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Wegmann MG, Jensen RB, Thankamony A, Frystyk J, Roche E, Hoey H, Kirk J, Shaikh G, Ivarsson SA, Söder O, Dunger DB, Juul A. Increases in Bioactive IGF do not Parallel Increases in Total IGF-I During Growth Hormone Treatment of Children Born SGA. J Clin Endocrinol Metab 2020; 105:5608612. [PMID: 31665326 DOI: 10.1210/clinem/dgz118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 10/17/2019] [Indexed: 12/16/2022]
Abstract
BACKGROUND Some children born small for gestational age (SGA) experience supra-physiological insulin-like growth factor-I (IGF-I) concentrations during GH treatment. However, measurements of total IGF-I concentrations may not reflect the bioactive fraction of IGF-I which reaches the IGF-I receptor at target organs. We examined endogenous IGF-bioactivity using an IGF-I kinase receptor activation (KIRA) assay that measures the ability of IGF-I to activate the IGF-IR in vitro. AIM To compare responses of bioactive IGF and total IGF-I concentrations in short GH treated SGA children in the North European Small for Gestational Age Study (NESGAS). MATERIAL AND METHOD In NESGAS, short SGA children (n = 101, 61 males) received GH at 67 µg/kg/day for 1 year. IGF-I concentrations were measured by Immulite immunoassay and bioactive IGF by in-house KIRA assay. RESULTS Bioactive IGF increased with age in healthy pre-pubertal children (n = 94). SGA children had low-normal bioactive IGF levels at baseline (-0.12 (1.8 SD), increasing significantly after one year of high-dose GH treatment to 1.1 (1.4) SD, P < 0.01. Following high-dose GH, 68% (n = 65) of SGA children had a total IGF-I concentration >2SD (mean IGF-I 2.8 SDS), whereas only 15% (n = 15) had levels of bioactive IGF slightly above normal reference values. At baseline, bioactive IGF (SDS) was significantly correlated to height (SDS) (r = 0.29, P = 0.005), in contrast to IGF-I (SDS) (r = 0.17, P = 0.10). IGF-I (SDS) was inversely correlated to delta height (SDS) after one year of high-dose GH treatment (r = -0.22, P = 0.02). CONCLUSION In contrast to total IGF-I concentrations, bioactive IGF stayed within the normal reference ranges for most SGA children during the first year of GH treatment.
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Affiliation(s)
| | - Rikke Beck Jensen
- Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Denmark
| | - Ajay Thankamony
- Department of Pediatrics, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Jan Frystyk
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark
- Endocrine Research Unit, Department of Endocrinology, Odense University Hospital & Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Edna Roche
- Department of Pediatrics, The National Children's Hospital, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Hilary Hoey
- Department of Pediatrics, The National Children's Hospital, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Jeremy Kirk
- Department of Endocrinology, Birmingham Children's Hospital, Birmingham, United Kingdom
| | - Guftar Shaikh
- Department of Endocrinology, Royal Hospital for Children, Glasgow, United Kingdom
| | - Sten-A Ivarsson
- Department of Clinical Sciences, Endocrine and Diabetes Unit, University of Lund, Lund, Sweden
| | - Olle Söder
- Pediatric Endocrinology Unit, Department of Women's and Children's Health, Karolinska Institute, Stockholm, Sweden
| | - David B Dunger
- Department of Pediatrics, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Anders Juul
- Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Denmark
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Mattson MP, Longo VD, Harvie M. Impact of intermittent fasting on health and disease processes. Ageing Res Rev 2017; 39:46-58. [PMID: 27810402 DOI: 10.1016/j.arr.2016.10.005] [Citation(s) in RCA: 577] [Impact Index Per Article: 82.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/26/2016] [Accepted: 10/27/2016] [Indexed: 12/22/2022]
Abstract
Humans in modern societies typically consume food at least three times daily, while laboratory animals are fed ad libitum. Overconsumption of food with such eating patterns often leads to metabolic morbidities (insulin resistance, excessive accumulation of visceral fat, etc.), particularly when associated with a sedentary lifestyle. Because animals, including humans, evolved in environments where food was relatively scarce, they developed numerous adaptations that enabled them to function at a high level, both physically and cognitively, when in a food-deprived/fasted state. Intermittent fasting (IF) encompasses eating patterns in which individuals go extended time periods (e.g., 16-48h) with little or no energy intake, with intervening periods of normal food intake, on a recurring basis. We use the term periodic fasting (PF) to refer to IF with periods of fasting or fasting mimicking diets lasting from 2 to as many as 21 or more days. In laboratory rats and mice IF and PF have profound beneficial effects on many different indices of health and, importantly, can counteract disease processes and improve functional outcome in experimental models of a wide range of age-related disorders including diabetes, cardiovascular disease, cancers and neurological disorders such as Alzheimer's disease Parkinson's disease and stroke. Studies of IF (e.g., 60% energy restriction on 2days per week or every other day), PF (e.g., a 5day diet providing 750-1100kcal) and time-restricted feeding (TRF; limiting the daily period of food intake to 8h or less) in normal and overweight human subjects have demonstrated efficacy for weight loss and improvements in multiple health indicators including insulin resistance and reductions in risk factors for cardiovascular disease. The cellular and molecular mechanisms by which IF improves health and counteracts disease processes involve activation of adaptive cellular stress response signaling pathways that enhance mitochondrial health, DNA repair and autophagy. PF also promotes stem cell-based regeneration as well as long-lasting metabolic effects. Randomized controlled clinical trials of IF versus PF and isoenergetic continuous energy restriction in human subjects will be required to establish the efficacy of IF in improving general health, and preventing and managing major diseases of aging.
