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Hropot T, Herman R, Janez A, Lezaic L, Jensterle M. Brown Adipose Tissue: A New Potential Target for Glucagon-like Peptide 1 Receptor Agonists in the Treatment of Obesity. Int J Mol Sci 2023; 24:ijms24108592. [PMID: 37239935 DOI: 10.3390/ijms24108592] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/01/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Adipose tissue can be divided into white adipose tissue (WAT), brown adipose tissue (BAT), and beige adipose tissue, according to the differences in morphology. WAT acts as a buffer for increased energy intake and decreased energy expenditure during the development of obesity, resulting in visceral and ectopic WAT accumulation. These WAT depots are strongly associated with chronic systemic inflammation, insulin resistance, and cardiometabolic risk related to obesity. They represent a primary weight loss target in anti-obesity management. Second-generation anti-obesity medications glucagon-like peptide-1 receptor agonists (GLP-1RAs) cause weight loss and improve body composition by reducing visceral and ectopic fat depots of WAT, resulting in improved cardiometabolic health. Recently, the understanding of the physiological significance of BAT beyond its primary function in generating heat through non-shivering thermogenesis has been expanded. This has raised scientific and pharmaceutical interest in the manipulation of BAT to further enhance weight reduction and body weight maintenance. This narrative review focuses on the potential impact of GLP-1 receptor agonism on BAT, particularly in human clinical studies. It provides an overview of the role of BAT in weight management and highlights the need for further research to elucidate the mechanisms by which GLP-1RAs affect energy metabolism and weight loss. Despite encouraging preclinical data, limited clinical evidence supports the notion that GLP-1RAs contribute to BAT activation.
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Affiliation(s)
- Tim Hropot
- Department of Pediatric Endocrinology, Diabetes and Metabolic Diseases, University Children's Hospital, 1000 Ljubljana, Slovenia
| | - Rok Herman
- Department for Endocrinology, Diabetes and Metabolic Diseases, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
- Department of Internal Medicine, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Andrej Janez
- Department for Endocrinology, Diabetes and Metabolic Diseases, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
- Department of Internal Medicine, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Luka Lezaic
- Department of Internal Medicine, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
- Department for Nuclear Medicine, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
| | - Mojca Jensterle
- Department for Endocrinology, Diabetes and Metabolic Diseases, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
- Department of Internal Medicine, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
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Jalloul W, Moscalu M, Grierosu I, Ionescu T, Stolniceanu CR, Gutu M, Ghizdovat V, Mocanu V, Azoicai D, Iliescu R, Moscalu R, Stefanescu C. Brown Adipose Tissue Biodistribution and Correlations Particularities in Parathyroid Pathology Personalized Diagnosis. Diagnostics (Basel) 2022; 12:diagnostics12123182. [PMID: 36553189 PMCID: PMC9777039 DOI: 10.3390/diagnostics12123182] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Brown adipose tissue (BAT) participates in the regulation of whole-body metabolism by producing a variety of adipokines. This study investigates into the BAT pattern and the clinical aspects of overweight and obese (OOB) vs. non-obese (NO) hyperparathyroidism (HPT) patients with the aim of assessing the impact of BAT and obesity on HPT. Parathyroid scans performed on 441 HPT patients between 2015 and 2020 were retrospectively analyzed in order to select the images with active BAT. Based on their BMI, the patients with active BAT were divided into OOB vs. NO. The results showed that BAT was present in cervical and supraclavicular regions, with a single localization especially among NO vs. multiple sites among OOB. The (total counts/pixels)BAT/(total counts/pixels)non-BAT ratio in the right cervical localization showed a significant difference between the groups with higher values in OOB. BMI, PTH, FT4, vitamin D, magnesium, creatinine, and urea had significant correlations with BAT ratios. The predictive values showed that right cervical ratios higher than 1.52 and right supraclavicular ratios lower than 1.15 indicated an increased probability of being OOB. The significant correlations between BAT activation in OOB vs. NO and HPT clinical parameters could be useful for developing potential treatments based on this tissue.
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Affiliation(s)
- Wael Jalloul
- Department of Biophysics and Medical Physics-Nuclear Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Mihaela Moscalu
- Department of Preventive Medicine and Interdisciplinarity, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
- Correspondence:
| | - Irena Grierosu
- Department of Biophysics and Medical Physics-Nuclear Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Teodor Ionescu
- Department of Biophysics and Medical Physics-Nuclear Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Cati Raluca Stolniceanu
- Department of Biophysics and Medical Physics-Nuclear Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Mihai Gutu
- Department of Biophysics and Medical Physics-Nuclear Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Vlad Ghizdovat
- Department of Biophysics and Medical Physics-Nuclear Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Veronica Mocanu
- Department of Morpho-Functional Sciences (Pathophysiology), “Grigore T. Popa” University of Medicine and Pharmacy, 16, Universitatii Street, 700115 Iasi, Romania
| | - Doina Azoicai
- Department of Epidemiology, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Radu Iliescu
- Department of Pharmacology, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iași, Romania
| | - Roxana Moscalu
- Manchester Academic Health Science Centre, Cell Matrix Biology and Regenerative Medicine, The University of Manchester, Manchester M139PT, UK
| | - Cipriana Stefanescu
- Department of Biophysics and Medical Physics-Nuclear Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
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Wang H, Wang M, Chansaenpak K, Liu Y, Yuan H, Xie J, Yin H, Branca RT, Li Z, Wu Z. A Novel PET Probe for Brown Adipose Tissue Imaging in Rodents. Mol Imaging Biol 2021; 22:675-684. [PMID: 31520279 DOI: 10.1007/s11307-019-01426-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE Brown adipose tissue (BAT) has emerged as a promising target to counteract obesity and its associated metabolic disorders. However, the detection of this tissue remains one of the major roadblocks. PROCEDURES In this study, we assess the use of BODIPY 1 as a positron emission tomography (PET) imaging agent to image BAT depots in vivo in two mouse phenotypes: obesity-resistant BALB/c mice and the obesity-prone C57BL/6 mice. [18F]BODIPY 1 is a radioactive dye that processed both radioactivity for PET imaging and fluorescence signal for in vitro mechanism study. RESULTS Through the co-staining of cancer cells with BODIPY 1 and MitoTracker, we found BODIPY 1 mainly accumulated in cell mitochondria in vitro. Fluorescence imaging of primary brown and white adipocytes further confirmed BODIPY 1 had significantly higher accumulation in primary brown adipocytes compared with primary white adipocytes. We evaluated [18F]BODIPY 1 for BAT imaging in both obesity-resistant BALB/c mice and obesity-prone C57BL/6 mice. Indeed, [18F]BODIPY 1 was efficiently taken up by BAT in both mouse genotypes (6.40 ± 1.98 %ID/g in obesity-resistant BALB/c mice (n = 8) and 5.37 ± 0.82 %ID/g in obesity-prone C57BL/6 mice (n = 7)). Although norepinephrine stimulation could increase the absolute BAT uptake, the enhancement is not significant in both genotypes (p > 0.05) at current sample size. These results suggest BAT uptake of [18F]BODIPY 1 may be independent of BAT thermogenic activity. As a comparison, 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) PET imaging was performed in obesity-resistant BALB/c mice. Significantly increased uptake was observed in adrenergically activated BAT (10.08 ± 2.52 %ID/g, n = 3) but not in inactive BAT (3.803 ± 0.70 %ID/g; n = 3). Because [18F]BODIPY 1 maintained its fluorescent property, BAT tissue was excised and studied using fluorescence microscopy. Strong fluorescence signal was observed in BAT mouse that was injected with BODIPY 1. CONCLUSIONS Unlike [18F]FDG, [18F]BODIPY 1 showed prominent accumulation in BAT under both inactive and stimulated status. [18F]BODIPY 1 may serve as a valuable BAT PET agent to possibly assess BAT mitochondria density, thus BAT thermogenic capacity after further evaluation.
