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Kawalec J, Horzelski W, Karbownik-Lewińska M, Lewiński A, Lewandowski KC. Determination of glucose cut-off points for optimal performance of glucagon stimulation test. Front Endocrinol (Lausanne) 2024; 15:1448467. [PMID: 39262672 PMCID: PMC11387979 DOI: 10.3389/fendo.2024.1448467] [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: 06/13/2024] [Accepted: 08/07/2024] [Indexed: 09/13/2024] Open
Abstract
Introduction The glucagon stimulation test (GST) is widely used to assess growth hormone (GH) and cortisol secretion, nevertheless the precise mechanisms underpinning these hormonal responses remain unclear. We have endeavoured to explore the relationship between glucose and insulin fluctuations during GST and their impact on GH and cortisol secretion. Subjects and methods We retrospectively studied 139 subjects (mean age 35.5 ± 15.1 years, BMI 26.6 ± 6.61 kg/m²), including 62 individuals with a history of pituitary disease (27 with an intact adrenal axis) and 77 healthy controls. Standard dose intramuscular GST was performed in all subjects. Results Once BMI and age were excluded from multivariate model, the nadir of glucose concentration during GST was the sole variable associated with maximal GH secretion (ΔGH, p<0.0003), while neither glucose/insulin peak, nor Δglucose/Δinsulin concentrations contributed to ΔGH. 100% pass rate for GH secretion above 3 ng/ml or 1.07 ng/ml cut-offs was observed for glucose concentrations at, or below 60 mg/dl (3.33 mmol/l) (for Controls), or 62 mg/dl (3.44 mmol/l) (for Controls and patients with an intact adrenocortical axis). Such low glucose concentrations were obtained, however, only in about 30% of studied individuals. Conversely, cortisol secretion did not correlate with glucose or insulin fluctuations, suggesting alternative regulatory mechanisms. Conclusions This study reveals that glucose nadir below 3.33 mmol/l is the only biochemical biovariable linked with optimal GH secretion during GST, whereas mechanisms responsible for cortisol secretion remain unclear. We emphasize the importance of glucose monitoring during GST to validate GH stimulation and support clinical decisions in GH deficiency management.
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Affiliation(s)
- Joanna Kawalec
- Department of Endocrinology & Metabolic Diseases, Polish Mother's Memorial Hospital Research Institute, Lodz, Poland
| | - Wojciech Horzelski
- Faculty of Mathematics and Computer Science, University of Lodz, Lodz, Poland
| | - Małgorzata Karbownik-Lewińska
- Department of Endocrinology & Metabolic Diseases, Polish Mother's Memorial Hospital Research Institute, Lodz, Poland
- Department of Endocrinology & Metabolic Diseases, The Medical University of Lodz, Lodz, Poland
| | - Andrzej Lewiński
- Department of Endocrinology & Metabolic Diseases, Polish Mother's Memorial Hospital Research Institute, Lodz, Poland
| | - Krzysztof C Lewandowski
- Department of Endocrinology & Metabolic Diseases, The Medical University of Lodz, Lodz, Poland
- Faculty of Medicine, Mazovian University in Plock, Plock, Poland
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Cuboni D, Caputo M, Ghigo E, Aimaretti G, Gasco V. Once upon a time: the glucagon stimulation test in diagnosing adult GH deficiency. J Endocrinol Invest 2024; 47:1621-1631. [PMID: 38461479 PMCID: PMC11196325 DOI: 10.1007/s40618-024-02322-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/26/2024] [Indexed: 03/12/2024]
Abstract
PURPOSE The clinical features of adult GH deficiency (GHD) are nonspecific, and its diagnosis is established through GH stimulation testing, which is often complex, expensive, time-consuming and may be associated with adverse side effects. Moreover, diagnosing adult GHD can be challenging due to the influence of age, gender, and body mass index on GH peak at each test. The insulin tolerance test (ITT), GHRH + arginine test, glucagon stimulation test (GST), and, more recently, testing with macimorelin are all recognized as useful in diagnosing adult GHD. To date GST is still little used, but due to the unavailability of the GHRH all over the world and the high cost of macimorelin, in the next future it will probably become the most widely used test when ITT is contraindicated. The aim of the present review is to describe the current knowledge on GST. METHODS Narrative review. RESULTS In the last years several studies have suggested some changes in the original GST protocol and have questioned its diagnostic accuracy when the classic GH cut-point of 3 μg/L is used, suggesting to use a lower GH cut-point to improve its sensitivity and specificity in overweight/obese patients and in those with lower pretest GHD probability. CONCLUSION This document provides an update on the utility of GST, summarizes how to perform the test, shows which cut-points should be used in interpreting the results, and discusses its drawbacks and caveats referring to the most recent studies.
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Affiliation(s)
- D Cuboni
- Division of Endocrinology, Diabetes and Metabolism, Department of Medical Science, ASOU "Città della Salute e Della Scienza" di Torino, University of Turin, C.So Dogliotti 14, 10126, Turin, Italy
| | - M Caputo
- Department of Health Sciences, Università del Piemonte Orientale, Novara, Italy
- Endocrinology, Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - E Ghigo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medical Science, ASOU "Città della Salute e Della Scienza" di Torino, University of Turin, C.So Dogliotti 14, 10126, Turin, Italy
| | - G Aimaretti
- Endocrinology, Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - V Gasco
- Division of Endocrinology, Diabetes and Metabolism, Department of Medical Science, ASOU "Città della Salute e Della Scienza" di Torino, University of Turin, C.So Dogliotti 14, 10126, Turin, Italy.
