstract
Measurements of human growth hormone (GH) and insulin-like growth-factor I (IGF-I) are cornerstones in the diagnosis of acromegaly. Both hormones are also used as biochemical markers in the evaluation of disease activity during treatment. Management of acromegaly is particularly challenging in cases where discordant information is obtained from measurement of GH concentrations following oral glucose load and from measurement of IGF-I. While in some patients biological factors can explain the discrepancy, in many cases issues with the analytical methods seem to be responsible. Assays used by endocrine laboratories to determine concentrations of GH and IGF-I underwent significant changes during the last decades. While generally leading to more sensitive and reproducible methods, these changes also had considerable impact on absolute concentrations measured. This must be reflected by updated decision limits, cut-offs and reference intervals. Since different commercially available assays do not agree very well, method specific interpretation of GH and IGF-I concentrations is required. This complexity in the interpretation of hormone concentrations is not always appropriately reflected in laboratory reports, but also not in clinical guidelines reporting decision limits not related to a specific analytical method. The present review provides an overview about methodological and biological variables affecting the biochemical assessment of acromegaly in diagnosis and follow up.
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Affiliation(s)
- Katharina Schilbach
- Clinical Endocrinology and Endocrine Laboratory, Medizinische Klinik und Poliklinik IV, Klinikum der Ludwig-Maximilians-Universität (LMU), Ziemssenstr. 1, 80336, Munich, Germany
| | - Christian J Strasburger
- Department of Endocrinology and Metabolic Diseases, Campus Charité Mitte, Charité Universitätsmedizin, Charitéplatz 1, 10117, Berlin, Germany
| | - Martin Bidlingmaier
- Endocrine Laboratory, Endocrine Research Unit, Medizinische Klinik und Poliklinik IV, Klinikum der Ludwig-Maximilians-Universität (LMU), Ziemssenstr. 1, 80336, Munich, Germany.
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Zeinalizadeh M, Habibi Z, Fernandez-Miranda JC, Gardner PA, Hodak SP, Challinor SM. Discordance between growth hormone and insulin-like growth factor-1 after pituitary surgery for acromegaly: a stepwise approach and management. Pituitary 2015; 18:48-59. [PMID: 24496953 DOI: 10.1007/s11102-014-0556-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
INTRODUCTION Follow-up management of patients with acromegaly after pituitary surgery is performed by conducting biochemical assays of growth hormone (GH) and insulin-like growth factor-1 (IGF1). Despite concordant results of these two tests in the majority of cases, there is increasing recognition of patients who show persistent or intermittent discordance between GH and IGF1 (normal GH and elevated IGF1 or vice versa). METHOD In this narrative review, the last three decades materials on the issue of discrepancy between GH and IGF1 were thoroughly assessed. RESULTS Various studies have obtained different discordance rates, ranging from 5.4 to 39.5%. At present, despite the use of current sensitive assays and more stringent criteria to define remission, the rate of discordance still remains high. A number of mechanisms have been proposed to explain the postoperative discordance of GH and IGF1 including; altered dynamics of the GH secretion after surgery, early postoperative hormone assay, inaccurate or less sensitive tests and laboratory errors, too high cut-off point for GH suppression in the GH assays, GH nadir values not adjusted to age, sex, and body mass index, the influence of concomitant medication, co-existing physiologic and pathologic conditions, and many other proposed reasons. Nevertheless, the underlying mechanisms are still far from clear, and the solution continues to evade complete elucidation. Similarly, the impacts of such a discrepancy over mortality and morbidity and the risk of biochemical and/or clinical recurrence are unclear. CONCLUSION As a challenging clinical problem, a stepwise evaluation and management of these patients appears to be more rational.
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Affiliation(s)
- Mehdi Zeinalizadeh
- Department of Neurological Surgery, Imam Khomeini Hospital, Tehran University of Medical Sciences, 1419733141, Tehran, Iran,
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Sze L, Neidert MC, Bernays RL, Zwimpfer C, Wiesli P, Haile SR, Brändle M, Schmid C. Gender dependence of serum soluble Klotho in acromegaly. Clin Endocrinol (Oxf) 2014; 80:869-73. [PMID: 24330426 DOI: 10.1111/cen.12385] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 09/12/2013] [Accepted: 12/08/2013] [Indexed: 01/01/2023]
Abstract
OBJECTIVES In acromegaly, disease activity is biochemically assessed by growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels. However, they are often discrepant, as several factors including gender influence their relationship. We recently found excessively high serum levels of soluble Klotho (sKl) in acromegalic patients, which depended on GH to a comparable extent as IGF-1. To further elucidate the relationship between GH and sKl, we examined the effect of gender on sKl in patients with untreated acromegaly. PATIENTS AND DESIGN We determined GH, IGF-1 and sKl in sera of 62 consecutive patients with newly diagnosed acromegaly (31 females/31 males, aged 20-85 years). RESULTS For their given GH excess at presentation with acromegaly, females had lower IGF-1 (490 ± 33 vs 604 ± 33 ng/ml, P = 0·02), but higher sKl [5171 ± 590 vs 3439 ± 431 pg/ml (mean ± SE), P = 0·02] levels than males. In multiple regression analysis, IGF-1 was closely associated with logGH (estimate 139, SE 47, P = 0·005) and BMI (estimate 14·2, SE 4·8, P = 0·005). sKl was closely associated with logGH (estimate 3088, SE 652, P = 0·0001) and gender (estimate 2034, SE 612, P = 0·002), and to a lesser extent with BMI (estimate 174, SE 66, P = 0·01). CONCLUSIONS For a given GH status, sKl concentrations are higher and IGF-1 concentrations are lower in women than in men. GH is the strongest predictor for both sKl and IGF-1, but gender needs to be considered when using these parameters for monitoring acromegalic patients.
