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Gaylord WC, Trout AT, Audino AN, Belsky JA. An International Survey Investigating the Incidence and Management of Brown Fat Uptake on 18F-FDG PET/CT at Children's Hospitals and Interventions for Mitigation. J Nucl Med Technol 2024; 52:115-120. [PMID: 38839114 DOI: 10.2967/jnmt.123.266536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/02/2023] [Indexed: 06/07/2024] Open
Abstract
Brown fat can present challenges in patients with cancer who undergo 18F-FDG PET scans. Uptake of 18F-FDG by brown fat can obscure or appear similar to active oncologic lesions, causing clinical challenges in PET interpretation. Small, retrospective studies have reported environmental and pharmacologic interventions for suppressing brown fat uptake on PET; however, there is no clear consensus on best practices. We sought to characterize practice patterns for strategies to mitigate brown fat uptake of 18F-FDG during PET scanning. Methods: A survey was developed and distributed via e-mail LISTSERV to members of the Children's Oncology Group diagnostic imaging committee, the Society for Nuclear Medicine and Molecular Imaging pediatric imaging council, and the Society of Chiefs of Radiology at Children's Hospitals between April 2022 and February 2023. Responses were stored anonymously in REDCap, aggregated, and summarized using descriptive statistics. Results: Fifty-five complete responses were submitted: 51 (93%) faculty and fellow-level physicians, 2 (4%) technologists, and 2 (4%) respondents not reporting their rank. There were 43 unique institutions represented, including 5 (12%) outside the United States. Thirty-eight of 41 (93%) institutions that responded on environmental interventions reported using warm blankets in the infusion and scanning rooms. Less than a third (n = 13, 30%) of institutions reported use of a pharmacologic intervention, with propranolol (n = 5, 38%) being most common, followed by fentanyl (n = 4, 31%), diazepam (n = 2, 15%), and diazepam plus propranolol (n = 2, 15%). Selection criteria for pharmacologic intervention varied, with the most common criterion being brown fat uptake on a prior scan (n = 6, 45%). Conclusion: Clinical practices to mitigate brown fat uptake on pediatric 18F-FDG PET vary widely. Simple environmental interventions including warm blankets or increasing the temperature of the injection and scanning rooms were not universally reported. Less than a third of institutions use pharmacologic agents for brown fat mitigation.
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Affiliation(s)
- William C Gaylord
- Department of Pediatrics, University of Tennessee Health Science Center-Chattanooga, Chattanooga, Tennessee;
- Section of Pediatric Hematology/Oncology, Children's Hospital at Erlanger, Chattanooga, Tennessee
| | - Andrew T Trout
- Department of Radiology, Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Anthony N Audino
- Nationwide Children's Hospital, Ohio State University, Columbus, Ohio
| | - Jennifer A Belsky
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana; and
- Section of Pediatric Hematology/Oncology, Riley Hospital for Children, Indianapolis, Indiana
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2
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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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3
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Brown Adipose Tissue and Its Role in Insulin and Glucose Homeostasis. Int J Mol Sci 2021; 22:ijms22041530. [PMID: 33546400 PMCID: PMC7913527 DOI: 10.3390/ijms22041530] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/21/2021] [Accepted: 02/01/2021] [Indexed: 12/15/2022] Open
Abstract
The increased worldwide prevalence of obesity, insulin resistance, and their related metabolic complications have prompted the scientific world to search for new possibilities to combat obesity. Brown adipose tissue (BAT), due to its unique protein uncoupling protein 1 (UPC1) in the inner membrane of the mitochondria, has been acknowledged as a promising approach to increase energy expenditure. Activated brown adipocytes dissipate energy, resulting in heat production. In other words, BAT burns fat and increases the metabolic rate, promoting a negative energy balance. Moreover, BAT alleviates metabolic complications like dyslipidemia, impaired insulin secretion, and insulin resistance in type 2 diabetes. The aim of this review is to explore the role of BAT in total energy expenditure, as well as lipid and glucose homeostasis, and to discuss new possible activators of brown adipose tissue in humans to treat obesity and metabolic disorders.
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Vidović V, Maksimović N, Vidović S, Damnjanović T, Novaković I. Association of PPARG rs3856806 C>T polymorphism with body mass index, glycaemia and lipid parameters in Serbian adolescents. SCRIPTA MEDICA 2021. [DOI: 10.5937/scriptamed52-29376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Background/Aim: Peroxisome proliferator-activated receptor gamma (PPARg) belongs to a family of nuclear hormone receptors and ligand-activated transcription factors. PPARG gene is expressed in many tissues including adipose tissue where it plays a crucial role in differentiation of adipocyte, insulin resistance, blood glucose levels and lipid metabolism. The aim of the study was to examine the association of rs3856806 polymorphism with the body mass index (BMI), fasting glucose levels and lipid parameters in Serbian adolescents. Methods: This research included 287 adolescents of both genders (143 boys and 144 girls), 14-15 years of age. Genotype detection was done by polymerase chain reaction-restriction fragment length polymorphism (RFLP) assay. Results: Results showed statistically significant difference in terms of fasting glucose levels among girls (p = 0.013) depending on their genotype. Female carriers of CC genotype had significantly higher level of fasting glucose levels. Also, results showed that in the group of overweight and obese girls, carriers of CT or TT genotype had statistically significant lower values of HDL cholesterol compared to girls - carriers of CC genotype (p = 0.000). However, this result was not confirmed by multiple regression analysis. Statistically significant association of rs3856806 polymorphism was not observed with BMI nor with other lipid parameters. Conclusion: This polymorphism is associated with fasting glucose level and HDL cholesterol among girls. To draw definite conclusions, further research should be conducted including non-genetic factors and other polymorphisms among this gene.
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Saari TJ, Raiko J, U-Din M, Niemi T, Taittonen M, Laine J, Savisto N, Haaparanta-Solin M, Nuutila P, Virtanen KA. Basal and cold-induced fatty acid uptake of human brown adipose tissue is impaired in obesity. Sci Rep 2020; 10:14373. [PMID: 32873825 PMCID: PMC7463032 DOI: 10.1038/s41598-020-71197-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/20/2020] [Indexed: 11/17/2022] Open
Abstract
Fatty acids (FA) are important substrates for brown adipose tissue (BAT) metabolism, however, it remains unclear whether there exists a difference in FA metabolism of BAT between lean and obese healthy humans. In this study we evaluated supraclavicular BAT fatty acid uptake (FAU) along with blood perfusion in lean and obese subjects during cold exposure and at room temperature using positron emission tomography (PET)/computed tomography (CT). Additionally, tissue samples were taken from supraclavicular region (typical BAT region) from a subset of subjects to evaluate histological presence of BAT. Non-shivering cold stress elevated FAU and perfusion of BAT in lean, but not in obese subjects. Lean subjects had greater FAU in BAT compared to obese subjects during cold exposure and interestingly also at room temperature. The higher BAT FAU was related to younger age and several indicators of superior systemic metabolic health. The subjects who manifested BAT histologically had several folds higher BAT FAU compared to subjects with no such histological manifestation. Together, obese subjects have less active tissue in supraclavicular region both in basal and cold-activated state and the FA metabolism of BAT is blunted in obesity.