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Tausendfreund O, Bidlingmaier M, Martini S, Reif H, Rippl M, Schilbach K, Schmidmaier R, Drey M. The somatotroph pituitary gland function in high-aged multimorbid hospitalized patients with IGF-I deficiency. Pituitary 2024:10.1007/s11102-024-01406-y. [PMID: 38819617 DOI: 10.1007/s11102-024-01406-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/17/2024] [Indexed: 06/01/2024]
Abstract
PURPOSE It is unclear whether the age-related decline in the somatotropic axis stems from a reduced growth hormone (GH) production in the pituitary gland, or from a peripheral origin akin to an acquired GH resistance. With the help of a GHRH/arginine test, high-aged multimorbid hospitalized patients with IGF-I deficiency are to be tested to determine whether there is primarily a pituitary GH deficiency in the sense of a somatopause. METHODS Seventeen multimorbid patients (eleven men and six women) with a mean age of 82 years, with IGF-I concentrations below two standard deviations of 30-year-old men and women were identified. Patients suffered from a variety of common age-related stable diseases including coronary artery disease, chronic liver or kidney disease, chronic heart failure as well as acute conditions e.g., urosepsis or endocarditis. To assess the somatotropic axis they underwent a GHRH/arginine test. Results were evaluated using descriptive statistics. RESULTS In average, the peak concentration of GH after stimulation was 14.8 µg/L with a range from 2.76 to 47.4 µg/L. Taking into account both, gender and BMI (with a mean of 26.5 kg/m²) for each participant, the pituitary gland was adequately stimulated in 16 out of the 17 patients. No patient reported common side effects related to the GHRH/arginine test. CONCLUSION The somatotroph pituitary gland retains its secretory capacity in the advanced aged. Therefore, age does not seem to be the driving pacemaker for the functional decline of the somatotropic axis within the aged population.
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Affiliation(s)
| | - Martin Bidlingmaier
- Department of Medicine IV, University Hospital, LMU Munich, München, Germany
| | - Sebastian Martini
- Department of Medicine IV, University Hospital, LMU Munich, München, Germany
| | - Hannah Reif
- Department of Medicine IV, University Hospital, LMU Munich, München, Germany
| | - Michaela Rippl
- Department of Medicine IV, University Hospital, LMU Munich, München, Germany
| | - Katharina Schilbach
- Department of Medicine IV, University Hospital, LMU Munich, München, Germany
- Deggendorf Institute of Technology, Deggendorf, Germany
| | - Ralf Schmidmaier
- Department of Medicine IV, University Hospital, LMU Munich, München, Germany
| | - Michael Drey
- Department of Medicine IV, University Hospital, LMU Munich, München, Germany
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Watson MD, Cross BL, Grosicki GJ. Evidence for the Contribution of Gut Microbiota to Age-Related Anabolic Resistance. Nutrients 2021; 13:706. [PMID: 33672207 PMCID: PMC7926629 DOI: 10.3390/nu13020706] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/08/2021] [Accepted: 02/19/2021] [Indexed: 12/11/2022] Open
Abstract
Globally, people 65 years of age and older are the fastest growing segment of the population. Physiological manifestations of the aging process include undesirable changes in body composition, declines in cardiorespiratory fitness, and reductions in skeletal muscle size and function (i.e., sarcopenia) that are independently associated with mortality. Decrements in muscle protein synthetic responses to anabolic stimuli (i.e., anabolic resistance), such as protein feeding or physical activity, are highly characteristic of the aging skeletal muscle phenotype and play a fundamental role in the development of sarcopenia. A more definitive understanding of the mechanisms underlying this age-associated reduction in anabolic responsiveness will help to guide promyogenic and function promoting therapies. Recent studies have provided evidence in support of a bidirectional gut-muscle axis with implications for aging muscle health. This review will examine how age-related changes in gut microbiota composition may impact anabolic response to protein feeding through adverse changes in protein digestion and amino acid absorption, circulating amino acid availability, anabolic hormone production and responsiveness, and intramuscular anabolic signaling. We conclude by reviewing literature describing lifestyle habits suspected to contribute to age-related changes in the microbiome with the goal of identifying evidence-informed strategies to preserve microbial homeostasis, anabolic sensitivity, and skeletal muscle with advancing age.
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Affiliation(s)
| | | | - Gregory J. Grosicki
- Biodynamics and Human Performance Center, Georgia Southern University (Armstrong Campus), Savannah, GA 31419, USA; (M.D.W.); (B.L.C.)