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Affiliation(s)
- Lisa Sze
- Division of Endocrinology and Diabetes, University Hospital, Zurich, Switzerland; Division of Endocrinology and Diabetes, Kantonsspital St. Gallen, St. Gallen, Switzerland
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Abstract
Acromegaly is predominantly caused by a pituitary adenoma, which secretes an excess of GH resulting in increased IGF1 levels. Most of the GH assays used currently measure only the levels of the 22 kDa form of GH. In theory, the diagnostic sensitivity may be lower compared with the previous assays, which have used polyclonal antibodies. Many GH-secreting adenomas are plurihormonal and may co-secrete prolactin, TSH and α-subunit. Hyperprolactinaemia is found in 30-40% of patients with acromegaly, and hyperprolactinaemia may occasionally be diagnosed before acromegaly is apparent. Although trans-sphenoidal surgery of a GH-secreting adenoma remains the first treatment at most centres, the role of somatostatin analogues, octreotide long-acting repeatable and lanreotide Autogel as primary therapy is still the subject of some debate. Although the normalisation of GH and IGF1 levels is the main objective in all patients with acromegaly, GH and IGF1 levels may be discordant, especially during somatostatin analogue therapy. This discordance usually takes the form of high GH levels and an IGF1 level towards the upper limit of the normal range. Pasireotide, a new somatostatin analogue, may be more efficacious in some patients, but the drug has not yet been registered for acromegaly. Papers published on pasireotide have reported an increased risk of diabetes mellitus due to a reduction in insulin levels. Pegvisomant, the GH receptor antagonist, is indicated - alone or in combination with a somatostatin analogue - in most patients who fail to enter remission on a somatostatin analogue. Dopamine-D2-agonists may be effective as monotherapy in a few patients, but it may prove necessary to apply combination therapy involving a somatostatin analogue and/or pegvisomant.
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Affiliation(s)
- Marianne Andersen
- Department of Endocrinology, Odense University Hospital, Sønder Boulevard 29, 5000 Odense C, Denmark and Institute of Clinical Research, University of Southern Denmark, Odense C, Denmark
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Markkanen HM, Pekkarinen T, Välimäki MJ, Alfthan H, Hämäläinen E, Stenman UH. Comparison of two growth hormone stimulation tests and their cut-off limits in healthy adults at an outpatient clinic. Growth Horm IGF Res 2013; 23:165-169. [PMID: 23835226 DOI: 10.1016/j.ghir.2013.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 05/20/2013] [Accepted: 06/11/2013] [Indexed: 11/19/2022]
Abstract
OBJECTIVE A peak GH less than 3 μg/L to insulin tolerance test (ITT) is commonly used as a threshold indicating severe adult GH deficiency (GHD). This cut-off is based on results obtained by polyclonal radioimmunoassays preferably under standard conditions at hospital. Our aim was to evaluate the validity of this cut-off limit using two currently used immunometric GH assays and to compare GH responses in the ITT and the GH releasing hormone + arginine (GHRH + ARG) test in healthy adults at our outpatient endocrine unit. DESIGN ITT was performed on 73 subjects and the GHRH + ARG test on those 28 who showed insufficient response to the ITT. METHODS GH was measured by an immunofluorometric and immunochemiluminometric assay. RESULTS GH peak above 3 μg/L was observed in 56% of the healthy volunteers with adequate hypoglycemia in the ITT. Among the 28 subjects with a peak GH below 3 μg/L, only two overweight men had a GH peak response below the commonly used cut-off limit of 9.1 μg/L in the GHRH + ARG test. CONCLUSIONS Lean healthy adults could erroneously be classified as GH deficient by the ITT while their results in the GHRH + ARG test were normal. The GH results are highly dependent on the immunoassay used, but false positive results in the ITT are often obtained even if lower cutoff limits determined on the basis on the calibration of the GH assay are used. Confounding factors seemed to blunt the GH response to the ITT more than to the GHRH + ARG test at our outpatient clinic.
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Affiliation(s)
- Helene M Markkanen
- Department of Clinical Chemistry, Helsinki University Central Hospital, FI-00029 HUS, Finland
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13
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Boulo S, Hanisch K, Bidlingmaier M, Arsene CG, Panteghini M, Auclair G, Sturgeon C, Schimmel H, Zegers I. Gaps in the Traceability Chain of Human Growth Hormone Measurements. Clin Chem 2013; 59:1074-82. [DOI: 10.1373/clinchem.2012.199489] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND
Human growth hormone (hGH) is measured for the diagnosis of secretion disorders. These measurements fall under the EU Directive 98/79/EC on in vitro diagnostic medical devices requiring traceability of commercial calibrator values to higher-order reference materials or procedures (Off J Eur Communities 1998 Dec 7;L 331:1–37). External quality assessment schemes show large discrepancies between results from different methods, even though most methods provide results traceable to the recommended International Standard (IS 98/574). The aim of this study was to investigate possible causes for these discrepancies.
METHODS
We investigated the commutability and recovery of hGH in reconstituted IS 98/574. We tested different reconstitution protocols and used 4 different serum matrices for spiking. These IS preparations were measured together with serum samples. We quantified hGH by 5 different methods in 4 different laboratories.