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Affiliation(s)
- T J Saari
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland.,Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - J Raiko
- Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - M U-Din
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland.,Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - T Niemi
- Department of Surgery, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - M Taittonen
- Department of Anesthesiology, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - J Laine
- Department of Pathology, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - N Savisto
- Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - M Haaparanta-Solin
- Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland.,MediCity Research Laboratories, University of Turku, Tykistökatu 6A, 20520, Turku, Finland
| | - P Nuutila
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland.,Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - K A Virtanen
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland. .,Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland. .,Institute of Public Health and Clinical Nutrition, University of Eastern Finland, PL 1627, 70211, Kuopio, Finland.
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6
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Hai W, Wu X, Shi S, Yang Y, Yang Z, Li B, Xu Y, Peng J. The effects of season change and fasting on Brown adipose tissue FDG-PET in mice. Biochem Biophys Res Commun 2020; 529:398-403. [DOI: 10.1016/j.bbrc.2020.06.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 12/15/2022]
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Larson CJ. Translational Pharmacology and Physiology of Brown Adipose Tissue in Human Disease and Treatment. Handb Exp Pharmacol 2019; 251:381-424. [PMID: 30689089 DOI: 10.1007/164_2018_184] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Human brown adipose tissue (BAT) is experimentally modeled to better understand the biology of this important metabolic tissue, and also to enable the potential discovery and development of novel therapeutics for obesity and sequelae resulting from the persistent positive energy balance. This chapter focuses on translation into humans of findings and hypotheses generated in nonhuman models of BAT pharmacology. Given the demonstrated challenges of sustainably reducing caloric intake in modern humans, potential solutions to obesity likely lie in increasing energy expenditure. The energy-transforming activities of a single cell in any given tissue can be conceptualized as a flow of chemical energy from energy-rich substrate molecules into energy-expending, endergonic biological work processes through oxidative degradation of organic molecules ingested as nutrients. Despite the relatively tight coupling between metabolic reactions and products, some expended energy is incidentally lost as heat, and in this manner a significant fraction of the energy originally captured from the environment nonproductively transforms into heat rather than into biological work. In human and other mammalian cells, some processes are even completely uncoupled, and therefore purely energy consuming. These molecular and cellular actions sum up at the physiological level to adaptive thermogenesis, the endogenous physiology in which energy is nonproductively released as heat through uncoupling of mitochondria in brown fat and potentially skeletal muscle. Adaptive thermogenesis in mammals occurs in three forms, mostly in skeletal muscle and brown fat: shivering thermogenesis in skeletal muscle, non-shivering thermogenesis in brown fat, and diet-induced thermogenesis in brown fat. At the cellular level, the greatest energy transformations in humans and other eukaryotes occur in the mitochondria, where creating energetic inefficiency by uncoupling the conversion of energy-rich substrate molecules into ATP usable by all three major forms of biological work occurs by two primary means. Basal uncoupling occurs as a passive, general, nonspecific leak down the proton concentration gradient across the membrane in all mitochondria in the human body, a gradient driving a key step in ATP synthesis. Inducible uncoupling, which is the active conduction of protons across gradients through processes catalyzed by proteins, occurs only in select cell types including BAT. Experiments in rodents revealed UCP1 as the primary mammalian molecule accounting for the regulated, inducible uncoupling of BAT, and responsive to both cold and pharmacological stimulation. Cold stimulation of BAT has convincingly translated into humans, and older clinical observations with nonselective 2,4-DNP validate that human BAT's participation in pharmacologically mediated, though nonselective, mitochondrial membrane decoupling can provide increased energy expenditure and corresponding body weight loss. In recent times, however, neither beta-adrenergic antagonism nor unselective sympathomimetic agonism by ephedrine and sibutramine provide convincing evidence that more BAT-selective mechanisms can impact energy balance and subsequently body weight. Although BAT activity correlates with leanness, hypothesis-driven selective β3-adrenergic agonism to activate BAT in humans has only provided robust proof of pharmacologic activation of β-adrenergic receptor signaling, limited proof of the mechanism of increased adaptive thermogenesis, and no convincing evidence that body weight loss through negative energy balance upon BAT activation can be accomplished outside of rodents. None of the five demonstrably β3 selective molecules with sufficient clinical experience to merit review provided significant weight loss in clinical trials (BRL 26830A, TAK 677, L-796568, CL 316,243, and BRL 35135). Broader conclusions regarding the human BAT therapeutic hypothesis are limited by the absence of data from most studies demonstrating specific activation of BAT thermogenesis in most studies. Additionally, more limited data sets with older or less selective β3 agonists also did not provide strong evidence of body weight effects. Encouragingly, β3-adrenergic agonists, catechins, capsinoids, and nutritional extracts, even without robust negative energy balance outcomes, all demonstrated increased total energy expenditure that in some cases could be associated with concomitant activation of BAT, though the absence of body weight loss indicates that in no cases did the magnitude of negative energy balance reach sufficient levels. Glucocorticoid receptor agonists, PPARg agonists, and thyroid hormone receptor agonists all possess defined molecular and cellular pharmacology that preclinical models predicted to be efficacious for negative energy balance and body weight loss, yet their effects on human BAT thermogenesis upon translation were inconsistent with predictions and disappointing. A few new mechanisms are nearing the stage of clinical trials and may yet provide a more quantitatively robust translation from preclinical to human experience with BAT. In conclusion, translation into humans has been demonstrated with BAT molecular pharmacology and cell biology, as well as with physiological response to cold. However, despite pharmacologically mediated, statistically significant elevation in total energy expenditure, translation into biologically meaningful negative energy balance was not achieved, as indicated by the absence of measurable loss of body weight over the duration of a clinical study.
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Affiliation(s)
- Christopher J Larson
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.