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Tyrosine Hydroxylase Neurons Regulate Growth Hormone Secretion via Short-Loop Negative Feedback. J Neurosci 2020; 40:4309-4322. [PMID: 32317389 DOI: 10.1523/jneurosci.2531-19.2020] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 03/30/2020] [Accepted: 04/03/2020] [Indexed: 02/07/2023] Open
Abstract
Classical studies suggest that growth hormone (GH) secretion is controlled by negative-feedback loops mediated by GH-releasing hormone (GHRH)- or somatostatin-expressing neurons. Catecholamines are known to alter GH secretion and neurons expressing TH are located in several brain areas containing GH-responsive cells. However, whether TH-expressing neurons are required to regulate GH secretion via negative-feedback mechanisms is unknown. In the present study, we showed that between 50% and 90% of TH-expressing neurons in the periventricular, paraventricular, and arcuate hypothalamic nuclei and locus ceruleus of mice exhibited STAT5 phosphorylation (pSTAT5) after an acute GH injection. Ablation of GH receptor (GHR) from TH cells or in the entire brain markedly increased GH pulse secretion and body growth in both male and female mice. In contrast, GHR ablation in cells that express the dopamine transporter (DAT) or dopamine β-hydroxylase (DBH; marker of noradrenergic/adrenergic cells) did not affect body growth. Nevertheless, less than 50% of TH-expressing neurons in the hypothalamus were found to express DAT. Ablation of GHR in TH cells increased the hypothalamic expression of Ghrh mRNA, although very few GHRH neurons were found to coexpress TH- and GH-induced pSTAT5. In summary, TH neurons that do not express DAT or DBH are required for the autoregulation of GH secretion via a negative-feedback loop. Our findings revealed a critical and previously unidentified group of catecholaminergic interneurons that are apt to sense changes in GH levels and regulate the somatotropic axis in mice.SIGNIFICANCE STATEMENT Textbooks indicate until now that the pulsatile pattern of growth hormone (GH) secretion is primarily controlled by GH-releasing hormone and somatostatin neurons. The regulation of GH secretion relies on the ability of these cells to sense changes in circulating GH levels to adjust pituitary GH secretion within a narrow physiological range. However, our study identifies a specific population of tyrosine hydroxylase-expressing neurons that is critical to autoregulate GH secretion via a negative-feedback loop. The lack of this mechanism in transgenic mice results in aberrant GH secretion and body growth. Since GH plays a key role in cell proliferation, body growth, and metabolism, our findings provide a major advance to understand how the brain regulates the somatotropic axis.
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Bhandari SS, Narayan H, Jones DJ, Suzuki T, Struck J, Bergmann A, Squire IB, Ng LL. Plasma growth hormone is a strong predictor of risk at 1 year in acute heart failure. Eur J Heart Fail 2015; 18:281-9. [DOI: 10.1002/ejhf.459] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 10/08/2015] [Accepted: 10/22/2015] [Indexed: 11/08/2022] Open
Affiliation(s)
- Sanjay S. Bhandari
- Department of Cardiovascular Sciences; University of Leicester; Leicester UK
- NIHR Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital; University of Leicester; Leicester UK
| | - Hafid Narayan
- Department of Cardiovascular Sciences; University of Leicester; Leicester UK
- NIHR Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital; University of Leicester; Leicester UK
| | - Donald J.L. Jones
- Department of Cardiovascular Sciences; University of Leicester; Leicester UK
- NIHR Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital; University of Leicester; Leicester UK
- Department of Cancer Studies, Leicester Royal Infirmary; University of Leicester; Leicester UK
| | - Toru Suzuki
- Department of Cardiovascular Sciences; University of Leicester; Leicester UK
- NIHR Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital; University of Leicester; Leicester UK
| | | | | | - Iain B. Squire
- Department of Cardiovascular Sciences; University of Leicester; Leicester UK
- NIHR Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital; University of Leicester; Leicester UK
| | - Leong L. Ng
- Department of Cardiovascular Sciences; University of Leicester; Leicester UK
- NIHR Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital; University of Leicester; Leicester UK
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Diri H, Karaca Z, Simsek Y, Tanriverdi F, Unluhizarci K, Selcuklu A, Kelestimur F. Can a glucagon stimulation test characterized by lower GH cut-off value be used for the diagnosis of growth hormone deficiency in adults? Pituitary 2015; 18:884-92. [PMID: 26129876 DOI: 10.1007/s11102-015-0666-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE The aim of this study was to assess diagnostic values of insulin tolerance test (ITT), glucagon stimulation test (GST), and insulin like growth factor-I (IGF-I) level, to find optimal GH cut-off values for GST, and to evaluate efficiencies of patient age, gender, body-mass index (BMI), and additional pituitary hormone deficiencies (PHDs) in the diagnosis of growth hormone deficiency (GHD). STUDY DESIGN This retrospective study involved 216 patients with a pituitary disease and 26 healthy controls. Age, gender, BMI, medical histories, and hormonal data including baseline and stimulated hormone values were evaluated. Three cut-off values for peak GH responses to stimulation tests were evaluated: (a) 3.00 µg/L on ITT, (b) 3.00 µg/L on GST, and (c) 1.07 µg/L on GST. RESULTS According to the ITT, GST with 3.00 µg/L cut-off, and GST with 1.07 µg/L cut-off, GHD was present in 86.1, 74.5, and 54.2 % patients, respectively. Patient age, BMI, and number of PHDs, but not gender, were found to be correlated with IGF-I and peak GH concentrations. All patients with an IGF-I concentration ≤95 ng/ml or ≥3 PHD had GHD. None of the patients with adequate GH response to the GST with 1.07 µg/L cut-off, but blunted responses to ITT and GST with 3.00 µg/L cut-off, had ≥3 PHDs. 12 out of 26 (46.2 %) healthy subjects failed the GST with 3.00 µg/L cut-off, but not with 1.07 µg/L cut-off. CONCLUSIONS Patient age, IGF-I, BMI, and number of PHDs are efficient factors associated with the diagnosis of GHD. A 4 h GST with a diagnostic GH threshold of 1.07 µg/L seems to be a good diagnostic method for GHD.