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Affiliation(s)
- Hui Wang
- Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Mengzhe Wang
- Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Kantapat Chansaenpak
- Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Yang Liu
- Center for Molecular Medicine, Department of Biochemistry and Molecular Biology, The University of Georgia, Athens, GA, 30602, USA
| | - Hong Yuan
- Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.,Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jin Xie
- Department of Chemistry, Bio-Imaging Research Center, The University of Georgia, Athens, GA, 30602, USA
| | - Hang Yin
- Center for Molecular Medicine, Department of Biochemistry and Molecular Biology, The University of Georgia, Athens, GA, 30602, USA
| | - Rosa T Branca
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.,Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Zibo Li
- Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.,Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Zhanhong Wu
- Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA. .,Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
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4
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Santhanam P, Rowe SP, Solnes LB, Quainoo B, Ahima RS. A systematic review of imaging studies of human brown adipose tissue. Ann N Y Acad Sci 2021; 1495:5-23. [PMID: 33604891 DOI: 10.1111/nyas.14579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 01/25/2021] [Accepted: 01/31/2021] [Indexed: 02/06/2023]
Abstract
Brown adipose tissue (BAT) is involved in energy dissipation and has been linked to weight loss, insulin sensitivity, and reduced risk of atherosclerotic disease. BAT is found most often in the supraclavicular region, as well as mediastinal and paravertebral areas, and it is predominantly seen in young persons. BAT is activated by cold temperature and the sympathetic nervous system. In humans, BAT was initially detected via 2-deoxy-2-[18 F]fluoro-d-glucose (FDG) positron emission tomography/computed tomography (PET/CT), a high-resolution molecular imaging modality used to identify and stage malignancies. Recent studies have shown that BAT can be localized using conventional imaging modalities, such as CT or magnetic resonance imaging, as well as radiotracers used for single-photon emission CT. In this systematic review, we have summarized the evidence for BAT detection in humans using various imaging techniques.
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Affiliation(s)
- Prasanna Santhanam
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Asthma and Allergy Center, Baltimore, Maryland
| | - Steven P Rowe
- Division of Nuclear Medicine, Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Lilja B Solnes
- Division of Nuclear Medicine, Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Brittany Quainoo
- Columbian College of Arts and Sciences, George Washington University, Washington, DC
| | - Rexford S Ahima
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Asthma and Allergy Center, Baltimore, Maryland
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5
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Functional characterization of human brown adipose tissue metabolism. Biochem J 2020; 477:1261-1286. [PMID: 32271883 DOI: 10.1042/bcj20190464] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 02/07/2023]
Abstract
Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.
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6
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FDG Uptake in Brown Adipose Tissue Activated by a β3-Adrenergic Receptor Agonist Prescribed for Overactive Bladder. Clin Nucl Med 2020; 45:628-631. [PMID: 32453085 DOI: 10.1097/rlu.0000000000003078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Brown adipose tissue (BAT), which produces energy and is known to play a role as a hibernating gland, is sometimes visualized on F-FDG PET in children or in slender young adults in a cold environment. Because BAT is activated by catecholamines, FDG uptake in BAT is also observed in patients with pheochromocytoma or paraganglioma. We present the case of an elderly woman with remarkable FDG uptake in BAT. Activation of BAT by a β3-adrenergic receptor agonist (mirabegron) prescribed for overactive bladder was suspected as the cause of the marked visualization of BAT in this patient.
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7
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Frankl J, Sherwood A, Clegg DJ, Scherer PE, Öz OK. Imaging Metabolically Active Fat: A Literature Review and Mechanistic Insights. Int J Mol Sci 2019; 20:ijms20215509. [PMID: 31694216 PMCID: PMC6862590 DOI: 10.3390/ijms20215509] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 11/01/2019] [Accepted: 11/01/2019] [Indexed: 02/07/2023] Open
Abstract
Currently, obesity is one of the leading causes death in the world. Shortly before 2000, researchers began describing metabolically active adipose tissue on cancer-surveillance 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in adult humans. This tissue generates heat through mitochondrial uncoupling and functions similar to classical brown and beige adipose tissue in mice. Despite extensive research, human brown/beige fat's role in resistance to obesity in humans has not yet been fully delineated. FDG uptake is the de facto gold standard imaging technique when studying brown adipose tissue, although it has not been rigorously compared to other techniques. We, therefore, present a concise review of established and emerging methods to image brown adipose tissue activity in humans. Reviewed modalities include anatomic imaging with CT and magnetic resonance imaging (MRI); molecular imaging with FDG, fatty acids, and acetate; and emerging techniques. FDG-PET/CT is the most commonly used modality because of its widespread use in cancer imaging, but there are mechanistic reasons to believe other radiotracers may be more sensitive and accurate at detecting brown adipose tissue activity. Radiation-free modalities may help the longitudinal study of brown adipose tissue activity in the future.
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Affiliation(s)
- Joseph Frankl
- Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA; (J.F.); (A.S.)
| | - Amber Sherwood
- Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA; (J.F.); (A.S.)
| | - Deborah J. Clegg
- College of Nursing and Health Professions, Drexel University, 10th Floor, Room 1092, 1601 Cherry Street, Mail Stop 10501, Philadelphia, PA 19102, USA;
| | - Philipp E. Scherer
- Department of Internal Medicine, Touchstone Diabetes Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA;
| | - Orhan K. Öz
- Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA; (J.F.); (A.S.)
- Correspondence:
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8
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Fraum TJ, Crandall JP, Ludwig DR, Chen S, Fowler KJ, Laforest RA, Salter A, Dehdashti F, An H, Wahl RL. Repeatability of Quantitative Brown Adipose Tissue Imaging Metrics on Positron Emission Tomography with 18F-Fluorodeoxyglucose in Humans. Cell Metab 2019; 30:212-224.e4. [PMID: 31230985 DOI: 10.1016/j.cmet.2019.05.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 03/01/2019] [Accepted: 05/22/2019] [Indexed: 01/09/2023]
Abstract
Brown adipose tissue (BAT) is a promising target for anti-obesity interventions. This prospective test-retest study assessed the repeatability of several important quantitative BAT metrics. After cold activation, 24 subjects underwent positron emission tomography (PET)/computed tomography (CT) and PET/magnetic resonance imaging (MRI), utilizing 18F-fluorodeoxyglucose. Repeat imaging occurred within 14 days per an identical protocol. BAT volumes were strongly correlated between sessions for PET/CT (intraclass correlation coefficient [ICC], 0.85) and PET/MRI (ICC, 0.82). BAT maximum lean-body-mass-adjusted standardized uptake values (SULmax) were also strongly correlated between sessions for both PET/CT (ICC, 0.74) and PET/MRI (ICC, 0.83). Much longitudinal variability in BAT metrics was likely due to biological factors intrinsic to BAT, whole-body metabolic fluctuations, or temporal differences in cold-activation efficacy, rather than imaging factors. Future studies utilizing these imaging metrics to track the response BAT to interventions should incorporate this variation into sample-size considerations and response criteria.