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8
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Fuse S, Nirengi S, Amagasa S, Homma T, Kime R, Endo T, Sakane N, Matsushita M, Saito M, Yoneshiro T, Kurosawa Y, Hamaoka T. Brown adipose tissue density measured by near-infrared time-resolved spectroscopy in Japanese, across a wide age range. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-9. [PMID: 29900702 DOI: 10.1117/1.jbo.23.6.065002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 05/21/2018] [Indexed: 06/08/2023]
Abstract
F18-fluorodeoxyglucose (FDG)-positron emission tomography (PET) along with computed tomography (CT) is a standard method for assessing brown adipose tissue (BAT) activity. We tested the usefulness of near-infrared time-resolved spectroscopy (NIRTRS) as a simple and noninvasive method for evaluating BAT density (BAT-d) by examining the effects of some factors known to influence BAT activity. The total hemoglobin concentration as a parameter of BAT-d was evaluated using NIRTRS in the supraclavicular region in 413 Japanese individuals. The associations were analyzed between BAT-d and sex, age, the percentages of body fat (%BF), visceral fat (VF), and the seasonal ambient temperature (AmT) fluctuations. Age was associated with decreased BAT-d (P < 0.05). There was no sex difference in the BAT-d, except for those in their twenties. Multivariate analyses revealed that %BF and VF were correlated with BAT-d, and the lower AmT (around 4°C or 5°C) for 4 and 6 weeks prior to the measurement day was associated with an increase in the BAT-d. Our NIRTRS results were analogous to those reported with FDG18-PET / CT, indicating the usefulness of NIRTRS. BAT-d might increase during the 4 and 6 weeks after the AmT decreases to lower than 4°C or 5°C.
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Affiliation(s)
- Sayuri Fuse
- Tokyo Medical University, Department of Sports Medicine for Health Promotion, Shinjuku-ku, Tokyo, Japan
| | - Shinsuke Nirengi
- Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Division of Preven, Japan
| | - Shiho Amagasa
- Tokyo Medical University, Department of Preventive Medicine and Public Health, Shinjuku-ku, Tokyo, Japan
| | - Toshiyuki Homma
- Daito Bunka University, Faculty of Sports and Health Science, Higashimatsuyama-shi, Saitama, Japan
| | - Ryotaro Kime
- Tokyo Medical University, Department of Sports Medicine for Health Promotion, Shinjuku-ku, Tokyo, Japan
| | - Tasuki Endo
- Tokyo Medical University, Department of Sports Medicine for Health Promotion, Shinjuku-ku, Tokyo, Japan
| | - Naoki Sakane
- Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Division of Preven, Japan
| | - Mami Matsushita
- Tenshi College, Department of Nutrition, Higashi-ku, Sapporo, Japan
| | | | - Takeshi Yoneshiro
- University of California, UCSF Diabetes Center, Department of Cell and Tissue Biology, San Francisco, United States
| | - Yuko Kurosawa
- Tokyo Medical University, Department of Sports Medicine for Health Promotion, Shinjuku-ku, Tokyo, Japan
| | - Takafumi Hamaoka
- Tokyo Medical University, Department of Sports Medicine for Health Promotion, Shinjuku-ku, Tokyo, Japan
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Nishimoto Y, Tamori Y. CIDE Family-Mediated Unique Lipid Droplet Morphology in White Adipose Tissue and Brown Adipose Tissue Determines the Adipocyte Energy Metabolism. J Atheroscler Thromb 2017; 24:989-998. [PMID: 28883211 PMCID: PMC5656771 DOI: 10.5551/jat.rv17011] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
White adipose tissue (WAT) stores energy as triacylglycerol in preparation for fasting state. In contrast, brown adipose tissue (BAT) consumes energy and produces heat in a cold environment. One of the major differences between these two adipose tissues is the morphology of the intracellular lipid droplet (LD), which is large and unilocular in WAT and small and multilocular in BAT. Although the fat-specific protein 27 alpha (FSP27α), belonging to the cell death-inducing DNA fragmentation factor A (DFFA)-like effector (Cide) family, was known to be indispensable for large unilocular LD formation in WAT, the mechanism that regulated small multilocular LD formation in BAT remained unknown. We recently uncovered that FSP27β, a novel isoform of FSP27 abundantly expressed in BAT, plays a crucial role in small multilocular LD formation by inhibiting the homodimerization of CideA in BAT. We speculate that unilocular LD formation is ideal for efficient lipid storage in WAT because lipolysis from the LD surface is restricted due to the minimum LD surface area. In addition, hydrolyzed free fatty acid (FFA) and glycerol can efficiently flow out into the circulation from the cell surface. In contrast, small multilocular LD formation is ideal for efficient intracellular lipolysis from the LD surface and the subsequent facilitation of FFA transport to mitochondria that are adjacent to LDs for β-oxidation in BAT. Thus, intracellular LD morphology is closely related to the functions and characteristics of adipose tissues. Given that the browning of adipose tissue leads to enhanced energy expenditure and the prevention of obesity, clarification of the mechanism with respect to intracellular LD formation is very meaningful.
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Affiliation(s)
- Yuki Nishimoto
- Department of Internal Medicine, Division of Diabetes and Endocrinology, Kobe University Graduate School of Medicine
| | - Yoshikazu Tamori
- Department of Internal Medicine, Division of Diabetes and Endocrinology, Kobe University Graduate School of Medicine.,Department of Internal Medicine, Division of Diabetes and Endocrinology, Chibune General Hospital
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10
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Sampath SC, Sampath SC, Bredella MA, Cypess AM, Torriani M. Imaging of Brown Adipose Tissue: State of the Art. Radiology 2017; 280:4-19. [PMID: 27322970 DOI: 10.1148/radiol.2016150390] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The rates of diabetes, obesity, and metabolic disease have reached epidemic proportions worldwide. In recent years there has been renewed interest in combating these diseases not only by modifying energy intake and lifestyle factors, but also by inducing endogenous energy expenditure. This approach has largely been stimulated by the recent recognition that brown adipose tissue (BAT)-long known to promote heat production and energy expenditure in infants and hibernating mammals-also exists in adult humans. This landmark finding relied on the use of clinical fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography, and imaging techniques continue to play a crucial and increasingly central role in understanding BAT physiology and function. Herein, the authors review the origins of BAT imaging, discuss current preclinical and clinical strategies for imaging BAT, and discuss imaging methods that will provide crucial insight into metabolic disease and how it may be treated by modulating BAT activity. (©) RSNA, 2016.