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Affiliation(s)
- Halit Diri
- Department of Endocrinology, Erciyes University Medical School, 38039, Kayseri, Turkey
| | - Zuleyha Karaca
- Department of Endocrinology, Erciyes University Medical School, 38039, Kayseri, Turkey
| | - Yasin Simsek
- Department of Endocrinology, Erciyes University Medical School, 38039, Kayseri, Turkey
| | - Fatih Tanriverdi
- Department of Endocrinology, Erciyes University Medical School, 38039, Kayseri, Turkey
| | - Kursad Unluhizarci
- Department of Endocrinology, Erciyes University Medical School, 38039, Kayseri, Turkey
| | - Ahmet Selcuklu
- Department of Neurosurgery, Erciyes University Medical School, Kayseri, Turkey
| | - Fahrettin Kelestimur
- Department of Endocrinology, Erciyes University Medical School, 38039, Kayseri, Turkey.
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Leese PT, Trang JM, Blum RA, de Groot E. An open-label clinical trial of the effects of age and gender on the pharmacodynamics, pharmacokinetics and safety of the ghrelin receptor agonist anamorelin. Clin Pharmacol Drug Dev 2015; 4:112-120. [PMID: 26640742 PMCID: PMC4657463 DOI: 10.1002/cpdd.175] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 11/04/2014] [Indexed: 12/18/2022]
Abstract
PURPOSE To assess the effect of age and gender on the pharmacokinetics (PK) of the ghrelin receptor agonist anamorelin. METHODS Three demographic cohorts of healthy subjects were enrolled in this single-center, open-label study. Subjects received a single oral dose (25 mg) of anamorelin HCl. Serial blood samples were collected over 24 hours to assess anamorelin PK and circulating growth hormone (GH) levels. Data were compared with a reference cohort. RESULTS Anamorelin was rapidly absorbed in all cohorts; peak concentrations were observed 30-45 minutes and 2-4 hours post-dose, which declined biexponentially with mean terminal half-lives of 6-7 hours. An age effect on Cmax and AUC∞ was not apparent; however, mean AUC∞ values were approximately 1.8-1.9-fold higher in the female cohorts than in the reference male cohort. GH increase was rapid and virtually identical in both sexes, though attenuated in elderly subjects. No clinically significant safety or tolerability findings were observed. CONCLUSIONS While PK parameters do suggest higher exposure in females, this effect is considered to be modest given the variability of the 6-8 subjects per cohort. Moreover, no such effect was observed in the pharmacodynamic responses, thus, dose adjustment for age and gender is considered unnecessary.
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Affiliation(s)
| | | | - Robert A Blum
- Buffalo Clinical Research Center LLC Buffalo, NY, USA
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Tan HY, Huang L, Simmons D, Veldhuis JD, Steyn FJ, Chen C. Hypothalamic distribution of somatostatin mRNA expressing neurones relative to pubertal and adult changes in pulsatile growth hormone secretion in mice. J Neuroendocrinol 2013; 25:910-9. [PMID: 23855876 DOI: 10.1111/jne.12078] [Citation(s) in RCA: 15] [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] [Received: 01/20/2013] [Revised: 07/08/2013] [Accepted: 07/11/2013] [Indexed: 01/03/2023]
Abstract
The age-associated decline in growth hormone (GH) secretion may be a consequence of the reduction in the number of GH-releasing hormone (GHRH) positive neurones. However, it remains unclear whether an alteration in the number or distribution of somatostatin (SST) neurones contributes to this change. In the present study, we characterised the role of SST in modulating the change in pulsatile GH secretion in male C57Bl/6J mice throughout puberty and into early adulthood. We assessed pulsatile GH secretion in mice at 4, 8 and 16 weeks of age. These ages correspond to early pubertal, early adulthood and adulthood, respectively. We show an elevation in peak, total and pulsatile GH secretion coinciding with periods of rapid linear growth. Using in situ hybridisation and morphometric methods, we mapped the distribution of Sst mRNA expression within the mouse brain relative to this change in pulsatile GH secretion. The results obtained show that altered pulsatile GH secretion in male mice from 4-16 weeks of age does not coincide with a significant change in the number of Sst mRNA expressing neurones or an abundance of Sst mRNA expression throughout the arcuate nucleus (ARC) and periventricular nucleus (PeV). Rather, we observed a progressive decline in Sst mRNA expressing neurones within subnuclei of the paraventricular nucleus at this time. We conclude that structural changes in Sst expression within the PeV and ARC may not reflect the observed decline in pulsatile GH secretion in mice from puberty into early adulthood.