RESULTS
Results from the different methods correlated well for the serum samples. Mean discrepancies between results from different methods were ≤20%. None of the IS preparations was commutable for all the method comparisons. The recovery of hGH in preparations of IS 98/574 depended on the reconstitution protocol (>10-fold differences) and BACKGROUND matrix (relative differences ≤17% for different serum matrices).
CONCLUSIONS
The use of different protocols for reconstitution and spiking of hGH reference preparations affects quantification by immunoassays, potentially leading to a bias between commercial methods, despite the use of calibrators with values claimed to be traceable to the same higher-order reference material.
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Affiliation(s)
- Sébastien Boulo
- Institute for Reference Materials and Measurements (IRMM), Joint Research Centre, European Commission, Geel, Belgium
| | - Katja Hanisch
- Institute for Reference Materials and Measurements (IRMM), Joint Research Centre, European Commission, Geel, Belgium
| | - Martin Bidlingmaier
- Endocrine Laboratory, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany
| | | | - Mauro Panteghini
- Centre for Metrological Traceability in Laboratory Medicine, University of Milan, Milan, Italy
| | - Guy Auclair
- Institute for Reference Materials and Measurements (IRMM), Joint Research Centre, European Commission, Geel, Belgium
| | - Catharine Sturgeon
- UK National External Quality Assessment Service (NEQAS) Edinburgh, Department of Laboratory Medicine, Royal Infirmary, Edinburgh, UK
| | - Heinz Schimmel
- Institute for Reference Materials and Measurements (IRMM), Joint Research Centre, European Commission, Geel, Belgium
| | - Ingrid Zegers
- Institute for Reference Materials and Measurements (IRMM), Joint Research Centre, European Commission, Geel, Belgium
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Arsene CG, Schulze D, Kratzsch J, Henrion A. High sensitivity mass spectrometric quantification of serum growth hormone by amphiphilic peptide conjugation. JOURNAL OF MASS SPECTROMETRY : JMS 2012; 47:1554-1560. [PMID: 23280743 DOI: 10.1002/jms.3094] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Revised: 08/15/2012] [Accepted: 08/16/2012] [Indexed: 06/01/2023]
Abstract
Amphiphilic peptide conjugation affords a significant increase in sensitivity with protein quantification by electrospray-ionization mass spectrometry. This has been demonstrated for human growth hormone (GH) in serum using N-(3-iodopropyl)-N,N,N-dimethyloctylammonium iodide as derivatizing reagent. The signal enhancement achieved is up to a factor of 5-6 and enables extension of the applicable concentration range down to the very low concentrations (≤ 1.0 µg/L) as encountered with clinical glucose suppression tests for patients with acromegaly. The method has been validated using a set of serum samples spiked with known amounts of recombinant 22 kDa GH in the range of 0.48 to 7.65 µg/L. The coefficient of variation (CV) calculated based on the deviation of results from the expected concentrations was 3.5%. The limit of detection (LoD) was determined as 0.1 µg/L and the limit of quantification (LoQ) as 0.4 µg/L. The potential of the method as a tool in clinical practice has been demonstrated with patient samples of about 1 µg/L.
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Affiliation(s)
- Cristian G Arsene
- Physikalisch-Technische Bundesanstalt, D-38116, Braunschweig, Germany.
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15
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Manolopoulou J, Alami Y, Petersenn S, Schopohl J, Wu Z, Strasburger CJ, Bidlingmaier M. Automated 22-kD growth hormone-specific assay without interference from Pegvisomant. Clin Chem 2012; 58:1446-56. [PMID: 22908135 DOI: 10.1373/clinchem.2012.188128] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Large variability exists among different growth hormone (GH) assays owing to differences in calibration, antibody specificity, isoform recognition, and interference from GH binding protein (GHBP). The GH receptor antagonist Pegvisomant presents a new challenge because Pegvisomant interferes with many GH assays. A recent consensus conference established criteria for standardization and evaluation of GH assays. Following consensus recommendations, we developed a new GH assay on an automated analyzer (IDS-iSYS, Immunodiagnostic Systems). METHODS A monoclonal antibody not cross-reacting with Pegvisomant was combined with a monoclonal antibody specific for 22-kD GH. Isoform specificity and interference from GHBP was tested and compared to that seen in 2 existing automated GH assays (Siemens Immulite, Diasorin Liaison). We also compared GH concentrations measured by the 3 assays for healthy volunteers and patients with acromegaly receiving different treatments. Using the iSYS assay, we also established nadir GH values during oral glucose load and analyzed changes in endogenous GH during Pegvisomant treatment. RESULTS Analytical and functional sensitivities were 0.01 μg/L and 0.04 μg/L, with a dynamic range from 0.04 to 100 μg/L. Intraassay CVs were 2%-4%, whereas interassay CVs were 5%-7% at GH concentrations between 1.7 and 27.5 μg/L. The assay was specific for 22-kD GH and not affected by GHBP. The presence of Pegvisomant, which leads to a negative bias on the Immulite and dramatic overestimation of GH on the Liaison, had no impact on the iSYS GH assay. CONCLUSIONS The new assay fulfils recent consensus recommendations and presents a useful new tool for reliable measurement of GH.