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Affiliation(s)
- Srihari C Sampath
- From Musculoskeletal Biology and Bioimaging, Department of Pharmacology, Genomics Institute of the Novartis Research Foundation, San Diego, Calif (Srihari Sampath, Srinath Sampath); Division of Musculoskeletal Imaging and Intervention, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Yawkey 6E, Boston, MA 02114 (M.B., M.T.); and Translational Physiology Section, Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Md (A.M.C.)
| | - Srinath C Sampath
- From Musculoskeletal Biology and Bioimaging, Department of Pharmacology, Genomics Institute of the Novartis Research Foundation, San Diego, Calif (Srihari Sampath, Srinath Sampath); Division of Musculoskeletal Imaging and Intervention, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Yawkey 6E, Boston, MA 02114 (M.B., M.T.); and Translational Physiology Section, Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Md (A.M.C.)
| | - Miriam A Bredella
- From Musculoskeletal Biology and Bioimaging, Department of Pharmacology, Genomics Institute of the Novartis Research Foundation, San Diego, Calif (Srihari Sampath, Srinath Sampath); Division of Musculoskeletal Imaging and Intervention, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Yawkey 6E, Boston, MA 02114 (M.B., M.T.); and Translational Physiology Section, Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Md (A.M.C.)
| | - Aaron M Cypess
- From Musculoskeletal Biology and Bioimaging, Department of Pharmacology, Genomics Institute of the Novartis Research Foundation, San Diego, Calif (Srihari Sampath, Srinath Sampath); Division of Musculoskeletal Imaging and Intervention, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Yawkey 6E, Boston, MA 02114 (M.B., M.T.); and Translational Physiology Section, Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Md (A.M.C.)
| | - Martin Torriani
- From Musculoskeletal Biology and Bioimaging, Department of Pharmacology, Genomics Institute of the Novartis Research Foundation, San Diego, Calif (Srihari Sampath, Srinath Sampath); Division of Musculoskeletal Imaging and Intervention, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Yawkey 6E, Boston, MA 02114 (M.B., M.T.); and Translational Physiology Section, Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Md (A.M.C.)
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11
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Cousins J, Czachowski M, Muthukrishnan A, Currie G. Pediatric Brown Adipose Tissue on 18F-FDG PET: Diazepam Intervention. J Nucl Med Technol 2017; 45:82-86. [DOI: 10.2967/jnmt.116.187385] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 01/31/2017] [Indexed: 11/16/2022] Open
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12
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Parisi MT, Bermo MS, Alessio AM, Sharp SE, Gelfand MJ, Shulkin BL. Optimization of Pediatric PET/CT. Semin Nucl Med 2017; 47:258-274. [PMID: 28417855 DOI: 10.1053/j.semnuclmed.2017.01.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PET/CT, the most common form of hybrid imaging, has transformed oncologic imaging and is increasingly being used for nononcologic applications as well. Performing PET/CT in children poses unique challenges. Not only are children more sensitive to the effects of radiation than adults but, following radiation exposure, children have a longer postexposure life expectancy in which to exhibit adverse radiation effects. Both the PET and CT components of the study contribute to the total patient radiation dose, which is one of the most important risks of the study in this population. Another risk in children, not typically encountered in adults, is potential neurotoxicity related to the frequent need for general anesthesia in this patient population. Optimizing pediatric PET/CT requires making improvements to both the PET and the CT components of the procedure while decreasing the potential for risk. This can be accomplished through judicious performance of imaging, the use of recommended pediatric 18fluorine-2-fluoro-2-deoxy-d-glucose (18F-FDG) administered activities, thoughtful selection of pediatric-specific CT imaging parameters, careful patient preparation, and use of appropriate patient immobilization. In this article, we will review a variety of strategies for radiation dose optimization in pediatric 18F-FDG-PET/CT focusing on these processes. Awareness of and careful selection of pediatric-specific CT imaging parameters designed for appropriate diagnostic, localization, or attenuation correction only CT, in conjunction with the use of recommended radiotracer administered activities, will help to ensure image quality while limiting patient radiation exposure. Patient preparation, an important determinant of image quality, is another focus of this review. Appropriate preparative measures are even more crucial in children in whom there is a higher incidence of brown fat, which can interfere with study interpretation. Finally, we will discuss measures to improve the patient experience, the resource use, the departmental workflow, and the diagnostic performance of the study through the use of appropriate technology, all in the context of minimizing procedure-related risks.
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Affiliation(s)
- Marguerite T Parisi
- Departments of Radiology, University of Washington School of Medicine, Seattle Children's Hospital, Seattle, WA; Departments of Pediatrics, University of Washington School of Medicine and Seattle Children's Hospital, Seattle, WA.
| | - Mohammed S Bermo
- Department of Nuclear Medicine, University of Washington School of Medicine, Seattle, WA
| | - Adam M Alessio
- Departments of Radiology, University of Washington School of Medicine, Seattle Children's Hospital, Seattle, WA
| | - Susan E Sharp
- Departments of Radiology, University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinatti, OH
| | - Michael J Gelfand
- Departments of Radiology, University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinatti, OH
| | - Barry L Shulkin
- Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN
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Pelegrí Martínez L, Kohan AA, Vercher Conejero JL. Optimization of the protocols for the use of contrast agents in PET/CT studies. RADIOLOGIA 2016; 59:64-74. [PMID: 27726860 DOI: 10.1016/j.rx.2016.07.004] [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: 12/20/2015] [Revised: 06/27/2016] [Accepted: 07/05/2016] [Indexed: 10/20/2022]
Abstract
The introduction of PET/CT scanners in clinical practice in 1998 has improved care for oncologic patients throughout the clinical pathway, from the initial diagnosis of disease through the evaluation of the response to treatment to screening for possible recurrence. The CT component of a PET/CT study is used to correct the attenuation of PET studies; CT also provides anatomic information about the distribution of the radiotracer. CT is especially useful in situations where PET alone can lead to false positives and false negatives, and CT thereby improves the diagnostic performance of PET. The use of intravenous or oral contrast agents and optimal CT protocols have improved the detection and characterization of lesions. However, there are circumstances in which the systematic use of contrast agents is not justified. The standard acquisition in PET/CT scanners is the whole body protocol, but this can lead to artifacts due to the position of patients and respiratory movements between the CT and PET acquisitions. This article discusses these aspects from a constructive perspective with the aim of maximizing the diagnostic potential of PET/CT and providing better care for patients.