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Affiliation(s)
- Tyler J Fraum
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - John P Crandall
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Daniel R Ludwig
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Sihao Chen
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Kathryn J Fowler
- Department of Radiology, University of California, San Diego School of Medicine, San Diego, CA, USA
| | - Richard A Laforest
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Amber Salter
- Division of Biostatistics, Washington University School of Medicine, St. Louis, MO, USA
| | - Farrokh Dehdashti
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Hongyu An
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Richard L Wahl
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA.
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Paulus A, van Ewijk PA, Nascimento EBM, De Saint-Hubert M, Hendrikx G, Vogg A, Pooters I, Schnijderberg M, Vanderlocht J, Bos G, Brans B, Schrauwen-Hinderling VB, Mottaghy FM, Bauwens M. Characterization of BAT activity in rats using invasive and non-invasive techniques. PLoS One 2019; 14:e0215852. [PMID: 31091250 PMCID: PMC6519816 DOI: 10.1371/journal.pone.0215852] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 04/09/2019] [Indexed: 11/19/2022] Open
Abstract
Introduction Brown adipose tissue (BAT) is considered as a potential target for combating obesity in humans where active BAT metabolizes glucose and fatty acids as fuel resulting in heat production. Prospective studies in humans have been set up to further study the presence and metabolic activity of BAT mostly using Positron Emission Tomography (PET) imaging in cold-stimulated conditions with the radiolabeled glucose derivative [18F]FDG. However, radiotracers beyond [18F]FDG have been proposed to investigate BAT activity, targeting various aspects of BAT metabolism. It remains questionable which tracer is best suited to detect metabolic BAT activity and to what extent those results correlate with ex vivo metabolic BAT activity. Methods PET and Single Photon Emission Computed Tomography (SPECT) imaging, targeting different aspects of BAT activation such as glucose metabolism, fatty acid metabolism, noradrenergic stimulation, blood perfusion and amino acid transport system, was performed immediately after injection of the tracer in rats under different temperatures: room temperature, acute cold (4 ⁰C for 4 h) or acclimated to cold (4 ⁰C for 6 h per day during 28 days). Furthermore, Magnetic Resonance Spectroscopy (MRS)-derived BAT temperature was measured in control and cold-acclimated rats. Results At room temperature, only [18F]FDG visualized BAT. Glucose metabolism, fatty acid metabolism, noradrenergic stimulation and blood perfusion showed a clear tracer-dependent twofold increase in BAT uptake upon cold exposure. Only the tracer for the amino acid transport system did not show BAT specific uptake under any of the experimental conditions. MRS demonstrated that cold-acclimated animals had BAT with a stronger heat-production compared to control animals. Conclusion BAT activity following cold exposure in rats was visualized by several tracers, while only [18F]FDG was also able to show BAT activity under non-stimulated conditions (room temperature). The variances in uptake of the different tracers should be taken into account when developing future clinical applications in humans.
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Affiliation(s)
- Andreas Paulus
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands
- NUTRIM School of Nutrition and Translational Research in Metabolism, Department of Nutrition and Movement Sciences, Maastricht University, Maastricht, The Netherlands
- Department of Nuclear Medicine, University Hospital RWTH Aachen University, Aachen, Germany
| | - Petronella A. van Ewijk
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands
| | - Emmani B. M. Nascimento
- NUTRIM School of Nutrition and Translational Research in Metabolism, Department of Nutrition and Movement Sciences, Maastricht University, Maastricht, The Netherlands
| | - Marijke De Saint-Hubert
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands
- CARIM, Maastricht University, Maastricht, Netherlands
| | - Geert Hendrikx
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands
- CARIM, Maastricht University, Maastricht, Netherlands
| | - Andrea Vogg
- Department of Nuclear Medicine, University Hospital RWTH Aachen University, Aachen, Germany
| | - Ivo Pooters
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands
| | - Melanie Schnijderberg
- Hematology, Department of Internal Medicine, School of Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Joris Vanderlocht
- Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Gerard Bos
- Hematology, Department of Internal Medicine, School of Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Boudewijn Brans
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands
| | - Vera B. Schrauwen-Hinderling
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands
| | - Felix M. Mottaghy
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands
- Department of Nuclear Medicine, University Hospital RWTH Aachen University, Aachen, Germany
| | - Matthias Bauwens
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands
- NUTRIM School of Nutrition and Translational Research in Metabolism, Department of Nutrition and Movement Sciences, Maastricht University, Maastricht, The Netherlands
- * E-mail:
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10
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Zoico E, Rubele S, De Caro A, Nori N, Mazzali G, Fantin F, Rossi A, Zamboni M. Brown and Beige Adipose Tissue and Aging. Front Endocrinol (Lausanne) 2019; 10:368. [PMID: 31281288 PMCID: PMC6595248 DOI: 10.3389/fendo.2019.00368] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 05/23/2019] [Indexed: 01/24/2023] Open
Abstract
Across aging, adipose tissue (AT) changes its quantity and distribution: AT becomes dysfunctional with an increase in production of inflammatory peptides, a decline of those with anti-inflammatory activity and infiltration of macrophages. Adipose organ dysfunction may lead to age-related metabolic alterations. Aging is characterized by an increase in adiposity and a decline in brown adipose tissue (BAT) depots and activity, and UCP1 expression. There are many possible links to age-associated involution of BAT, including the loss of mitochondrial function, impairment of the sympathetic nervous system, age-induced alteration of brown adipogenic stem/progenitor cell function and changes in endocrine signals. Aging is also associated with a reduction in beige adipocyte formation. Beige adipocytes are known to differentiate from a sub-population of progenitors resident in white adipose tissue (WAT); a defective ability of progenitor cells to proliferate and differentiate has been hypothesized with aging. The loss of beige adipocytes with age may be caused by changes in trophic factors in the adipose tissue microenvironment, which regulate progenitor cell proliferation and differentiation. This review focuses on possible mechanisms involved in the reduction of BAT and beige activity with aging, along with possible targets for age-related metabolic disease therapy.