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Affiliation(s)
- Jenny Manolopoulou
- Endocrine Research Laboratories, Medizinische Klinik und Poliklinik IV, Ludwig Maximilians University, Munich, Germany
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Katznelson L, Atkinson JLD, Cook DM, Ezzat SZ, Hamrahian AH, Miller KK. American Association of Clinical Endocrinologists medical guidelines for clinical practice for the diagnosis and treatment of acromegaly--2011 update. Endocr Pract 2011; 17 Suppl 4:1-44. [PMID: 21846616 DOI: 10.4158/ep.17.s4.1] [Citation(s) in RCA: 156] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Laurence Katznelson
- Departments of Medicine and Neurosurgery, Stanford University, Stanford, California, USA
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18
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Quantification of growth hormone in serum by isotope dilution mass spectrometry. Anal Biochem 2010; 401:228-35. [DOI: 10.1016/j.ab.2010.03.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 02/08/2010] [Accepted: 03/05/2010] [Indexed: 11/21/2022]
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Lima GAB, Wu Z, Silva CMS, Barbosa FRP, Dias JS, Schrank Y, Strasburger CJ, Gadelha MR. Growth hormone isoforms in acromegalic patients before and after treatment with octreotide LAR. Growth Horm IGF Res 2010; 20:87-92. [PMID: 19884028 DOI: 10.1016/j.ghir.2009.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 10/02/2009] [Accepted: 10/05/2009] [Indexed: 11/30/2022]
Abstract
BACKGROUND Human growth hormone (hGH) circulates as a mixture of different isoforms. It has been previously reported that the ratio of 20kDa to 20kDa plus 22kDa (%20kDa-hGH) is increased in patients with active acromegaly. OBJECTIVES To evaluate the GH isoforms (20kDa- and 22kDa-hGH) in acromegalic patients before and after six months of treatment with octreotide LAR, and to compare the results with those in healthy controls. In addition, the relationships between the %20kDa-hGH, tumor size and biochemical measurements were also investigated. DESIGN Random serum samples from 23 acromegalic patients evaluated before and after six months of treatment with octreotide LAR and from 23 matched healthy controls were studied. Growth hormone, IGF-I and prolactin (PRL) were measured by chemiluminescence immunometric assay and the 20kDa- and 22kDa-hGH isoforms were measured by specific time-resolved fluorescence immunoassays. RESULTS In acromegalic patients before treatment, there was a significantly higher median %20Da-hGH in comparison to healthy controls (14.31% vs. 9.59%, p<0.001). After six months of treatment, the median %20kDa-hGH was similar to the baseline values. Patients with GH<2.5ng/mL after six months of treatment had already lower GH and %20kDa-hGH at baseline (p<0.01). The IGF-I (SD-scores) was positively correlated to total GH levels in acromegalic patients after treatment. There was no correlation between the %20kDa-hGH and PRL levels or tumor size. CONCLUSIONS Our study confirmed that acromegalic patients have an increased proportion of circulating 20kDa-hGH isoform. Consequently, the use of a 22kDa-hGH specific assay may underestimate the tumor production of total GH. Although octreotide LAR promoted a significant decrease in the GH and IGF-I levels, it did not normalize the GH isoforms composition and suggests that the secretion of GH isoforms is equally inhibited by somatostatin analogues and that it is the disease control that normalizes the GH isoforms composition in acromegaly.
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Affiliation(s)
- Giovanna A B Lima
- Division of Endocrinology, Department of Internal Medicine, Hospital Universitário Clementino Fraga Filho/Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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Bidlingmaier M, Freda PU. Measurement of human growth hormone by immunoassays: current status, unsolved problems and clinical consequences. Growth Horm IGF Res 2010; 20:19-25. [PMID: 19818659 PMCID: PMC7748084 DOI: 10.1016/j.ghir.2009.09.005] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Accepted: 09/17/2009] [Indexed: 01/28/2023]
Abstract
Measuring the concentration of growth hormone (GH) in blood samples taken during dynamic tests represents the basis for diagnosis of growth hormone related disorders, namely growth hormone deficiency and growth hormone excess. Today, a wide spectrum of immunoassays are in use, enabling rapid and sensitive determination of growth hormone concentrations in routine diagnostics. From a clinical point of view several difficulties exist with the use and interpretation of GH assay results in the assessment of GH related disorders: Many physiological factors such as fat mass, age and gender influence the outcome of dynamic tests, overall leading to significant inter-individual differences in GH responses. However, in addition to the physiological variability, considerable variability exists in GH assay results obtained by different immunoassays. Unfortunately, all the new technical advances in the field of GH measurement techniques have not reduced this methodological variability. To a large extent, the actual values reported for the GH concentration in a sample depend on the method used by the respective laboratory. Obviously, such discrepancies limit the applicability of consensus guidelines on diagnosis and treatment in clinical practice. This review summarizes current practices for GH measurement with respect to the methods used, their limitations and the clinical consequences of the existing heterogeneity in GH immunoassay results.
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Affiliation(s)
- Martin Bidlingmaier
- Endocrine Research Laboratories, Medizinische Klinik - Innenstadt, Ludwig-Maximilians University, Munich, Germany.