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Affiliation(s)
- L Pelegrí Martínez
- Servei de Diagnòstic per la Imatge, Hospital Sant Joan Despí-Moisès Broggi, Sant Joan Despí (Barcelona), España.
| | - A A Kohan
- Servicio de Radiología, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina
| | - J L Vercher Conejero
- Unitat PET-TC IDI, Hospital Universitari de Bellvitge, Institut d'Investigació Biomédica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat (Barcelona), España
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14
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Abstract
Human brown adipose tissue has been acknowledged in newborns and children but in adults the first printed publications are from the beginning of 20th century. Further evidence of the existence of adult brown fat was published throughout the century but only very recently the functionality of active brown adipose tissue in vivo in adulthood was confirmed. This was contributed mainly by advanced imaging technology, namely hybrid positron emission tomography (PET) and computed tomography (CT), being able to combine functional and anatomical imaging data. Functionality is most commonly measured with glucose analog, 18F-fluoro-2-deoxy-d-glucose (FDG) but other tracers for other functions than glucose uptake have been introduced as well. Growing body of evidence has increased the knowledge of the role of brown adipose tissue in human metabolism and energy expenditure, providing a promising option for the management of body weight balance and disturbed glucose and lipid metabolism.
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Affiliation(s)
- Kirsi A Virtanen
- Turku PET Centre, Turku University Hospital and University of Turku, Kiinamyllynkatu 4-8, 20520 Turku, Finland.
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15
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Thuzar M, Ho KKY. MECHANISMS IN ENDOCRINOLOGY: Brown adipose tissue in humans: regulation and metabolic significance. Eur J Endocrinol 2016; 175:R11-25. [PMID: 27220620 DOI: 10.1530/eje-15-1217] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/09/2016] [Indexed: 01/14/2023]
Abstract
The recent discovery that functional brown adipose tissue (BAT) persists in adult humans has enkindled a renaissance in metabolic research, with a view of harnessing its thermogenic capacity to combat obesity. This review focuses on the advances in the regulation and the metabolic significance of BAT in humans. BAT activity in humans is stimulated by cold exposure and by several factors such as diet and metabolic hormones. BAT function is regulated at two levels: an acute process involving the stimulation of the intrinsic thermogenic activity of brown adipocytes and a chronic process of growth involving the proliferation of pre-existing brown adipocytes or differentiation to brown adipocytes of adipocytes from specific white adipose tissue depots. BAT activity is reduced in the obese, and its stimulation by cold exposure increases insulin sensitivity and reduces body fat. These observations provide strong evidence that BAT plays a significant role in energy balance in humans and has the potential to be harnessed as a therapeutic target for the management of obesity.
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Affiliation(s)
- Moe Thuzar
- Department of Endocrinology and DiabetesPrincess Alexandra Hospital, Brisbane, Queensland, AustraliaSchool of MedicineUniversity of Queensland, Brisbane, Queensland 4102, Australia Department of Endocrinology and DiabetesPrincess Alexandra Hospital, Brisbane, Queensland, AustraliaSchool of MedicineUniversity of Queensland, Brisbane, Queensland 4102, Australia
| | - Ken K Y Ho
- Department of Endocrinology and DiabetesPrincess Alexandra Hospital, Brisbane, Queensland, AustraliaSchool of MedicineUniversity of Queensland, Brisbane, Queensland 4102, Australia Department of Endocrinology and DiabetesPrincess Alexandra Hospital, Brisbane, Queensland, AustraliaSchool of MedicineUniversity of Queensland, Brisbane, Queensland 4102, Australia
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16
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The Values and Limitations of FDG-PET/CT for Diagnosis of Hibernoma. Case Rep Orthop 2015; 2015:958690. [PMID: 26783480 PMCID: PMC4691481 DOI: 10.1155/2015/958690] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Accepted: 11/23/2015] [Indexed: 02/07/2023] Open
Abstract
Hibernoma is a rare benign lipogenic tumor of brown fat that develops in a wide variety of locations. Although the features of hibernoma demonstrated by MRI resemble those of liposarcoma, recent FDG-PET/CT studies have documented higher radiotracer uptake than liposarcoma, suggesting that FDG/PET/CT is useful for differentiating hibernoma from liposarcoma. Here we report two cases of hibernoma that showed relatively lower SUVs than those reported previously, lying within the range for liposarcoma. Our findings emphasize that hibernoma needs to be included in the differential diagnosis of any fat-containing tumor showing intense accumulation by FDG-PET/CT. Although it is unlikely that such a rare condition could be reasonably diagnosed on the basis of MRI and FDG-PET/CT alone due to possible SUV overlap between hibernoma and liposarcoma, it is important to recognize this extremely rare lipogenic tumor for accurate diagnosis and appropriate management.
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17
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Abstract
Brown adipose tissue (BAT) is the major site of sympathetically activated adaptive thermogenesis during cold exposure and after spontaneous hyperphagia, thereby controlling whole-body energy expenditure and body fat. Recent radionuclide studies have demonstrated the existence of metabolically active BAT in healthy adult humans. Human BAT is activated by acute cold exposure, being positively correlated to cold-induced increases in energy expenditure. The metabolic activity of BAT is lower in older and obese individuals. The inverse relationship between the BAT activity and body fatness suggests that BAT, because of its energy dissipating activity, is protective against body fat accumulation. In fact, either repeated cold exposure or daily ingestion of some food ingredients acting on transient receptor potential channels recruited BAT in association with increased energy expenditure and decreased body fat even in individuals with low BAT activities before the treatment. Thus, BAT is a promising therapeutic target for combating human obesity and related metabolic disorders.
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18
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Rockstroh D, Landgraf K, Wagner IV, Gesing J, Tauscher R, Lakowa N, Kiess W, Bühligen U, Wojan M, Till H, Blüher M, Körner A. Direct evidence of brown adipocytes in different fat depots in children. PLoS One 2015; 10:e0117841. [PMID: 25706927 PMCID: PMC4338084 DOI: 10.1371/journal.pone.0117841] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 01/02/2015] [Indexed: 12/31/2022] Open
Abstract
Recent studies suggested the persistence of brown adipocytes in adult humans, as opposed to being exclusively present in infancy. In this study, we investigated the presence of brown-like adipocytes in adipose tissue (AT) samples of children and adolescents aged 0 to 18 years and evaluated the association with age, location, and obesity. For this, we analysed AT samples from 131 children and 23 adults by histological, immunohistochemical and expression analyses. We detected brown-like and UCP1 positive adipocytes in 10.3% of 87 lean children (aged 0.3 to 10.7 years) and in one overweight infant, whereas we did not find brown adipocytes in obese children or adults. In our samples, the brown-like adipocytes were interspersed within white AT of perirenal, visceral and also subcutaneous depots. Samples with brown-like adipocytes showed an increased expression of UCP1 (>200fold), PRDM16 (2.8fold), PGC1α and CIDEA while other brown/beige selective markers, such as PAT2, P2RX5, ZIC1, LHX8, TMEM26, HOXC9 and TBX1 were not significantly different between UCP1 positive and negative samples. We identified a positive correlation between UCP1 and PRDM16 within UCP1 positive samples, but not with any other brown/beige marker. In addition, we observed significantly increased PRDM16 and PAT2 expression in subcutaneous and visceral AT samples with high UCP1 expression in adults. Our data indicate that brown-like adipocytes are present well beyond infancy in subcutaneous depots of non-obese children. The presence was not restricted to typical perirenal locations, but they were also interspersed within WAT of visceral and subcutaneous depots.