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Affiliation(s)
- Elena Zoico
- Division of Geriatric Medicine, Department of Medicine, University of Verona, Verona, Italy
- *Correspondence: Elena Zoico
| | - Sofia Rubele
- Division of Geriatric Medicine, Department of Medicine, University of Verona, Verona, Italy
| | - Annamaria De Caro
- Division of Geriatric Medicine, Department of Medicine, University of Verona, Verona, Italy
| | - Nicole Nori
- Division of Geriatric Medicine, Department of Medicine, University of Verona, Verona, Italy
| | - Gloria Mazzali
- Division of Geriatric Medicine, Department of Medicine, University of Verona, Verona, Italy
| | - Francesco Fantin
- Division of Geriatric Medicine, Department of Medicine, University of Verona, Verona, Italy
| | - Andrea Rossi
- Division of Geriatric Medicine, Department of Medicine, University of Verona, Verona, Italy
| | - Mauro Zamboni
- Division of Geriatric Medicine, Department of Surgery, Dentistry, Pediatric and Gynecology, University of Verona, Verona, Italy
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Moonen MP, Nascimento EB, van Marken Lichtenbelt WD. Human brown adipose tissue: Underestimated target in metabolic disease? Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:104-112. [DOI: 10.1016/j.bbalip.2018.05.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 03/16/2018] [Accepted: 05/21/2018] [Indexed: 02/06/2023]
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Carpentier AC, Blondin DP, Virtanen KA, Richard D, Haman F, Turcotte ÉE. Brown Adipose Tissue Energy Metabolism in Humans. Front Endocrinol (Lausanne) 2018; 9:447. [PMID: 30131768 PMCID: PMC6090055 DOI: 10.3389/fendo.2018.00447] [Citation(s) in RCA: 195] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 07/20/2018] [Indexed: 12/16/2022] Open
Abstract
The demonstration of metabolically active brown adipose tissue (BAT) in humans primarily using positron emission tomography coupled to computed tomography (PET/CT) with the glucose tracer 18-fluorodeoxyglucose (18FDG) has renewed the interest of the scientific and medical community in the possible role of BAT as a target for the prevention and treatment of obesity and type 2 diabetes (T2D). Here, we offer a comprehensive review of BAT energy metabolism in humans. Considerable advances in methods to measure BAT energy metabolism, including nonesterified fatty acids (NEFA), chylomicron-triglycerides (TG), oxygen, Krebs cycle rate, and intracellular TG have led to very good quantification of energy substrate metabolism per volume of active BAT in vivo. These studies have also shown that intracellular TG are likely the primary energy source of BAT upon activation by cold. Current estimates of BAT's contribution to energy expenditure range at the lower end of what would be potentially clinically relevant if chronically sustained. Yet, 18FDG PET/CT remains the gold-standard defining method to quantify total BAT volume of activity, used to calculate BAT's total energy expenditure. Unfortunately, BAT glucose metabolism better reflects BAT's insulin sensitivity and blood flow. It is now clear that most glucose taken up by BAT does not fuel mitochondrial oxidative metabolism and that BAT glucose uptake can therefore be disconnected from thermogenesis. Furthermore, BAT thermogenesis is efficiently recruited upon repeated cold exposure, doubling to tripling its total oxidative capacity, with reciprocal reduction of muscle thermogenesis. Recent data suggest that total BAT volume may be much larger than the typically observed 50-150 ml with 18FDG PET/CT. Therefore, the current estimates of total BAT thermogenesis, largely relying on total BAT volume using 18FDG PET/CT, may underestimate the true contribution of BAT to total energy expenditure. Quantification of the contribution of BAT to energy expenditure begs for the development of more integrated whole body in vivo methods.
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Affiliation(s)
- André C. Carpentier
- Division of Endocrinology, Department of Medicine, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, QC, Canada
| | | | - Kirsi A. Virtanen
- Turku PET Centre, Turku University Hospital, Turku, Finland
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland (UEF), Kuopio, Finland
| | - Denis Richard
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, QC, Canada
| | - François Haman
- Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Éric E. Turcotte
- Department of Nuclear Medicine and Radiobiology, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, QC, Canada
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Recent advances in the detection of brown adipose tissue in adult humans: a review. Clin Sci (Lond) 2018; 132:1039-1054. [PMID: 29802209 DOI: 10.1042/cs20170276] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 03/23/2018] [Accepted: 03/23/2018] [Indexed: 02/07/2023]
Abstract
The activation of brown adipose tissue (BAT) is associated with reductions in circulating lipids and glucose in rodents and contributes to energy expenditure in humans indicating the potential therapeutic importance of targetting this tissue for the treatment of a variety of metabolic disorders. In order to evaluate the therapeutic potential of human BAT, a variety of methodologies for assessing the volume and metabolic activity of BAT are utilized. Cold exposure is often utilized to increase BAT activity but inconsistencies in the characteristics of the exposure protocols make it challenging to compare findings. The metabolic activity of BAT in response to cold exposure has most commonly been measured by static positron emission tomography of 18F-fluorodeoxyglucose in combination with computed tomography (18F-FDG PET-CT) imaging, but recent studies suggest that under some conditions this may not always reflect BAT thermogenic activity. Therefore, recent studies have used alternative positron emission tomography and computed tomography (PET-CT) imaging strategies and radiotracers that may offer important insights. In addition to PET-CT, there are numerous emerging techniques that may have utility for assessing BAT metabolic activity including magnetic resonance imaging (MRI), skin temperature measurements, near-infrared spectroscopy (NIRS) and contrast ultrasound (CU). In this review, we discuss and critically evaluate the various methodologies used to measure BAT metabolic activity in humans and provide a contemporary assessment of protocols which may be useful in interpreting research findings and guiding the development of future studies.
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Enevoldsen LH, Tindborg M, Hovmand NL, Christoffersen C, Ellingsgaard H, Suetta C, Stallknecht BM, Jennum PJ, Kjær A, Gammeltoft S. Functional brown adipose tissue and sympathetic activity after cold exposure in humans with type 1 narcolepsy. Sleep 2018; 41:4996398. [DOI: 10.1093/sleep/zsy092] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Indexed: 11/14/2022] Open
Affiliation(s)
- Lotte Hahn Enevoldsen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Denmark
| | - Marie Tindborg
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | | | - Christina Christoffersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
- Department of Clinical Biochemistry, Rigshospitalet, Denmark
| | | | - Charlotte Suetta
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Denmark
| | - Bente Merete Stallknecht
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | | | - Andreas Kjær
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
- Cluster for Molecular Imaging, Rigshospitalet and University of Copenhagen, Denmark
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Aggressive Imaging Features in a Malignant Pheochromocytoma With a Novel Mutation of the SDHB Gene. Clin Nucl Med 2018. [PMID: 28650885 DOI: 10.1097/rlu.0000000000001729] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We describe a 15-year-old boy with a huge bilateral adrenal pheochromocytoma that had a de novo germline mutation in the succinate dehydrogenase subunit B (SDHB) gene. F-FDG PET/CT revealed bilateral metabolically active large masses in the adrenal glands and the activated brown adipose tissues. The I-MIBG scintigraphic findings revealed only a mild accumulation of MIBG in the right adrenal mass, but a high uptake in the left adrenal mass. Thus, F-FDG PET/CT imaging may be more effective than I-MIBG scintigraphy for the evaluation of pheochromocytomas that are associated with highly malignant characteristics resulting from mutations of the SDHB gene.
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Chondronikola M, Beeman SC, Wahl RL. Non-invasive methods for the assessment of brown adipose tissue in humans. J Physiol 2018; 596:363-378. [PMID: 29119565 PMCID: PMC5792561 DOI: 10.1113/jp274255] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 10/04/2017] [Indexed: 01/10/2023] Open
Abstract
Brown adipose tissue (BAT) is a recently rediscovered tissue in people that has shown promise as a potential therapeutic target against obesity and its metabolic abnormalities. Reliable non-invasive assessment of BAT volume and activity is critical to allow its importance in metabolic control to be evaluated. Positron emission tomography/computed tomography (PET/CT) in combination with 2-deoxy-2-[18 F]fluoroglucose administration is currently the most frequently used and most established method for the detection and quantification of activated BAT in humans. However, it involves radiation exposure and can detect activated (e.g. after cold exposure), but not quiescent, BAT. Several alternative methods that overcome some of these limitations have been developed including different PET approaches, single-photon emission imaging, CT, magnetic resonance based approaches, contrast-enhanced ultrasound, near infrared spectroscopy, and temperature assessment of fat depots containing brown adipocytes. The purpose of this review is to summarize and critically evaluate the currently available methods that non-invasively probe various aspects of BAT biology in order to assess BAT volume and/or metabolism. Although several of these methods show promise for the non-invasive assessment of BAT volume and function, further research is needed to optimize them to enable an accurate, reproducible and practical means for the assessment of human BAT content and its metabolic function.