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21
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Tanaka S, Fukuda I, Hizuka N, Takano K. Gender differences in serum GH and IGF-I levels and the GH response to dynamic tests in patients with acromegaly. Endocr J 2010; 57:477-83. [PMID: 20203424 DOI: 10.1507/endocrj.k09e-342] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Gender affects the GH secretory pattern both in normal subjects and in patients with acromegaly by an uncertain mechanism. Here, we report the influence of gender on the relationship between serum GH and IGF-I levels and the GH response to dynamic tests in patients with acromegaly. Seventy-four patients with untreated acromegaly (M/F 27/47, age range 22-86 yr.) were studied. The serum GH levels did not differ between male and female (6.1 vs. 8.7 ng/ml; p=0.26), while serum IGF-I levels, IGF-I SDS and the IGF-I/GH ratio were lower in female than those in male (679 vs. 769 ng/ml; p<0.02, 7.3 vs. 9.2 SDS; p<0.02 and 79.6 vs. 141.5; p<0.05). When the subjects were divided into two groups: age <or=50 yr, and age >50 yr, serum IGF-I levels and IGF-I/GH ratios were lower in female than those in male in patients <or=50 yrs (650 vs. 1002 ng/ml; p<0.05 and 59.8 vs. 142.9; p<0.05), but not in patients >50 yrs (684 vs. 680 ng/ml; p=0.39 and 98.7 vs. 118.4; p=0.40). The GH responses to OGTT, TRH, octreotide, and bromocriptine tests were similar in male and female. In conclusion, IGF-I/GH ratio was significantly lower in female than that in male particularly in younger patients with acromegaly. These data suggest that gender, presumably sex steroids in female, may partially modulate the relationship between circulating IGF-I and GH levels in patients with acromegaly.
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Affiliation(s)
- Satoshi Tanaka
- Department of Medicine, Institute of Clinical Endocrinology Tokyo Women's Medical University, Tokyo, Japan
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Rosario PW, Salles DS, Bessa B, Furtado MS. Nadir growth hormone after oral glucose overload in obese subjects. ARQUIVOS BRASILEIROS DE ENDOCRINOLOGIA E METABOLOGIA 2010; 54:507-509. [PMID: 20694414 DOI: 10.1590/s0004-27302010000500013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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Rosário PWS, Furtado MS. Growth hormone after oral glucose overload: revision of reference values in normal subjects. ACTA ACUST UNITED AC 2009; 52:1139-44. [PMID: 19082302 DOI: 10.1590/s0004-27302008000700010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Accepted: 08/12/2008] [Indexed: 11/22/2022]
Abstract
The evaluation of growth hormone (GH) secretion continues to be important in acromegaly and the nadir GH (n-GH) level in the oral glucose tolerance test (OGTT) is the gold standard for the demonstration of secretory autonomy of this hormone. n-GH levels < 1 microg/L are defined as normal suppression but, using current assays, n-GH < 1 microg/L is detected in patients with untreated acromegaly and this value seems to be much lower in normal subjects. The objective of the present study was to evaluate n-GH levels in the OGTT in normal subjects using three different assays (GH ICMA Immulite; GH IRMA DSL and GH IFMA AutoDelfia). Two-hundred apparently healthy subjects (120 women) ranging in age from 18 to 70 years and with a BMI > 18.5 and < 27 kg/m(2), who used no medications and presented normal glycemia, blood count, albumin, creatinine, TSH, SGOT, SGPT and bilirubin were studied. Serum samples were obtained before and 30,60,90 and 120 min after oral administration of 75 g glucose. The test was repeated after 4 weeks in 157 participants, with the same protocol being used in 79 and 78 receiving an overload of 100 g glucose. n-GH cut-off values (97.5th percentile) were higher in women than in men (GH-IFMA: 0.30 versus 0.11 microg/L; GH-ICMA: 0.60 versus 0.25 microg/L; GH-IRMA: 0.20 versus 0.10 microg/L, respectively). No correlation was observed between n-GH and age or BMI. A difference was only observed when comparing women < 35 years (n = 40) versus > 35 years (n = 80), with higher values in the former (n-GH cut-off in this subgroup: GH-IFMA 0.40 versus 0.26 microg/L, GH-ICMA 0.74 versus 0.50 microg/L, GH-IRMA 0.25 versus 0.15 microg/L). A good correlation was observed between the assays (r = 0.9-0.96), however, the highest values were always obtained with the Immulite assay. Test repetition with 75 g oral glucose showed a variation in n-GH < 10.2% (GH-IFMA), < 13.4% (GH-ICMA) and < 11% (GH-IRMA) in 95% of the subjects. This variation was similar when the test was repeated with 100 g glucose. A good correlation was observed between n-GH in the first and second test (r = 0.83-0.92). We suggest the following n-GH reference values: for men, 0.14 microg/L for the GH IRMA DSL and GH IFMA AutoDelfia kits and 0.25 microg/L for the GH ICMA Immulite kit; for women, 0.25 microg/L, 0.40 microg/L and 0.70 microg/L, respectively.
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Abstract
Monitoring of a patient with acromegaly requires periodic evaluation of levels of GH and IGF-1, the biochemical markers of this disease. Although the results of these two tests are usually concordant, they can be discrepant and how to proceed when they are can be a challenging clinical problem. In some cases, IGF-1 levels are normal yet GH suppression after oral glucose is abnormal; this pattern may be due to persistent GH dysregulation despite remission. In other cases, IGF-1 levels are elevated yet GH suppression appears to be normal; this pattern may be observed if the cutoff for GH suppression is inappropriately high for the GH assay being used. Various conditions known to alter GH and IGF-1 including malnutrition, thyroid disease and oestrogen use as well as the potential for methodological or normative data issues with the GH and IGF-1 assays should be considered in the interpretation of discrepant results. When a known cause of the discrepancy other than acromegaly is not identified, a clinical decision about the patient's therapy needs to be made. We adjust treatment in most patients whose results are discrepant based on the IGF-1 level, continuing current treatment if it is persistently normal or modifying this if it is elevated. The clinical picture of the patient, however, also needs to be incorporated into this decision. All patients should have continued periodic surveillance of both GH and IGF-1 levels.