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Harvie MN, Howell T. Could Intermittent Energy Restriction and Intermittent Fasting Reduce Rates of Cancer in Obese, Overweight, and Normal-Weight Subjects? A Summary of Evidence. Adv Nutr 2016; 7:690-705. [PMID: 27422504 PMCID: PMC4942870 DOI: 10.3945/an.115.011767] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Animal studies and human observational data link energy restriction (ER) to reduced rates of carcinogenesis. Most of these studies have involved continuous energy restriction (CER), but there is increasing public and scientific interest in the potential health and anticancer effects of intermittent energy restriction (IER) or intermittent fasting (IF), which comprise periods of marked ER or total fasting interspersed with periods of normal eating. This review summarizes animal studies that assessed tumor rates with IER and IF compared with CER or ad libitum feed consumption. The relevance of these animal data to human cancer is also considered by summarizing available human studies of the effects of IER or IF compared with CER on cancer biomarkers in obese, overweight, and normal-weight subjects. IER regimens that include periods of ER alternating with ad libitum feed consumption for 1, 2, or 3 wk have been reported to be superior to CER in reducing tumor rates in most spontaneous mice tumor models. Limited human data from short-term studies (≤6 mo) in overweight and obese subjects have shown that IER can lead to greater improvements in insulin sensitivity (homeostasis model assessment) than can CER, with comparable reductions in adipokines and inflammatory markers and minor changes in the insulin-like growth factor axis. There are currently no data comparing IER or IF with CER in normal-weight subjects. The benefits of IER in these short-term trials are of interest, but not sufficient evidence to recommend the use of IER above CER. Longer-term human studies of adherence to and efficacy and safety of IER are required in obese and overweight subjects, as well as normal-weight subjects.
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Affiliation(s)
- Michelle N Harvie
- Genesis Prevention Centre, University Hospital South Manchester National Health Service Foundation Trust, Manchester, United Kingdom
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Frysak Z, Schovanek J, Iacobone M, Karasek D. Insulin-like Growth Factors in a clinical setting: Review of IGF-I. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2015; 159:347-51. [PMID: 26365932 DOI: 10.5507/bp.2015.041] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/28/2015] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND AND AIMS Interest in growth hormone (GH) is inextricably linked to the need for in depth understanding of the somatomedins (insulin-like growth factors) which are polypeptides structurally similar to insulin and with broad physiological activity. To date, the most commonly known is Insulin-Like Growth Factor I (IGF-I). Despite considerable current knowledge of IGF-I, however, its bioactivity is incompletely understood. Measurement of IGF-I is of the utmost importance in the diagnosis and treatment of, for example acromegaly and growth hormone deficiency. The development of recombinant IGF-I, has allowed its use in such cases. Clinical practice, however, shows that few young/adult patients will benefit from treatment with the rIGF-I, mecasermin, given the number of adverse effects found. This review focuses on current knowledge mainly related to IGF-I and the use of its recombinant form (rIGF-I) in clinical practice. Several functions of IGI-II have been elucidated but their clinical significance is unclear.
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Affiliation(s)
- Zdenek Frysak
- Department of Internal Medicine III-Nephrology, Rheumatology and Endocrinology, University Hospital and Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic, I.P.Pavlova 6 - 779 00, - Olomouc, Czech Republic
| | - Jan Schovanek
- Department of Internal Medicine III-Nephrology, Rheumatology and Endocrinology, University Hospital and Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic, I.P.Pavlova 6 - 779 00, - Olomouc, Czech Republic
| | - Maurizio Iacobone
- Minimally Invasive Endocrine Surgery Unit, Department of Surgery, Oncology and Gastroenterology, University of Padova, Italy, Via Giustiniani 2 - 35128 - Padova, Italy
| | - David Karasek
- Department of Internal Medicine III-Nephrology, Rheumatology and Endocrinology, University Hospital and Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic, I.P.Pavlova 6 - 779 00, - Olomouc, Czech Republic
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