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Affiliation(s)
- Maria Chondronikola
- Center for Human NutritionWashington University School of MedicineSt LouisMOUSA
- Harokopio University of AthensAthensGreece
| | - Scott C. Beeman
- Department of Radiology, Mallinckrodt Institute of RadiologyWashington University School of MedicineSt LouisMOUSA
| | - Richard L. Wahl
- Department of Radiology, Mallinckrodt Institute of RadiologyWashington University School of MedicineSt LouisMOUSA
- Department of Radiation Oncology, Mallinckrodt Institute of RadiologyWashington University School of MedicineSt LouisMOUSA
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Zhang F, Hao G, Shao M, Nham K, An Y, Wang Q, Zhu Y, Kusminski CM, Hassan G, Gupta RK, Zhai Q, Sun X, Scherer PE, Oz OK. An Adipose Tissue Atlas: An Image-Guided Identification of Human-like BAT and Beige Depots in Rodents. Cell Metab 2018; 27:252-262.e3. [PMID: 29320705 PMCID: PMC5764189 DOI: 10.1016/j.cmet.2017.12.004] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/21/2017] [Accepted: 12/05/2017] [Indexed: 12/17/2022]
Abstract
[18F]Fluorodeoxyglucose-PET/CT (18F-FDG-PET/CT) imaging has been invaluable for visualizing metabolically active adipose tissues in humans with potential anti-diabetic and anti-obesity effects. To explore whether mice display human-like fat depots in anatomically comparable regions, we mapped fat depots using glucose or fatty acid imaging tracers, such as 18F-FDG through PET/CT or [123/125I]-β-methyl-p-iodophenyl-pentadecanoic acid with SPECT/CT imaging, to analogous depots in mice. Using this type of image analysis with both probes, we define a large number of additional areas of high metabolic activity corresponding to novel fat pads. Histological and gene expression analyses validate these regions as bona fide fat pads. Our findings indicate that fat depots of rodents show a high degree of topological similarity to those of humans. Studies involving both glucose and lipid tracers indicate differential preferences for these substrates in different depots and also suggest that fatty acid-based visualized approaches may reveal additional brown adipose tissue and beige depots in humans.
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Affiliation(s)
- Fang Zhang
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Guiyang Hao
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-8542, USA
| | - Mengle Shao
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kien Nham
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-8542, USA
| | - Yu An
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Qiong Wang
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yi Zhu
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Christine M Kusminski
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Gedaa Hassan
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-8542, USA
| | - Rana K Gupta
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Qiwei Zhai
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiankai Sun
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-8542, USA
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Orhan K Oz
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-8542, USA.
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Sun L, Yan J, Sun L, Velan S, Leow M. A synopsis of brown adipose tissue imaging modalities for clinical research. DIABETES & METABOLISM 2017; 43:401-410. [DOI: 10.1016/j.diabet.2017.03.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/02/2017] [Accepted: 03/27/2017] [Indexed: 12/20/2022]
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Bahler L, Holleman F, Booij J, Hoekstra JB, Verberne HJ. Hot heads & cool bodies: The conundrums of human brown adipose tissue (BAT) activity research. Eur J Intern Med 2017; 40:26-29. [PMID: 28065662 DOI: 10.1016/j.ejim.2016.12.023] [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] [Received: 09/09/2016] [Revised: 11/07/2016] [Accepted: 12/30/2016] [Indexed: 10/20/2022]
Abstract
Brown adipose tissue is able to increase energy expenditure by converting glucose and fatty acids into heat. Therefore, BAT is able to increase energy expenditure and could thereby facilitate weight loss or at least weight maintenance. Since cold is a strong activator of BAT, most prospective research is performed during cold to activate BAT. In current research, there are roughly two methods of cooling. Cooling by lowering ambient air temperature, which uses a fixed temperature for all subjects and personalized cooling, which uses cooling blankets or vests with temperatures that can be adjusted to the individual set point of shivering. These methods might trigger mechanistically different cold responses and hence result in a different BAT activation. This hypothesis is underlined by two studies with the same research question (difference in BAT activity between Caucasians and South Asians) one study found no differences in BAT activity whereas the other did found differences in BAT activity. Since most characteristics (e.g. age, BMI) were similar in the two studies, the best explanation for the differences in outcomes is the use of different cooling protocols. One of the reasons for differences in outcomes might be the sensory input from the facial skin, which might be important for the activation of BAT. In this review we will elaborate on the differences between the two cooling protocols used to activate BAT.
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Affiliation(s)
- Lonneke Bahler
- Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands.
| | - Frits Holleman
- Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Jan Booij
- Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Joost B Hoekstra
- Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Hein J Verberne
- Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands
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20
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Bahler L, Verberne H, Soeters M, Booij J, Hoekstra J, Holleman F. Dopaminergic Effects on Brown Adipose Tissue (DEBAT): A prospective physiological study. DIABETES & METABOLISM 2017; 43:172-175. [DOI: 10.1016/j.diabet.2016.06.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 06/06/2016] [Indexed: 10/21/2022]
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21
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Interobserver and intraobserver variability for the assessment of brown adipose tissue activity on 18F-FDG PET-CT. Nucl Med Commun 2016; 37:363-71. [PMID: 26599066 DOI: 10.1097/mnm.0000000000000450] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Measurement of brown adipose tissue (BAT) activity is the focus of intensive research, among others as a potential target for weight-lowering strategies. In this, BAT activity is visualized and quantified using F-fluorodeoxyglucose (F-FDG) PET-CT. The aim of this study was to determine the interobserver and intraobserver variability for detecting and quantifying BAT on F-FDG PET-CTs. METHODS Three observers retrospectively independently assessed 55 F-FDG PET-CTs (performed between April 2013 and January 2014) for BAT activity parameters: BAT volume, the maximal and mean standardized uptake value (SUVmax and SUVmean) obtained in healthy male controls. One observer reassessed the scans after 2 months for the intraobserver variability. Interobserver and intraobserver variability were expressed using Lin's concordance coefficient (LCC) and Bland-Altman plots. Correlations between the three parameters were assessed using Spearman's correlation. RESULTS The LCCs for the interobserver and intraobserver concordance for SUVmax were the highest (LCC SUVmax varied between 0.998 and 0.999, for SUVmean between 0.989 and 0.991 and for volume between 0.947 and 0.972). The Bland-Altman analysis showed a small absolute mean difference between all observers for both SUVmax and SUVmean, but the differences for volume were markedly higher. All parameters correlated statistically strongly and positively. CONCLUSION The SUVmax showed the lowest interobserver and intraobserver variation. Although SUVmean and BAT volume had a higher interobserver and intraobserver variation, the variation is still within acceptable limits. Therefore, all parameters can be used to describe BAT activity. However, for an adequate comparison between studies, we recommend the use of SUVmax.