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Affiliation(s)
- Pamela U Freda
- College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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25
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Abstract
Disorders affecting GH secretion--either GH deficiency or GH excess (acromegaly)--are biochemically defined through peak or nadir concentrations of human GH in response to dynamic tests. Immunoassays employing polyclonal or monoclonal antibodies are routinely used for the analysis of GH concentrations, and many different assays are available on the market today. Unfortunately, the actual value reported for the GH concentration in a specific patient's sample to a large extent depends on the assay method used by the respective laboratory. Variability between assay results exceeds 200%, limiting the applicability of consensus guidelines in clinical practice. Reasons for the heterogeneity in GH assay results include the heterogeneity of the analyte itself, the availability of different preparations for calibration, and the interference from matrix components such as GH-binding protein. Furthermore, the reporting of results in mass units or international units together with the application of variable conversion factors led to confusion. International collaborations proposed measures to improve the comparability of assay results, recommending the use of a single, recombinant calibrator for all assays and reporting only in mass units as first steps. However, because of the differences in epitope specificity of antibodies used in different assays, method-specific cut-off levels for dynamic tests might remain necessary to correctly interpret and compare results from different laboratories.
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Affiliation(s)
- Martin Bidlingmaier
- Endocrine Research Laboratories, Medizinische Klinik, Innenstadt, Ludwig-Maximilians University, Ziemssenstreet 1, 80336 Munich, Germany.
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Pandey V, Perry JK, Mohankumar KM, Kong XJ, Liu SM, Wu ZS, Mitchell MD, Zhu T, Lobie PE. Autocrine human growth hormone stimulates oncogenicity of endometrial carcinoma cells. Endocrinology 2008; 149:3909-19. [PMID: 18450952 PMCID: PMC2488240 DOI: 10.1210/en.2008-0286] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recent published data have demonstrated elevated levels of human GH (hGH) in endometriosis and endometrial adenocarcinoma. Herein, we demonstrate that autocrine production of hGH can enhance the in vitro and in vivo oncogenic potential of endometrial carcinoma cells. Forced expression of hGH in endometrial carcinoma cell lines RL95-2 and AN3 resulted in an increased total cell number through enhanced cell cycle progression and decreased apoptotic cell death. In addition, autocrine hGH expression in endometrial carcinoma cells promoted anchorage-independent growth and increased cell migration/invasion in vitro. In a xenograft model of human endometrial carcinoma, autocrine hGH enhanced tumor size and progression. Changes in endometrial carcinoma cell gene expression stimulated by autocrine hGH was consistent with the altered in vitro and in vivo behavior. Functional antagonism of hGH in wild-type RL95-2 cells significantly reduced cell proliferation, cell survival, and anchorage-independent cell growth. These studies demonstrate a functional role for autocrine hGH in the development and progression of endometrial carcinoma and indicate potential therapeutic relevance of hGH antagonism in the treatment of endometrial carcinoma.
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Affiliation(s)
- Vijay Pandey
- Liggins Institute and National Research Centre for Growth and Development, University of Auckland, 2-6 Park Avenue, Private Bag 92019 Auckland, New Zealand
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Perry JK, Mohankumar KM, Emerald BS, Mertani HC, Lobie PE. The contribution of growth hormone to mammary neoplasia. J Mammary Gland Biol Neoplasia 2008; 13:131-45. [PMID: 18253708 PMCID: PMC2665193 DOI: 10.1007/s10911-008-9070-z] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Accepted: 01/02/2008] [Indexed: 12/13/2022] Open
Abstract
While the effects of growth hormone (GH) on longitudinal growth are well established, the observation that GH contributes to neoplastic progression is more recent. Accumulating literature implicates GH-mediated signal transduction in the development and progression of a wide range malignancies including breast cancer. Recently autocrine human GH been demonstrated to be an orthotopically expressed oncogene for the human mammary gland. This review will highlight recent evidence linking GH and mammary carcinoma and discuss GH-antagonism as a potential therapeutic approach for treatment of breast cancer.