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Affiliation(s)
- H Y Tan
- School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
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Ribeiro-Oliveira A, Abrantes MM, Barkan AL. Complex rhythmicity and age dependence of growth hormone secretion are preserved in patients with acromegaly: further evidence for a present hypothalamic control of pituitary somatotropinomas. J Clin Endocrinol Metab 2013; 98:2959-66. [PMID: 23640965 PMCID: PMC3701276 DOI: 10.1210/jc.2013-1581] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
CONTEXT Traditionally, acromegaly is viewed as a disease resulting from GH hypersecretion from an autonomous pituitary somatotropinoma. OBJECTIVE To test the hypothesis that GH secretion in acromegaly is still subjected to normal hypothalamic control, we studied the daily rhythmicity of GH secretion in normal controls and patients with newly diagnosed, untreated acromegaly. DESIGN AND SETTING This was an observational inpatient study in the General Clinical Research Center at the University of Michigan. PATIENTS OR OTHER PARTICIPANTS One hundred four normal controls and 67 acromegalic patients were included in the study. INTERVENTION The intervention consisted of frequent blood sampling over 24 hours. MAIN OUTCOME MEASURE(S) We hypothesized that acromegalic patients would show rhythmicity, sexual dimorphism, and age-related decline of GH secretion similar to normal controls. RESULTS Both normal controls and the patients exhibited 3 major GH waves with the highest values at 12:00 pm, 5:00 pm, and 1:00 am (P < .001 for all). Both controls and patients exhibited a clear appearance of the nocturnal GH waves, irrespective of the gender (P < .001 for all). The amplitude of the maximal (nocturnal) GH secretory wave (1:00 am) as compared with the nadir GH secretion (9:00 am) was clearly different between the 2 groups, with a significantly smaller magnitude in acromegaly (P < .001). A subsequent subanalysis of both groups was performed separately for both genders. Similar to the entire groups, both controls and patients exhibited a clear appearance of the nocturnal GH waves, irrespective of the gender (P < .001 for all). Patients with clearly elevated GH values have shown an age-related decline of GH secretion (r = -0.35, P < .001), similar to controls. CONCLUSIONS The analysis of GH profiles in multiple patients with untreated acromegaly discloses the persistence of the hallmarks of the central control of GH regulation, ie, nictohemeral rhythmicity, sexual dimorphism, and an age-related decline of GH output.
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Cermakian N, Lange T, Golombek D, Sarkar D, Nakao A, Shibata S, Mazzoccoli G. Crosstalk between the circadian clock circuitry and the immune system. Chronobiol Int 2013; 30:870-88. [PMID: 23697902 DOI: 10.3109/07420528.2013.782315] [Citation(s) in RCA: 185] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Various features, components, and functions of the immune system present daily variations. Immunocompetent cell counts and cytokine levels present variations according to the time of day and the sleep-wake cycle. Moreover, different immune cell types, such as macrophages, natural killer cells, and lymphocytes, contain a circadian molecular clockwork. The biological clocks intrinsic to immune cells and lymphoid organs, together with inputs from the central pacemaker of the suprachiasmatic nuclei via humoral and neural pathways, regulate the function of cells of the immune system, including their response to signals and their effector functions. Consequences of this include, for example, the daily variation in the response to an immune challenge (e.g., bacterial endotoxin injection) and the circadian control of allergic reactions. The circadian-immune connection is bidirectional, because in addition to this circadian control of immune functions, immune challenges and immune mediators (e.g., cytokines) were shown to have strong effects on circadian rhythms at the molecular, cellular, and behavioral levels. This tight crosstalk between the circadian and immune systems has wide-ranging implications for disease, as shown by the higher incidence of cancer and the exacerbation of autoimmune symptoms upon circadian disruption.
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Affiliation(s)
- Nicolas Cermakian
- Laboratory of Molecular Chronobiology, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
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Abstract
Identification of adults with GH deficiency (GHD) is challenging because clinical features of adult GHD are not distinctive and because clinical suspicion must be confirmed by biochemical tests. Adults are selected for testing for adult GHD if they have a high pretest probability of GHD, ie, if they have hypothalamic-pituitary disease, if they have received cranial irradiation or central nervous system tumor treatment, or if they survived traumatic brain injury or subarachnoid hemorrhage. Testing should only be carried out if a decision has already been made that if deficiency is found it will be treated. There are many pharmacological GH stimulation tests for the diagnosis of GHD; however, none fulfill the requirements for an ideal test having high discriminatory power; being reproducible, safe, convenient, and economical; and not being dependent on confounding factors such as age, gender, nutritional status, and in particular obesity. In obesity, GH secretion is reduced, GH clearance is enhanced, and stimulated GH secretion is reduced, causing a false-positive result. This functional hyposomatotropism in obesity is fully reversed by weight loss. In conclusion, GH stimulation tests should be avoided in obese subjects with very low pretest probability.
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Affiliation(s)
- Vera Popovic
- Department of Neuroendocrinology, Faculty of Medicine, University of Belgrade, Clinical Center Serbia, Dr Subotic 13, 11000 Belgrade, Serbia.
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Abstract
Intrinsic skin aging represents the biological clock of the skin cells per se and reflects the reduction processes that are common in internal organs. The reduced secretion of the pituitary, adrenal glands, and the gonads contributes to characteristic aging-associated body and skin phenotypes as well as behavior patterns. Our knowledge of whether there is a direct or indirect connection between hormonal deficiency and skin aging still remains limited. In females, serum levels of 17β-estradiol, dehydroepiandrosterone, progesterone, growth hormone (GH), and its downstream hormone insulin-like growth factor I (IGF-I) are significantly decreased with increasing age. In males, serum levels of GH and IGF-I decrease significantly, whereas it can decrease in late age in a part of the population. Hormones have been shown to influence skin morphology and functions, skin permeability, wound healing, sebaceous lipogenesis, and the metabolism of skin cells. Prevention of skin aging by estrogen/progesterone replacement therapy is effective if administered early after menopause and influences intrinsically aged skin only. Vitamin D substitution and antioxidant treatment may also be beneficial. Replacement therapy with androgens, GH, IGF-I, progesterone, melatonin, cortisol, and thyroid hormones still remains controversial.
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Affiliation(s)
- C C Zouboulis
- Department of Dermatology, Dessau Medical Center, Dessau, Germany.