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Contributors to Metabolic Disease Risk Following Spinal Cord Injury. CURRENT PHYSICAL MEDICINE AND REHABILITATION REPORTS 2016; 4:190-199. [PMID: 29276654 DOI: 10.1007/s40141-016-0124-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Spinal cord injury (SCI) induced changes in neurological function have significant impact on the metabolism and subsequent metabolic-related disease risk in injured individuals. This metabolic-related disease risk relationship is differential depending on the anatomic level and severity of the injury, with high level anatomic injuries contributing a greater risk of glucose and lipid dysregulation resulting in type 2 diabetes and cardiovascular disease risk elevation. Although alterations in body composition, particularly excess adiposity and its anatomical distribution in the visceral depot or ectopic location in non-adipose organs, is known to significantly contribute to metabolic disease risk, changes in fat mass and fat-free mass do not fully account for this elevated disease risk in subjects with SCI. There are other negative adaptations in body composition including reductions in skeletal muscle mass and alterations in muscle fiber type, in addition to significant reduction in physical activity, that contribute to a decline in metabolic rate and increased metabolic disease risk following SCI. Recent studies in adult humans suggest cold- and diet-induced thermogenesis through brown adipose tissue metabolism may be important for energy balance and substrate metabolism, and particularly sensitive to sympathetic nervous signaling. Considering the alterations that occur in the autonomic nervous system (SNS) (sympathetic and parasympathetic) following a SCI, significant dysfunction of brown adipose function is expected. This review will highlight metabolic alterations following SCI and integrate findings from brown adipose tissue studies as potential new areas of research to pursue.
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Bahler L, Deelen JW, Hoekstra JB, Holleman F, Verberne HJ. Seasonal influence on stimulated BAT activity in prospective trials: a retrospective analysis of BAT visualized on 18F-FDG PET-CTs and 123I-mIBG SPECT-CTs. J Appl Physiol (1985) 2016; 120:1418-23. [DOI: 10.1152/japplphysiol.00008.2016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 04/11/2016] [Indexed: 12/31/2022] Open
Abstract
Retrospective studies have shown that outdoor temperature influences the prevalence of detectable brown adipose tissue (BAT). Prospective studies use acute cold exposure to activate BAT. In prospective studies, BAT might be preconditioned in winter months leading to an increased BAT response to various stimuli. Therefore the aim of this study was to assess whether outdoor temperatures and other weather characteristics modulate the response of BAT to acute cold. To assess metabolic BAT activity and sympathetic outflow to BAT, 64 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) and 56 additional 123I- meta-iodobenzylguanidine (123I- mIBG) single-photon emission computed tomography-CT (SPECT-CT) scans, respectively, of subjects participating in previously executed trials were retrospectively included. BAT activity was measured in subjects after an overnight fast, following 2 h of cold exposure (∼17°C). The average daytime outdoor temperatures and other weather characteristics were obtained from the Dutch Royal Weather Institute. Forty-nine subjects were BAT positive. One week prior to the scan, outdoor temperature was significantly lower in the BAT-positive group compared with the BAT-negative group. Higher outdoor temperatures on preceding days resulted in lower stimulated metabolic BAT activity and volume (all P < 0.01). Outdoor temperatures did not correlate with sympathetic outflow to BAT. In conclusion, outdoor temperatures influence metabolic BAT activity and volume, but not sympathetic outflow to BAT, in subjects exposed to acute cold. To improve the consistency of the findings of future BAT studies in humans and to exclude bias introduced by outdoor temperatures, these studies should be planned in periods of similar outdoor temperatures.
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Affiliation(s)
- Lonneke Bahler
- Department of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands; and
| | - Jan W. Deelen
- Department of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands; and
| | - Joost B. Hoekstra
- Department of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands; and
| | - Frits Holleman
- Department of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands; and
| | - Hein J. Verberne
- Department of Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands
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Role of the autonomic nervous system in activation of human brown adipose tissue: A review of the literature. DIABETES & METABOLISM 2015; 41:437-45. [DOI: 10.1016/j.diabet.2015.08.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 08/21/2015] [Accepted: 08/28/2015] [Indexed: 11/17/2022]
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Bahler L, Verberne HJ, Admiraal WM, Stok WJ, Soeters MR, Hoekstra JB, Holleman F. Differences in Sympathetic Nervous Stimulation of Brown Adipose Tissue Between the Young and Old, and the Lean and Obese. J Nucl Med 2015; 57:372-7. [DOI: 10.2967/jnumed.115.165829] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/28/2015] [Indexed: 11/16/2022] Open
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26
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Can thermogenic adipocytes protect from obesity? J Physiol Biochem 2015; 71:847-53. [PMID: 26482272 DOI: 10.1007/s13105-015-0443-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 10/08/2015] [Indexed: 10/22/2022]
Abstract
The role of brown adipocytes and adipocytes of a new beige type in the energy metabolism of a healthy person and in the pathogenesis of obesity has extensively been discussed in recent years. The interest to these cells has been stimulated owing to the application of new noninvasive methods for studying the metabolic activity of tissues. Using these methods, the presence of thermogenically active adipocytes in adults and their reactivity to cold stimuli have been proved. These data, together with the results of animal experiments support the idea of thermogenic fat being a direct regulator of the energy balance of man. However, for several reasons there are some objections to this viewpoint. The main objection is that the total activity of the human thermogenic adipocytes is about 100 kJ/day, i.e., it is negligible. In addition, the burn of excessive nutrients is biologically inappropriate for an organism. Therefore, the idea that obesity is caused by the decreased activity of thermogenic adipocytes is erroneous. The statement that the causes of obesity are associated with the increased efficiency of energy-dependent processes seems more reasonable. The consequence is a reduction in energy expenditure to perform a unit of biological work. This results in excess of nutrients deposited in the form of fat.
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Hwang JJ, Yeckel CW, Gallezot JD, Aguiar RBD, Ersahin D, Gao H, Kapinos M, Nabulsi N, Huang Y, Cheng D, Carson RE, Sherwin R, Ding YS. Imaging human brown adipose tissue under room temperature conditions with (11)C-MRB, a selective norepinephrine transporter PET ligand. Metabolism 2015; 64:747-55. [PMID: 25798999 PMCID: PMC4408242 DOI: 10.1016/j.metabol.2015.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 02/11/2015] [Accepted: 03/03/2015] [Indexed: 01/20/2023]
Abstract
INTRODUCTION Brown adipose tissue (BAT) plays a critical role in adaptive thermogenesis and is tightly regulated by the sympathetic nervous system (SNS). However, current BAT imaging modalities require cold stimulation and are often unreliable to detect BAT in the basal state, at room temperature (RT). We have shown previously that BAT can be detected in rodents under both RT and cold conditions with (11)C-MRB ((S,S)-(11)C-O-methylreboxetine), a highly selective ligand for the norepinephrine transporter (NET). Here, we evaluate this novel approach for BAT detection in adult humans under RT conditions. METHODS Ten healthy, Caucasian subjects (5 M: age 24.6±2.6, BMI 21.6±2.7kg/m(2); 5 F: age 25.4±2.1, BMI 22.1±1.0kg/m(2)) underwent (11)C-MRB PET-CT imaging for cervical/supraclavicular BAT under RT and cold-stimulated conditions (RPCM Cool vest; enthalpy 15°C) compared to (18)F-FDG PET-CT imaging. Uptake of (11)C-MRB, was quantified as the distribution volume ratio (DVR) using the occipital cortex as a low NET density reference region. Total body fat and lean body mass were assessed via bioelectrical impedance analysis. RESULTS As expected, (18)F-FDG uptake in BAT was difficult to identify at RT but easily detected with cold stimulation (p=0.01). In contrast, BAT (11)C-MRB uptake (also normalized for muscle) was equally evident under both RT and cold conditions (BAT DVR: RT 1.0±0.3 vs. cold 1.1±0.3, p=0.31; BAT/muscle DVR: RT 2.3±0.7 vs. cold 2.5±0.5, p=0.61). Importantly, BAT DVR and BAT/muscle DVR of (11)C-MRB at RT correlated positively with core body temperature (r=0.76, p=0.05 and r=0.92, p=0.004, respectively), a relationship not observed with (18)F-FDG (p=0.63). Furthermore, there were gender differences in (11)C-MRB uptake in response to cold (p=0.03), which reflected significant differences in the change in (11)C-MRB as a function of both body composition and body temperature. CONCLUSIONS Unlike (18)F-FDG, the uptake of (11)C-MRB in BAT offers a unique opportunity to investigate the role of BAT in humans under basal, room temperature conditions.