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Affiliation(s)
- Jo K Perry
- The Liggins Institute and the National Research Centre for Growth and Development
University of Auckland2-6 Park Avenue, Grafton, Private Bag 92019, Auckland 1023,NZ
| | - Kumarasamypet M Mohankumar
- The Liggins Institute and the National Research Centre for Growth and Development
University of Auckland2-6 Park Avenue, Grafton, Private Bag 92019, Auckland 1023,NZ
| | - B Starling Emerald
- The Liggins Institute and the National Research Centre for Growth and Development
University of Auckland2-6 Park Avenue, Grafton, Private Bag 92019, Auckland 1023,NZ
| | - Hichem C Mertani
- PICM, Physiologie intégrative, cellulaire et moléculaire
CNRS : UMR5123Université Claude Bernard - Lyon IBât. R. Dubois
43, Bvd du 11 Novembre 1918
69622 VILLEURBANNE CEDEX,FR
| | - Peter E Lobie
- The Liggins Institute and the National Research Centre for Growth and Development
University of Auckland2-6 Park Avenue, Grafton, Private Bag 92019, Auckland 1023,NZ
- Department of Molecular Medicine and Pathology
University of AucklandFaculty of Medical and Health Sciences, Private Bag 92019, Auckland, New Zealand,NZ
- * Correspondence should be adressed to: Peter E Lobie
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Evaluation of two highly sensitive assays for serum IGF-1 and GH determination following oral glucose tolerance test in healthy controls. ACTA ACUST UNITED AC 2008; 55:111-6. [PMID: 22967876 DOI: 10.1016/s1575-0922(08)70646-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Accepted: 10/15/2007] [Indexed: 11/21/2022]
Abstract
OBJECTIVE To evaluate 2 highly sensitive assays for serum insulin-like growth factor-1 (IGF-1) and growth hormone (GH) determination following an oral glucose tolerance test (OGTT) in healthy controls. METHODS Nineteen healthy adults underwent a standard 75g OGTT and GH and IGF-1 were measured. Serum GH and IGF-1 levels were assayed by a sensitive immunoradiometric assay (IRMA) and a highly sensitive chemiluminescent immunometric assay (CLIA). RESULTS The mean IGF-1 concentration was 153±65ng/ml measured by IRMA and 144±56ng/ml measured by CLIA. The median (interquartile range) basal GH concentrations by IRMAvs CLIA were 0.8 (0.5-3) μg/l vs 0.5 (0.1-2.4) μg/l. The median nadir GH measured by IRMA in these subjects was 0.4 (0.3-0.5) μg/l, and the mean nadir GH by CLIA was 0.08 (0.01-0.22) μg/I. When a ratio of basal IRMA/CLIA GH was calculated in each subject, the median ratio of basal IRMA/CLIA GH concentrations in subjects overall was 1.68. Similarly, the median ratio of nadir IRMA/CLIA GH values was 4.44. One of the subjects did not achieve GH suppression into the established normal range, with a GH nadir of 1.2 μg/l by IRMA and 1 μg/l by CLIA, overlapping with the traditional cut-off defining acromegaly when GH suppression was measured by IRMA. CONCLUSIONS Highly sensitive chemiluminescent immunometric assays should be used to assess the GH/IGF-1 axis. In our opinion, there is no need for a lower GH suppression cut-off for diagnosing acromegaly. We found no significant gender-, BMI- or age-related differences in nadir GH levels and thus our results do not support different OGTT criteria for screening of acromegaly in men and women, or in younger and older subjects.
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Cazabat L, Souberbielle JC, Chanson P. Dynamic tests for the diagnosis and assessment of treatment efficacy in acromegaly. Pituitary 2008; 11:129-39. [PMID: 18418712 DOI: 10.1007/s11102-008-0113-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
In the vast majority of cases, basal serum GH and IGF-1 levels are markedly increased in patients with obvious clinical signs and symptoms of acromegaly. The oral glucose tolerance test (OGTT) is useful for diagnosis in the minority of patients who have weak GH hypersecretion. The cutoff for a "normal" GH nadir in the OGTT remains to be agreed. The type of GH assay, its sensitivity, the type of standard used by the manufacturer, the patient's age and especially gender, must all be taken into account. Recent studies using new highly sensitive assays suggest an upper normal GH nadir of 0.71 microg/l for female healthy patients, but no "universal" cut-off has yet been defined for healthy males (from 0.057 to 0.25 microg/l). The 1 microg/l cutoff proposed for the diagnosis of acromegaly in a 2000 consensus should be abandoned in favor of a 0.30 microg/l cutoff. Clinicians should know which assay is used, together with its sensitivity and the standard, before making therapeutic decisions. A more pragmatic view should probably be adopted when assessing the treatment response. Indeed, if "cure" is defined not with the <1 microg/l GH nadir but on the basis of healthy control values, many patients will not be considered controlled. However, the clinical relevance of such goal (e.g. achieving GH nadir <0.4 microg/l rather than <1 microg/l) in terms of prognosis and prediction of outcome on long term is not firmly established. Thus, from a pragmatic point of view, achieving a normal age-adjusted IGF-1 level and a GH nadir below 1 microg/l during OGTT will probably remain relevant for defining remission and good disease control in terms of morbidity and mortality in acromegaly.
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Affiliation(s)
- Laure Cazabat
- Service d'Endocrinologie et Maladies de la Reproduction, Hôpital de Bicêtre, Le-Kremlin-Bicetre, France
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Schmid C, Krayenbuehl PA, Bernays RL, Zwimpfer C, Maly FE, Wiesli P. Growth Hormone (GH) Receptor Isoform in Acromegaly: Lower Concentrations of GH but Not Insulin-Like Growth Factor-1 in Patients with a Genomic Deletion of Exon 3 in the GH Receptor Gene. Clin Chem 2007; 53:1484-8. [PMID: 17573420 DOI: 10.1373/clinchem.2007.085712] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Background: A genomic deletion of exon 3 (d3-GHR) of the growth hormone (GH) receptor (GHR) has been linked to the effectiveness of GH therapy in children with GH deficiency. Carriers of the d3-GHR genotype had higher GH-induced growth rates than children homozygous for the full-length (fl)-GHR. The aim of this study was to test whether the relationship between GH and insulin-like growth factor-1 (IGF-1) concentrations is influenced by the GHR genotype in patients with acromegaly.
Methods: Study participants were 44 adult patients with established diagnosis of acromegaly. The genotype of the GHR was determined in leukocyte DNA from peripheral blood. Clinical and biochemical findings at the time of diagnosis of acromegaly were obtained from the medical records of the patients.