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Mazzoccoli G, Carughi S, Greco A, De Cata A, Giuliani F, Perfetto F, Tarquini R. Neuroendocrine modulation of GH-IGF1 axis function. BIOL RHYTHM RES 2011. [DOI: 10.1080/09291016.2010.495841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
Hormones and their imbalances have significant effects on the morphology and physiology of the skin and influence various skin functions, especially wound healing and lipogenesis. With increasing age, the concentrations of important circulating hormones, including growth hormone and sex-related steroids, decrease continuously. As a result, physiologic processes are negatively influenced and various age-associated disorders may develop. As the population aged 80 and over is expected to rise in the next decades, the understanding of the molecular mechanisms accompanying skin aging and disease prevention will become even more important and play a role in preventing disease.
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Affiliation(s)
- E Makrantonaki
- Klinik für Dermatologie, Venerologie und Allergologie/Immunologisches Zentrum, Städtisches Klinikum Dessau, Auenweg 38, 06847, Dessau, Germany.
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Mazzoccoli G, Vendemiale G, Inglese M, De Cata A, Piepoli A, Pazienza V, Muscarella LA, Tarquini R. WITHDRAWN: Neuroendocrine axes function in healthy aging: Evaluation of predictive and manipulable blood serum indexes. Biomed Pharmacother 2010:S0753-3322(10)00137-X. [PMID: 20950995 DOI: 10.1016/j.biopha.2010.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2010] [Accepted: 09/05/2010] [Indexed: 12/26/2022] Open
Abstract
The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.biomag.2010.09.002. The duplicate article has therefore been withdrawn.
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Affiliation(s)
- G Mazzoccoli
- Department of Internal Medicine and Chronobiology Unit, Scientific Institute and Regional General Hospital « Casa Sollievo della Sofferenza », Cappuccini Avenue, 71013S.Giovanni Rotondo (FG),Italy
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Surya S, Horowitz JF, Goldenberg N, Sakharova A, Harber M, Cornford AS, Symons K, Barkan AL. The pattern of growth hormone delivery to peripheral tissues determines insulin-like growth factor-1 and lipolytic responses in obese subjects. J Clin Endocrinol Metab 2009; 94:2828-34. [PMID: 19470622 PMCID: PMC2730877 DOI: 10.1210/jc.2009-0638] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT It is unclear whether the pattern of GH delivery to peripheral tissues has important effects. OBJECTIVE The aim of the study was to compare the effects of pulsatile vs. continuous administration of GH upon metabolic and IGF-I parameters in obese subjects. SETTING The study was conducted at the General Clinical Research Center at the University of Michigan Medical Center. PARTICIPANTS Four men and five women with abdominal obesity (body mass index, 33 +/- 3 kg/m(2); body fat, 40 +/- 3%) participated in the study. INTERVENTION GH (0.5 mg/m(2) . d) was given iv for 3 d as: 1) continuous infusion (C); and 2) pulsatile boluses (P) (15% of the dose at 0700, 1300, and 1800 h and 55% at 2400 h). These trials were preceded by a basal period (B) when subjects received normal saline. MAIN OUTCOME MEASURES Rate of lipolysis and hepatic glucose production were evaluated using stable isotope tracer techniques. The composite index of insulin sensitivity (Matsuda index) was assessed using oral glucose tolerance test. RESULTS The increase in plasma IGF-I concentrations was greater (P < 0.05) with continuous GH infusion (211 +/- 31, 423 +/- 38, and 309 +/- 34 microg/liter for B, C, and P, respectively). Muscle IGF-I mRNA was significantly increased (P < 0.05) only after the continuous GH infusion (1.2 +/- 0.4, 4.4 +/- 1.3, and 2.3 +/- 0.6 arbitrary units, for B, C, and P, respectively). Only pulsatile GH augmented the rate of lipolysis (4.1 +/- 0.3, 4.8 +/- 0.7, and 7.1 +/- 1.1 mumol/kg . min for B, C, and P, respectively). GH had no effect on hepatic glucose production, but both modes of GH administration were equally effective in impairing insulin sensitivity. CONCLUSION These findings indicate that, in obese subjects, discrete components of GH secretory pattern may differentially affect IGF-I generation and lipolytic responses.
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Affiliation(s)
- Sowmya Surya
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, 3920 Taubman Center, Ann Arbor, MI 48109-5354, USA
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Schneider-Rivas S, Paredes-Carbajal C, Mascher D, Angoa-Pérez M, Jaramillo-Gonzaléz E, Borgonio-Pérez G, Rivas-Arancibia S. EFFECTS OF TESTOSTERONE AND GROWTH HORMONE ON LONG-TERM RETENTION AND EXTINCTION OF A PASSIVE AVOIDANCE RESPONSE IN YOUNG AND AGED RATS. Int J Neurosci 2009; 117:1443-56. [PMID: 17729155 DOI: 10.1080/00207450601125782] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Wistar rats were divided into two blocks: young and aged. Each block was then randomly divided into the following groups: (1) Control (saline solution), (2) Growth Hormone (GH), (3) Testosterone enanthate, and (4) GH plus testosterone enanthate. Animals were trained on a one-trial passive avoidance conditioning and tested for retention 24 h after training and thereafter twice a week until the extinction response occurred. Results showed that GH, testosterone, and GH plus testosterone improved long-term memory in young rats. Both GH and testosterone delayed the extinction process in young and aged rats. The GH-testosterone interaction delayed the extinction only in young rats.