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Affiliation(s)
- Janice J Hwang
- Division of Endocrinology, Yale University School of Medicine
| | | | | | | | - Devrim Ersahin
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - Hong Gao
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - Michael Kapinos
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - Nabeel Nabulsi
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - Yiyun Huang
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - David Cheng
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - Richard E Carson
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - Robert Sherwin
- Division of Endocrinology, Yale University School of Medicine
| | - Yu-Shin Ding
- Departments of Radiology and Psychiatry, New York University School of Medicine.
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28
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Abstract
Obesity is the result of disequilibrium between energy intake and energy expenditure (EE). Successful long-term weight loss is difficult to achieve with current strategies for the correction of this caloric imbalance. Non-shivering thermogenesis (NST) in brown adipose tissue (BAT) is a possible therapeutic target for the prevention and treatment of obesity and associated metabolic diseases. In recent years, more knowledge about the function and stimulation of bat has been obtained. The sympathetic nervous system (SNS) is currently seen as the main effector for brown fat function. Also, interplay between the thyroid axis and SNS plays an important role in BAT thermogenesis. Almost daily new pathways for the induction of BAT thermogenesis and 'browning' of white adipose tissue (WAT) are identified. Especially the activation of BAT via endogenous pathways has received strong scientific attention. Here we will discuss the relevance of several pathways in activating BAT and their implications for the treatment of obesity. In this review we will focus on the discussion of the most promising endocrine and paracrine pathways to stimulate BAT, by factors and pathways that naturally occur in the human body.
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Affiliation(s)
- Evie Broeders
- Department of Human Biology, NUTRIM - School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre , Maastricht , the Netherlands
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29
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Izzi-Engbeaya C, Salem V, Atkar RS, Dhillo WS. Insights into Brown Adipose Tissue Physiology as Revealed by Imaging Studies. Adipocyte 2015; 4:1-12. [PMID: 26167397 DOI: 10.4161/21623945.2014.965609] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/09/2014] [Accepted: 09/11/2014] [Indexed: 12/12/2022] Open
Abstract
There has been resurgence in interest in brown adipose tissue (BAT) following radiological and histological identification of metabolically active BAT in adult humans. Imaging enables BAT to be studied non-invasively and therefore imaging studies have contributed a significant amount to what is known about BAT function in humans. In this review the current knowledge (derived from imaging studies) about the prevalence, function, activity and regulation of BAT in humans (as well as relevant rodent studies), will be summarized.
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Key Words
- 11C-MHED, [11C]-meta-hydroxyephedrine
- 18F-FDG, [18F]-fluorodeoxyglucose
- 99mTc-sestamibi, technetium-99m sestamibi
- 99mTc-tetrofosmin, technetium-99m tetrofosmin
- ATP, adenosine triphosphate
- BAT, brown adipose tissue
- BMI, body mass index
- BOLD, blood oxygen level dependent
- CIT, cold-induced thermogenesis
- IQR, interquartile range
- MRI, magnetic resonance imaging
- NST, non-shivering thermogenesis
- PET-CT, positron emission tomography-computed tomography
- SPECT, single photon emission CT
- UCP-1, uncoupling protein 1
- WAT, white adipose tissue
- brown adipose tissue
- energy expenditure
- imaging
- metabolism
- thermogenesis
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30
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Abstract
Since 2009, the presence of brown adipose tissue (BAT) in adult humans has been irrefutably proven. It is estimated that active BAT can contribute up to 2.5-5% of resting metabolic rate in humans, suggesting that sustained activation of BAT may alleviate obesity and associated disorders. In the current chapter, the discovery of BAT in adult humans will be discussed. Furthermore, the characteristics of human BAT, methods to visualize the tissue as well as physiological and pharmacological methods to enhance its activity will be stressed.
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31
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Schopman JE, Admiraal WM, Soeters MR, Ackermans MT, Bisschop PLHT, Frier BM, Hoekstra JBL, Romijn JA, Verberne HJ, Holleman F. (18)F-fluorodeoxyglucose uptake in brown adipose tissue during insulin-induced hypoglycemia and mild cold exposure in non-diabetic adults. Metabolism 2014; 63:1280-6. [PMID: 25115550 DOI: 10.1016/j.metabol.2014.06.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 06/25/2014] [Accepted: 06/25/2014] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Hypoglycemia is associated with increased heat production and, despite of this, hypothermia. Heat production is likely to be mediated by sympathetic innervation. Brown adipose tissue is activated by cold exposure and stimulated by the sympathetic nervous system. We therefore examined the effect of hypoglycemia on uptake of the labeled glucose analogue (18)F-fluorodeoxyglucose in brown adipose tissue using positron emission tomography and computer tomography. METHODS In nine healthy adults (18)F-fluorodeoxyglucose uptake as measure of brown adipose tissue activity was assessed in a cold environment (17 °C) during euglycemia (blood glucose 4.5 mmol/L) and hypoglycemia (2.5 mmol/L) using a hyperinsulinemic glucose clamp. RESULTS Brown adipose tissue activity was observed in all participants. No difference was observed in the median (range) maximal standardized uptake values of (18)F-fluorodeoxyglucose in brown adipose tissue between euglycemia and hypoglycemia: 4.2 (1.0-7.7) versus 3.1 (2.2-12.5) g/mL (p=0.7). Similarly there were no differences in mean standardized (18)F-fluorodeoxyglucose uptake values or total brown adipose tissue volume between euglycemia and hypoglycemia. Body temperature dropped by 0.6 °C from baseline during the hypoglycemic condition and remained unchanged during the euglycemic condition. There was no correlation between the maximal standardized uptake values of (18)F-fluorodeoxyglucose in brown adipose tissue and levels of counterregulatory hormones. CONCLUSIONS This study shows that there is a similar amount of (18)F-fluorodeoxyglucose uptake in brown adipose tissue during hypoglycemia when compared to euglycemia, which makes a role for systemic catecholamines in brown adipose tissue activation and a role for brown adipose tissue thermogenesis in hypoglycemia associated hypothermia unlikely. Future studies in humans should determine whether hypoglycemia indeed increases energy expenditure, and if so which alternative source can explain this increase.