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MESH Headings
- Adipocytes/cytology
- Adipocytes/metabolism
- Adipocytes, Brown/cytology
- Adipocytes, Brown/metabolism
- Adipose Tissue, Brown/cytology
- Adipose Tissue, Brown/metabolism
- Adipose Tissue, White/cytology
- Adipose Tissue, White/metabolism
- Adolescent
- Adult
- Amino Acid Transport Systems, Neutral/genetics
- Amino Acid Transport Systems, Neutral/metabolism
- Body Mass Index
- Child
- Child, Preschool
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Female
- Humans
- Immunohistochemistry
- Infant
- Infant, Newborn
- Intra-Abdominal Fat/cytology
- Intra-Abdominal Fat/metabolism
- Ion Channels/genetics
- Ion Channels/metabolism
- Male
- Mitochondrial Proteins/genetics
- Mitochondrial Proteins/metabolism
- Obesity
- Overweight
- Reverse Transcriptase Polymerase Chain Reaction
- Subcutaneous Fat/cytology
- Subcutaneous Fat/metabolism
- Symporters/genetics
- Symporters/metabolism
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Uncoupling Protein 1
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Affiliation(s)
- Denise Rockstroh
- Center for Pediatric Research Leipzig, University Hospital for Children & Adolescents, Department of Women’s and Child Health, University of Leipzig, Leipzig, Germany
- Integrated Research and Treatment Center (IFB), University of Leipzig, Leipzig, Germany
| | - Kathrin Landgraf
- Center for Pediatric Research Leipzig, University Hospital for Children & Adolescents, Department of Women’s and Child Health, University of Leipzig, Leipzig, Germany
- Integrated Research and Treatment Center (IFB), University of Leipzig, Leipzig, Germany
| | - Isabel Viola Wagner
- Center for Pediatric Research Leipzig, University Hospital for Children & Adolescents, Department of Women’s and Child Health, University of Leipzig, Leipzig, Germany
| | - Julia Gesing
- Center for Pediatric Research Leipzig, University Hospital for Children & Adolescents, Department of Women’s and Child Health, University of Leipzig, Leipzig, Germany
| | - Roy Tauscher
- Center for Pediatric Research Leipzig, University Hospital for Children & Adolescents, Department of Women’s and Child Health, University of Leipzig, Leipzig, Germany
| | - Nicole Lakowa
- Integrated Research and Treatment Center (IFB), University of Leipzig, Leipzig, Germany
- Department of Medicine, Division of Endocrinology, University of Leipzig, Leipzig, Germany
| | - Wieland Kiess
- Center for Pediatric Research Leipzig, University Hospital for Children & Adolescents, Department of Women’s and Child Health, University of Leipzig, Leipzig, Germany
| | - Ulf Bühligen
- Department of Pediatric Surgery, University of Leipzig, Leipzig, Germany
| | - Magdalena Wojan
- Department of Orthopaedic Surgery, University of Leipzig, Leipzig, Germany
| | - Holger Till
- Integrated Research and Treatment Center (IFB), University of Leipzig, Leipzig, Germany
- Department of Pediatric and Adolescent Surgery, Medical University Graz, Graz, Austria
| | - Matthias Blüher
- Integrated Research and Treatment Center (IFB), University of Leipzig, Leipzig, Germany
- Department of Medicine, Division of Endocrinology, University of Leipzig, Leipzig, Germany
| | - Antje Körner
- Center for Pediatric Research Leipzig, University Hospital for Children & Adolescents, Department of Women’s and Child Health, University of Leipzig, Leipzig, Germany
- Integrated Research and Treatment Center (IFB), University of Leipzig, Leipzig, Germany
- * E-mail: (AK)
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19
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Sidossis L, Kajimura S. Brown and beige fat in humans: thermogenic adipocytes that control energy and glucose homeostasis. J Clin Invest 2015; 125:478-86. [PMID: 25642708 DOI: 10.1172/jci78362] [Citation(s) in RCA: 487] [Impact Index Per Article: 54.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Brown adipose tissue (BAT), a specialized fat that dissipates energy to produce heat, plays an important role in the regulation of energy balance. Two types of thermogenic adipocytes with distinct developmental and anatomical features exist in rodents and humans: classical brown adipocytes and beige (also referred to as brite) adipocytes. While classical brown adipocytes are located mainly in dedicated BAT depots of rodents and infants, beige adipocytes sporadically reside with white adipocytes and emerge in response to certain environmental cues, such as chronic cold exposure, a process often referred to as "browning" of white adipose tissue. Recent studies indicate the existence of beige adipocytes in adult humans, making this cell type an attractive therapeutic target for obesity and obesity-related diseases, including type 2 diabetes. This Review aims to cover recent progress in our understanding of the anatomical, developmental, and functional characteristics of brown and beige adipocytes and discuss emerging questions, with a special emphasis on adult human BAT.
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20
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Abstract
Positron emission tomography combined with computed tomography (PET/CT) has emerged in the last decade as a dominant imaging modality used for staging, monitoring response and surveillance of various cancers, including melanoma. Using 2-deoxy-2-((18)F)fluoro-D-glucose ((18)F-FDG) as the radiopharmaceutical, PET/CT has demonstrated its efficacy and its utility in the management of patients with advanced melanoma. Nonetheless, challenges remain in the early stage evaluation of melanoma and in the development of novel radiotracers to better characterize lesions found on PET/CT. This chapter focuses on the advantages and limitations of this imaging modality in melanoma. We also detail and describe the approach to perform (18)F-FDG PET/CT, the methods to accurately quantify lesions, as well as the pearls/pitfalls of image interpretation. Finally, an overview of preclinical and investigational clinical radiopharmaceuticals is presented.