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Affiliation(s)
- S Schneider-Rivas
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, México, D.F., México.
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Fanciulli G, Delitala A, Delitala G. Growth hormone, menopause and ageing: no definite evidence for 'rejuvenation' with growth hormone. Hum Reprod Update 2009; 15:341-58. [DOI: 10.1093/humupd/dmp005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Walker RF. Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? Clin Interv Aging 2008; 1:307-8. [PMID: 18046908 PMCID: PMC2699646 DOI: 10.2147/ciia.2006.1.4.307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Frutos MGS, Cacicedo L, Fernández C, Vicent D, Velasco B, Zapatero H, Sánchez-Franco F. Insights into a role of GH secretagogues in reversing the age-related decline in the GH/IGF-I axis. Am J Physiol Endocrinol Metab 2007; 293:E1140-52. [PMID: 17684105 DOI: 10.1152/ajpendo.00236.2007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Growth hormone (GH) secretion and serum insulin-like growth factor-I (IGF-I) decline with aging. This study addresses the role played by the hypothalamic regulators in the aging GH decline and investigates the mechanisms through which growth hormone secretagogues (GHS) activate GH secretion in the aging rats. Two groups of male Wistar rats were studied: young-adult (3 mo) and old (24 mo). Hypothalamic growth hormone-releasing hormone (GHRH) mRNA and immunoreactive (IR) GHRH dramatically decreased (P < 0.01 and P < 0.001) in the old rats, as did median eminence IR-GHRH. Decreases of hypothalamic IR-somatostatin (SS; P < 0.001) and SS mRNA (P < 0.01), and median eminence IR-SS were found in old rats as were GHS receptor and IGF-I mRNA (P < 0.01 and P < 0.05). Hypothalamic IGF-I receptor mRNA and protein were unmodified. Both young and old pituitary cells, cultured alone or cocultured with fetal hypothalamic cells, responded to ghrelin. Only in the presence of fetal hypothalamic cells did ghrelin elevate the age-related decrease of GH secretion to within normal adult range. In old rats, growth hormone-releasing peptide-6 returned the levels of GH and IGF-I secretion and liver IGF-I mRNA, and partially restored the lower pituitary IR-GH and GH mRNA levels to those of young untreated rats. These results suggest that the aging GH decline may result from decreased GHRH function rather than from increased SS action. The reduction of hypothalamic GHS-R gene expression might impair the action of ghrelin on GH release. The role of IGF-I is not altered. The aging GH/IGF-I axis decline could be rejuvenated by GHS treatment.
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Makrantonaki E, Zouboulis CC. William J. Cunliffe Scientific Awards. Characteristics and pathomechanisms of endogenously aged skin. Dermatology 2007; 214:352-60. [PMID: 17460411 DOI: 10.1159/000100890] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The skin, being in direct contact with several environmental factors (e.g. UV irradiation), does not only undergo endogenous aging, which has to do with the 'biological clock' of the skin cells per se, but also exogenous aging. While exogenous skin aging has been extensively studied, the pathomechanisms of endogenous skin aging remain far less clear. Endogenous skin aging reflects reduction processes, which are common in internal organs. These processes include cellular senescence and decreased proliferative capacity, decrease in cellular DNA repair capacity and chromosomal abnormalities, loss of telomeres, point mutations of extranuclear mtDNA, oxidative stress and gene mutations. As a consequence, aged skin in nonexposed areas shows typical characteristics including fine wrinkles, dryness, sallowness and loss of elasticity. Recent data have illustrated that lack of hormones occurring with age may also contribute to the aging phenotype. Improvement of epidermal skin moisture, elasticity and skin thickness, enhanced production of surface lipids, reduction of wrinkle depth, restoration of collagen fibers and increase of the collagen III/I ratio have been reported after hormone replacement therapy or local estrogen treatment in postmenopausal women. Furthermore, an in vitro model of endogenous skin aging consisting of human SZ95 sebocytes which were incubated under a hormone-substituted environment illustrated that hormones at age- and sex-specific levels were able to alter the development of cells by regulating their transcriptome. In conclusion, among other factors the hormone environment plays a distinct role in the generation of aged skin.
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Affiliation(s)
- Evgenia Makrantonaki
- Laboratory for Biogerontology, Dermato-Pharmacology and Dermato-Endocrinology, Institute of Clinical Pharmacology and Toxicology, Charité Universitatsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
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Alonso G, Sanchez-Hormigo A, Loudes C, El Yandouzi T, Carmignac D, Faivre-Bauman A, Recolin B, Epelbaum J, Robinson ICAF, Mollard P, Méry PF. Selective alteration at the growth-hormone- releasing-hormone nerve terminals during aging in GHRH-green fluorescent protein mice. Aging Cell 2007; 6:197-207. [PMID: 17328688 DOI: 10.1111/j.1474-9726.2007.00276.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Growth hormone (GH) secretion decreases spontaneously during lifespan, and the resulting GH deficiency participates in aging-related morbidity. This deficiency appears to involve a defect in the activity of hypothalamic GH-releasing hormone (GHRH) neurons. Here, we investigated this hypothesis, as well as the underlying mechanisms, in identified GHRH neurons from adult ( approximately 13 weeks old) and aged ( approximately 100 weeks old) transgenic GHRH-green fluorescent protein mice, using morphological, biochemical and electrophysiological methods. Surprisingly, the spontaneous action potential frequency was similar in adult and aged GHRH neurons studied in brain slices. This was explained by a lack of change in the intrinsic excitability, and simultaneous increases in both stimulatory glutamatergic- and inhibitory GABAergic-synaptic currents of aged GHRH neurons. Aging did not decrease GHRH and enhanced green fluorescent protein contents, GHRH neuronal number or GHRH-fibre distribution, but we found a striking enlargement of GHRH-positive axons, suggesting neuropeptide accumulation. Unlike in adults, autophagic vacuoles were evident in aged GHRH-axonal profiles using electron microscopy. Thus, GHRH neurons are involved in aging of the GH axis. Aging had a subtle effect at the nerve terminal level in GHRH neurons, contrasting with the view that neuronal aging is accompanied by more widespread damage.