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Affiliation(s)
- Josefine E Schopman
- Department of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands.
| | - Wanda M Admiraal
- Department of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Maarten R Soeters
- Department of Endocrinology and Metabolism, Academic Medical Center, Amsterdam, The Netherlands
| | - Mariette T Ackermans
- Department of Clinical Chemistry, Laboratory of Endocrinology and Radiochemistry, Academic Medical Center, Amsterdam, The Netherlands
| | - Peter L H T Bisschop
- Department of Endocrinology and Metabolism, Academic Medical Center, Amsterdam, The Netherlands
| | - Brian M Frier
- Department of Diabetes, Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
| | - Joost B L Hoekstra
- Department of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Johannes A Romijn
- Department of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Hein J Verberne
- Department of Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Frits Holleman
- Department of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands
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32
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Bauwens M, Wierts R, van Royen B, Bucerius J, Backes W, Mottaghy F, Brans B. Molecular imaging of brown adipose tissue in health and disease. Eur J Nucl Med Mol Imaging 2014; 41:776-91. [PMID: 24509875 DOI: 10.1007/s00259-013-2611-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 10/07/2013] [Indexed: 12/25/2022]
Abstract
PURPOSE Brown adipose tissue (BAT) has transformed from an interfering tissue in oncological (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) to an independent imaging research field. This review takes the perspective from the imaging methodology on which human BAT research has come to rely on heavily. METHODS This review analyses relevant PubMed-indexed publications that discuss molecular imaging methods of BAT. In addition, reported links between BAT and human diseases such as obesity are discussed, and the possibilities for imaging in these fields are highlighted. Radiopharmaceuticals aiming at several different biological mechanisms of BAT are discussed and evaluated. RESULTS Prospective, dedicated studies allow visualization of BAT function in a high percentage of human subjects. BAT dysfunction has been implicated in obesity, linked with diabetes and associated with cachexia and atherosclerosis. Presently, (18)F-FDG PET/CT is the most useful tool for evaluating therapies aiming at BAT activity. In addition to (18)F-FDG, other radiopharmaceuticals such as (99m)Tc-sestamibi, (123)I-metaiodobenzylguanidine (MIBG), (18)F-fluorodopa and (18)F-14(R,S)-[(18)F]fluoro-6-thia-heptadecanoic acid (FTHA) may have a potential for visualizing other aspects of BAT activity. MRI methods are under continuous development and provide the prospect of functional imaging without ionizing radiation. CONCLUSION Molecular imaging of BAT can be used to quantitatively assess different aspects of BAT metabolic activity.
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Affiliation(s)
- Matthias Bauwens
- Department of Medical Imaging, Division of Nuclear Medicine, MUMC, Maastricht, Netherlands
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33
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Banzo J, Ubieto M, Berisa M, Andrés A, Mateo M, Tardín L, Parra A, Razola P, Prats E. Extensive hypermetabolic pattern of brown adipose tissue activation on 18F-FDG PET/CT in a patient diagnosed of catecholamine-secreting para-vesical paraganglioma. Rev Esp Med Nucl Imagen Mol 2013. [DOI: 10.1016/j.remnie.2013.09.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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34
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Admiraal WM, Verberne HJ, Karamat FA, Soeters MR, Hoekstra JBL, Holleman F. Cold-induced activity of brown adipose tissue in young lean men of South-Asian and European origin. Diabetologia 2013; 56:2231-7. [PMID: 23797632 DOI: 10.1007/s00125-013-2938-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 04/26/2013] [Indexed: 01/29/2023]
Abstract
AIMS/HYPOTHESIS South Asians have a disproportionately high risk of developing abdominal obesity, insulin resistance and type 2 diabetes. Brown adipose tissue (BAT) has been identified as a possible target to fight obesity and protect against metabolic disturbance. We explored whether lower BAT activity in South Asians compared with Europids may contribute to the high risk of metabolic disturbance. METHODS We studied 20 healthy men (ten Europids/ten South Asians, BMI 19-25 kg/m(2), age 18-32 years). Following 2 h of cold exposure (16-18°C) after an overnight fast, (18)F-fluorodeoxyglucose ((18)F-FDG) positron-emission tomography-computed tomography (CT) and (123)I-metaiodobenzylguanidine ((123)I-MIBG) single-photon emission computed tomography-CT were performed to visualise metabolic BAT activity and sympathetic stimulation of BAT. Metabolic BAT activity was defined as maximal standardised uptake value (SUV(max)) of (18)F-FDG, and sympathetic stimulation of BAT as semiquantitative uptake value (SQUV) of (123)I-MIBG. We performed hyperinsulinaemic-euglycaemic clamps to assess insulin sensitivity. Spearman's correlations for SUV(max) of (18)F-FDG and both SQUV of (123)I-MIBG and insulin sensitivity were determined. RESULTS The median (interquartile range) SUV(max) of (18)F-FDG in South Asians (7.5 [2.2-10.6] g/ml) was not different from the median SUV(max) obtained in Europids (4.5 [2.2-8.4] g/ml; p = 0.59). There was no correlation between BAT activity and insulin sensitivity. Correlations between SQUV of (123)I-MIBG and SUV(max) of (18)F-FDG were positive, both in the total population (ρ = 0.80, p < 0.001) and after stratification by ethnicity (Europids, ρ = 0.65, p = 0.04; South Asians, ρ = 0.83, p = 0.01). CONCLUSIONS/INTERPRETATION This is the first study to prospectively investigate ethnic differences in metabolic BAT activity during cold exposure. We did not find differences in BAT activity between South Asians and Europids. Therefore, it seems unlikely that BAT plays an important role in the development of unfavourable metabolic profiles in South Asians.
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Affiliation(s)
- W M Admiraal
- Department of Internal Medicine F4-215, Academic Medical Center, PO Box 22660, 1100DD, Amsterdam, the Netherlands,
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35
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Banzo J, Ubieto MA, Berisa MF, Andrés A, Mateo ML, Tardín L, Parra A, Razola P, Prats E. Extensive hypermetabolic pattern of brown adipose tissue activation on 18F-FDG PET/CT in a patient diagnosed of catecholamine-secreting para-vesical paraganglioma. Rev Esp Med Nucl Imagen Mol 2013; 32:397-9. [PMID: 23867638 DOI: 10.1016/j.remn.2013.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 05/15/2013] [Accepted: 05/15/2013] [Indexed: 10/26/2022]
Abstract
The widespread use of (18)F-FDG PET-CT scanning in oncological patients has allowed to demonstrate the existence of metabolically active brown fat, also called brown adipose tissue (BAT), in adult humans, and specifying its anatomical distribution in vivo. As physiological determinants to BAT (18)F-FDG uptake has been identified gender, age, temperature, and body mass index. We have observed extensive activation of the BAT, including the mesenteric region, in a patient with a catecholamine-secreting para-vesical paranganglioma. The extensive BAT activation could be secondary to adrenergic stimulation due to excess of circulating norepinephrine concentration.
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Affiliation(s)
- J Banzo
- Unidad de Medicina Nuclear, Grupo Hospitalario Quirón, La Floresta, Zaragoza, Spain.
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