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Affiliation(s)
- Khun Visith Keu
- Département de Radiobiologie et de Médecine Nucléaire, Université de Sherbrooke, Sherbrooke, Québec, Canada
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21
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Sopena Novales P, Plancha Mansanet M, Martinez Carsi C, Sopena Monforte R. Medicina nuclear y radiofármacos. RADIOLOGIA 2014; 56 Suppl 1:29-37. [DOI: 10.1016/j.rx.2014.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 06/18/2014] [Accepted: 07/02/2014] [Indexed: 11/25/2022]
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22
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23
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Agrawal A, Kembhavi S, Purandare N, Shah S, Rangarajan V. Report of two cases of fluorodeoxyglucose positron emission tomography/computed tomography appearance of hibernoma: A rare benign tumor. Indian J Nucl Med 2014; 29:40-2. [PMID: 24591783 PMCID: PMC3928751 DOI: 10.4103/0972-3919.125773] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
False-positive findings are commonly seen in positron emission tomography computed tomography imaging. One of the most common false positive finding is uptake of fluorodeoxyglucose in brown adipose tissue. Herein, we report two cases with incidentally detected hibernomas-a brown fat containing tumor with metabolic activity.
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Affiliation(s)
- Archi Agrawal
- Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India
| | - Seema Kembhavi
- Department of Radiology, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India
| | - Nilendu Purandare
- Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India
| | - Sneha Shah
- Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India
| | - Venkatesh Rangarajan
- Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India
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24
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Sacks H, Symonds ME. Anatomical locations of human brown adipose tissue: functional relevance and implications in obesity and type 2 diabetes. Diabetes 2013; 62:1783-90. [PMID: 23704519 PMCID: PMC3661606 DOI: 10.2337/db12-1430] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We will review information about and present hypotheses as to the anatomy of brown adipose tissue (BAT). Why is it located where it is in humans? Its anatomical distribution is likely to confer survival value by protecting critical organs from hypothermia by adaptive thermogenesis. Ultimately, the location and function will be important when considering therapeutic strategies for preventing and treating obesity and type 2 diabetes, in which case successful interventions will need to have a significant effect on BAT function in subjects living in a thermoneutral environment. In view of the diverse locations and potential differences in responsiveness between BAT depots, it is likely that BAT will be shown to have much more subtle and thus previously overlooked functions and regulatory control mechanisms.
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Affiliation(s)
- Harold Sacks
- Endocrinology and Diabetes Division, VA Greater Los Angeles Healthcare System, Los Angeles, California, USA.
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25
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Abstract
Brown adipose tissue (BAT) is recognized as the major site of sympathetically activated nonshivering thermogenesis during cold exposure and after spontaneous hyperphagia, thereby controling whole-body energy expenditure and body fat. In adult humans, BAT has long been believed to be absent or negligible, but recent studies using fluorodeoxyglucose-positron emission tomography, in combination with computed tomography, demonstrated the existence of metabolically active BAT in healthy adult humans. Human BAT is activated by acute cold exposure, being positively correlated to cold-induced increases in energy expenditure. The metabolic activity of BAT differs among individuals, being lower in older and obese individuals. Thus, BAT is recognized as a regulator of whole-body energy expenditure and body fat in humans as in small rodents, and a hopeful target combating obesity and related disorders. In fact, there are some food ingredients such as capsaicin and capsinoids, which have potential to activate and recruit BAT via activity on the specific receptor, transient receptor potential channels, thereby increasing energy expenditure and decreasing body fat modestly and consistently.
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26
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Abstract
Brown adipose tissue (BAT) was thought to disappear after infancy. Recent findings of BAT in patients undergoing positron emission tomography/computed tomography (PET/CT) have renewed the interest in deciphering the relevance of this tissue in humans. Available data suggest that BAT is more prevalent in children than in adults and that its activation during adolescence is associated with significantly lower gains in weight and adiposity. Data also show that pediatric patients with metabolically active BAT on PET/CT examinations have significantly greater muscle volume than patients without identifiable BAT. Both the activity and the amount of BAT increase during puberty. The magnitude of the increase is higher in boys as compared with girls and is closely related to gains in muscle volume. Hence, concurrent with the gains in skeletal muscle during infancy and puberty, all infants and adolescents accumulate large amounts of BAT. These observations are consistent with in vitro investigations suggesting close interactions between brown adipocytes, white adipocytes, and myocytes. In this review, we discuss the potential role of this tissue in regulating weight and musculoskeletal development in children.
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Affiliation(s)
- Vicente Gilsanz
- Department of Radiology, Children's Hospital Los Angeles, Los Angeles, CA, USA.
| | - Houchun H. Hu
- Department of Radiology, Children’s Hospital Los Angeles, Los Angeles, CA 90027
,Department of Electrical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90027
| | - Shingo Kajimura
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143
,Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143
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27
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Wang X, Minze LJ, Shi ZZ. Functional imaging of brown fat in mice with 18F-FDG micro-PET/CT. J Vis Exp 2012. [PMID: 23207798 DOI: 10.3791/4060] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Brown adipose tissue (BAT) differs from white adipose tissue (WAT) by its discrete location and a brown-red color due to rich vascularization and high density of mitochondria. BAT plays a major role in energy expenditure and non-shivering thermogenesis in newborn mammals as well as the adults (1). BAT-mediated thermogenesis is highly regulated by the sympathetic nervous system, predominantly via β adrenergic receptor (2, 3). Recent studies have shown that BAT activities in human adults are negatively correlated with body mass index (BMI) and other diabetic parameters (4-6). BAT has thus been proposed as a potential target for anti-obesity/anti-diabetes therapy focusing on modulation of energy balance (6-8). While several cold challenge-based positron emission tomography (PET) methods are established for detecting human BAT (9-13), there is essentially no standardized protocol for imaging and quantification of BAT in small animal models such as mice. Here we describe a robust PET/CT imaging method for functional assessment of BAT in mice. Briefly, adult C57BL/6J mice were cold treated under fasting conditions for a duration of 4 hours before they received one dose of (18)F-Fluorodeoxyglucose (FDG). The mice were remained in the cold for one additional hour post FDG injection, and then scanned with a small animal-dedicated micro-PET/CT system. The acquired PET images were co-registered with the CT images for anatomical references and analyzed for FDG uptake in the interscapular BAT area to present BAT activity. This standardized cold-treatment and imaging protocol has been validated through testing BAT activities during pharmacological interventions, for example, the suppressed BAT activation by the treatment of β-adrenoceptor antagonist propranolol (14, 15), or the enhanced BAT activation by β3 agonist BRL37344 (16). The method described here can be applied to screen for drugs/compounds that modulate BAT activity, or to identify genes/pathways that are involved in BAT development and regulation in various preclinical and basic studies.