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Affiliation(s)
- Gérard Alonso
- Département d'Endocrinologie, Institut de Génomique Fonctionnelle, INSERM U661, CNRS UMR 5203, Université Montpellier 1 et 2, Montpellier, France
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Abstract
Growth hormone (GH) secretion is pulsatile in nature in all species. The periodic pattern of GH release plays an important role in transmitting the GH message in a tissue-specific manner. The question of what regulates the pulsatile GH secretion pattern is an issue of not only theoretical interest but of considerable practical importance for designing different GH therapies for a variety of human diseases. This article provides a brief introductory overview of the different regulators of GH secretion and concentrates primarily on human studies.
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Affiliation(s)
- Naila Goldenberg
- Division of Metabolism, Endocrinology and Diabetes, 3920 Taubman, Box 0354, University of Michigan Medical Center, Ann Arbor, MI 48109, USA
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Kasa-Vubu JZ, Ye W, Borer KT, Rosenthal A, Meckmongkol T. Twenty-four hour growth hormone and leptin secretion in active postpubertal adolescent girls: impact of fitness, fatness, and age at menarche. J Clin Endocrinol Metab 2006; 91:3935-40. [PMID: 16868058 DOI: 10.1210/jc.2005-2841] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
CONTEXT GH is strongly related to body composition, physical activity, and pubertal progression. Adolescent girls decrease physical activity during puberty, whereas their weight increases. Because leptin is a good index of energy balance in active young women, we hypothesized that leptin is related to GH secretion in this population while taking into account fitness, fatness, and age at menarche. METHODS We measured body composition and maximal oxygen consumption (VO(2)max) in 37 postpubertal adolescent girls aged 16-21 yr. GH was sampled every 10 min and leptin hourly for 24 h. We first analyzed 6-h time blocks by repeated measures for GH and leptin, with body mass index (BMI), percent body fat, and VO(2)max as covariates for the entire group and a lean subgroup. The deconvolution method was used to characterize GH pulsatility from individual time points. RESULTS GH varied through the day (P < 0.0001), with the highest concentrations overnight. BMI, percent body fat, and VO(2)max were related to GH concentrations in the entire group, whereas leptin predicted GH in the entire group as well as the lean subgroup of girls. Higher leptin was related to lower GH concentrations (P = 0.011), regardless of time. A log leptin level increase by 1 unit decreased GH by 27%. Pulsatility characteristics showed a 1-yr increase of age at menarche increasing total GH input by 20% (P = 0.0035) independently from BMI. CONCLUSION In postpubertal adolescent girls, leptin is related to GH concentration across the lean to overweight BMI spectrum. GH pulsatile secretion was greater in girls with later age at menarche.
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Affiliation(s)
- J Z Kasa-Vubu
- Department of Pediatrics, University of Michigan Medical Center, Ann Arbor, MI 48019-0718, USA
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Grill JD, Sonntag WE, Riddle DR. Dendritic stability in a model of adult-onset IGF-I deficiency. Growth Horm IGF Res 2005; 15:337-348. [PMID: 16143551 DOI: 10.1016/j.ghir.2005.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2004] [Revised: 07/01/2005] [Accepted: 07/09/2005] [Indexed: 11/18/2022]
Abstract
OBJECTIVE A significant decrease in plasma levels of insulin-like growth factor-I (IGF-I) is one of the most robust hallmarks of aging and may contribute to functional changes associated with senescence. This study examined the role of IGF-I in the maintenance of adult dendritic morphology. DESIGN We utilized a model of the aging-related decrease in plasma IGF-I to examine whether such a decrease, in itself, leads to dendritic changes in the cerebral cortex. The dw/dw rat, originally of the Lewis strain, suffers from a spontaneous mutation in which growth hormone (GH) production is severely decreased. Since GH is responsible for the production of circulating IGF-I by the liver, these animals are deficient in plasma IGF-I. Homozygous dw/dw rats were administered porcine GH to sustain IGF-I levels during development and then GH injections were stopped as adults in order to examine the effects of adult-onset GH and IGF-I deficiency. Animals sacrificed after two or eight weeks of GH and IGF-I deficiency were compared to age-matched dw/dw animals that received GH both developmentally and throughout adulthood (GH/IGF-I replete). The dendritic arbors of pyramidal neurons in cingulate cortex were labeled by intracellular injection and reconstructed in three dimensions. RESULTS Comparing GH/IGF-I replete and deficient dw/dw rats, we found no differences in the apical or basal arbors of either layer two or layer five pyramidal neurons. CONCLUSIONS These findings indicate that a decrease in plasma levels of IGF-I is not sufficient in itself to produce dendritic changes like those seen in aging animals.
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Affiliation(s)
- Joshua D Grill
- Program in Neuroscience, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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