Results: fl-GHR homozygosity was found in 22 (50%) of patients, and 22 (50%) of patients had at least 1 d3 allele (d3-GHR). Demographic and clinical characteristics (age, height, weight, estimated duration of disease, and mean tumor size) of the 2 groups were comparable. Median (range) serum IGF-1 concentrations at the time of diagnosis were 670 (447–1443) μg/L in the fl-GHR group and 840 (342–1494) μg/L in the d3-GHR group (P = not significant). Basal GH concentrations were higher in the fl-GHR group [29.7 (3.8–159) μg/L] than in the d3-GHR group [8.4 (2.6–74 μg/L), P = 0.002], and so were mean (30.4 vs 6.1 μg/L, P = 0.005) and nadir (20.5 vs 5.1 μg/L, P = 0.003) GH concentrations during an oral glucose tolerance test.
Conclusions: The GHR fl/d3 genotype modulates the relationship between GH and IGF-1 concentrations in patients presenting with acromegaly.
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Affiliation(s)
- Christoph Schmid
- University Hospital of Zurich, Department of Internal Medicine, Division of Endocrinology and Diabetes, Zurich, Switzerland
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Pokrajac A, Wark G, Ellis AR, Wear J, Wieringa GE, Trainer PJ. Variation in GH and IGF-I assays limits the applicability of international consensus criteria to local practice. Clin Endocrinol (Oxf) 2007; 67:65-70. [PMID: 17437512 DOI: 10.1111/j.1365-2265.2007.02836.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND There is increasing reliance on consensus criteria for decision making. Recent criteria state that acromegaly is excluded by a nadir GH during an oral glucose tolerance test (OGTT) of < 1 microg/l and a normal level of IGF-I. OBJECTIVE To study GH and IGF-I assay performance close to cut-off values for active acromegaly. DESIGN AND METHODS Two serum samples known to give borderline results were sent to all centres participating in the UK National External Quality Assessment Service (NEQAS). Sample A was assigned to be a nadir during an OGTT and sent for GH assessment to 104 centres. Sample B, with a clinical scenario, was sent to 23 centres that measure IGF-I, and these centres were asked to measure IGF-I, interpret the result and provide the source of their reference ranges (RRs). RESULTS For sample A, the median GH was 2.6 mU/l (range 1.04-3.5 mU/l). Applying a conversion factor (CF) of 2.0 (1 microg/l = 2 mU/l), the most negatively biased method classified 10% of the values consistent with acromegaly, while the most positively biased method classified all values as consistent with the diagnosis. Applying a CF of 3.0 (1 microg/l = 3 mU/l), only 11% of results were consistent with acromegaly. For sample B, the median IGF-I was 50.8 nmol/l (range 24.3-60.9 nmol/l). All centres used age-related RRs. There was a 50% variation in the upper limit of the RRs between centres. Overall, 30% of the IGF-I results were against the diagnosis. There was little agreement in the RRs quoted by centres using the same method. CONCLUSION Variability in assay performance, coupled with use of inappropriate CFs and RRs, undermines the applicability of international consensus criteria to local practice.
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Affiliation(s)
- A Pokrajac
- Christie Hospital NHS Trust, Department of Endocrinology, Manchester, UK
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Bidlingmaier M, Strasburger CJ. What endocrinologists should know about growth hormone measurements. Endocrinol Metab Clin North Am 2007; 36:101-8. [PMID: 17336737 DOI: 10.1016/j.ecl.2006.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Determination of human growth hormone (GH) concentration in serum plays a key role in the diagnosis of GH deficiency and GH excess (acromegaly). Methods of measuring GH still lack standardization and show considerable between-method variability. Therefore, correct interpretation of GH test results requires knowledge of measurement techniques and awareness of potential problems in applying recommendations for cut-off values given in the literature. This article focuses on the molecular, structural, and methodologic background of the heterogeneity of assay results and on possible next steps toward standardization.
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Affiliation(s)
- Martin Bidlingmaier
- Endocrine Research Laboratories, Medizinische Klinik-Innenstadt, Ludwig-Maximilians University, Ziemssenstrasse 1, Munich 80336, Germany.
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Abstract
Measurement of circulating growth hormone (GH) concentrations is essential in diagnosis of either GH deficiency or GH excess. The invention of immunoassays for the measurement of peptide hormones was a major breakthrough, enabling the routine analysis of GH concentrations in larger series of samples. Over the last few decades, measurement technology has evolved from less sensitive, mainly radioactive assays based on polyclonal antisera to the latest generations of highly sensitive chemiluminescence methods employing monoclonal antibodies. Unfortunately, the development of newer assays did not lead to better agreement among the results obtained by different assay methods. On the contrary, the differences tended to increase when monoclonal antibody based assays became more popular. The actual value reported for the GH concentration in a specific patient's sample still mainly depends on the method used by the respective laboratory, limiting the applicability of international consensus guidelines in clinical practice. The heterogeneity of the analyte itself, the availability of different reference preparations for calibration and the interference from matrix components such as GH binding protein are among the reasons why standardizing GH assays is difficult. An additional challenge arose from the availability of a GH receptor antagonist for the treatment of acromegaly, which is basically a mutated form of GH and therefore interferes in many GH assays. This review provides an overview on GH assays used in clinical practice, their limitations and the potential next steps towards standardization.
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Affiliation(s)
- Martin Bidlingmaier
- Endocrine Research Laboratories, Medizinische Klinik-Innenstadt, Ludwig-Maximilians University, Ziemssenstr. 1, 80336 Munich, Germany.
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