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Affiliation(s)
- Xukui Wang
- Department of Translational Imaging, The Methodist Hospital Research Institute, Houston, TX, USA
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28
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Gilsanz V, Smith ML, Goodarzian F, Kim M, Wren TAL, Hu HH. Changes in brown adipose tissue in boys and girls during childhood and puberty. J Pediatr 2012; 160:604-609.e1. [PMID: 22048045 PMCID: PMC3307823 DOI: 10.1016/j.jpeds.2011.09.035] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 08/08/2011] [Accepted: 09/21/2011] [Indexed: 10/15/2022]
Abstract
OBJECTIVE To characterize the changes in brown adipose tissue (BAT) occurring during puberty in boys and girls. STUDY DESIGN We examined the prevalence and the volume of BAT at different stages of sexual development in 73 pediatric patients who underwent positron emission tomography (PET)/computed tomography (CT) studies. RESULTS Of the 73 patients studied, 43 (59%) had BAT depicted on PET/CT. The presence of BAT was detected significantly less frequently on PET/CT in prepubertal subjects (Tanner stage 1) than in pubertal subjects (Tanner stages 2-5) (15% vs 75%). BAT volume also increased during puberty, with a significantly greater magnitude of the increase in the final 2 stages of puberty (Tanner stages 4 and 5) than in earlier stages (Tanner stages 1-3) (boys: 499 ± 246 vs 50 ± 36, P < .0001; girls: 286 ± 139 vs 36 ± 29, P = .024). Changes in BAT volume were also significantly greater in boys than in girls (P = .004) and were closely related to muscle volume (r = 0.52, P < .01 for boys; r = 0.64, P < .01 for girls). CONCLUSION The presence and volume of BAT increase rapidly during puberty. Metabolic and hormonal events related to the achievement of sexual maturity are likely responsible for this increase.
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Affiliation(s)
- Vicente Gilsanz
- Department of Radiology, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA 90027, USA.
| | - Michelle L. Smith
- Department of Radiology, Childrens Hospital Los Angeles, Keck School of Medicine
| | - Fariba Goodarzian
- Department of Radiology, Childrens Hospital Los Angeles, Keck School of Medicine
,Department of Pediatrics, Childrens Hospital Los Angeles, Keck School of Medicine
| | - Mimi Kim
- Department of Pediatrics, Childrens Hospital Los Angeles, Keck School of Medicine
,Division of Endocrinology and Metabolism, Childrens Hospital Los Angeles, Keck School of Medicine
| | - Tishya A. L. Wren
- Department of Radiology, Childrens Hospital Los Angeles, Keck School of Medicine
,Department of Orthopaedic Surgery, Childrens Hospital Los Angeles, Keck School of Medicine
| | - Houchun H. Hu
- Department of Radiology, Childrens Hospital Los Angeles, Keck School of Medicine
,Department of Electrical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90027
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29
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Ouellet V, Labbé SM, Blondin DP, Phoenix S, Guérin B, Haman F, Turcotte EE, Richard D, Carpentier AC. Brown adipose tissue oxidative metabolism contributes to energy expenditure during acute cold exposure in humans. J Clin Invest 2012; 122:545-52. [PMID: 22269323 PMCID: PMC3266793 DOI: 10.1172/jci60433] [Citation(s) in RCA: 740] [Impact Index Per Article: 61.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 11/16/2011] [Indexed: 11/17/2022] Open
Abstract
Brown adipose tissue (BAT) is vital for proper thermogenesis during cold exposure in rodents, but until recently its presence in adult humans and its contribution to human metabolism were thought to be minimal or insignificant. Recent studies using PET with 18F-fluorodeoxyglucose (18FDG) have shown the presence of BAT in adult humans. However, whether BAT contributes to cold-induced nonshivering thermogenesis in humans has not been proven. Using PET with 11C-acetate, 18FDG, and 18F-fluoro-thiaheptadecanoic acid (18FTHA), a fatty acid tracer, we have quantified BAT oxidative metabolism and glucose and nonesterified fatty acid (NEFA) turnover in 6 healthy men under controlled cold exposure conditions. All subjects displayed substantial NEFA and glucose uptake upon cold exposure. Furthermore, we demonstrated cold-induced activation of oxidative metabolism in BAT, but not in adjoining skeletal muscles and subcutaneous adipose tissue. This activation was associated with an increase in total energy expenditure. We found an inverse relationship between BAT activity and shivering. We also observed an increase in BAT radio density upon cold exposure, indicating reduced BAT triglyceride content. In sum, our study provides evidence that BAT acts as a nonshivering thermogenesis effector in humans.
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Affiliation(s)
- Véronique Ouellet
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada.
Department of Medicine, Centre de recherche clinique Etienne-Le Bel, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Unité de recherche sur la nutrition et le métabolisme, Montfort Hospital, University of Ottawa, Ottawa, Ontario, Canada.
Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Sébastien M. Labbé
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada.
Department of Medicine, Centre de recherche clinique Etienne-Le Bel, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Unité de recherche sur la nutrition et le métabolisme, Montfort Hospital, University of Ottawa, Ottawa, Ontario, Canada.
Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Denis P. Blondin
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada.
Department of Medicine, Centre de recherche clinique Etienne-Le Bel, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Unité de recherche sur la nutrition et le métabolisme, Montfort Hospital, University of Ottawa, Ottawa, Ontario, Canada.
Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Serge Phoenix
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada.
Department of Medicine, Centre de recherche clinique Etienne-Le Bel, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Unité de recherche sur la nutrition et le métabolisme, Montfort Hospital, University of Ottawa, Ottawa, Ontario, Canada.
Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Brigitte Guérin
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada.
Department of Medicine, Centre de recherche clinique Etienne-Le Bel, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Unité de recherche sur la nutrition et le métabolisme, Montfort Hospital, University of Ottawa, Ottawa, Ontario, Canada.
Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - François Haman
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada.
Department of Medicine, Centre de recherche clinique Etienne-Le Bel, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Unité de recherche sur la nutrition et le métabolisme, Montfort Hospital, University of Ottawa, Ottawa, Ontario, Canada.
Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Eric E. Turcotte
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada.
Department of Medicine, Centre de recherche clinique Etienne-Le Bel, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Unité de recherche sur la nutrition et le métabolisme, Montfort Hospital, University of Ottawa, Ottawa, Ontario, Canada.
Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Denis Richard
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada.
Department of Medicine, Centre de recherche clinique Etienne-Le Bel, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Unité de recherche sur la nutrition et le métabolisme, Montfort Hospital, University of Ottawa, Ottawa, Ontario, Canada.
Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - André C. Carpentier
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada.
Department of Medicine, Centre de recherche clinique Etienne-Le Bel, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Unité de recherche sur la nutrition et le métabolisme, Montfort Hospital, University of Ottawa, Ottawa, Ontario, Canada.
Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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Pace L, Nicolai E, D'Amico D, Ibello F, Della Morte AM, Salvatore B, Pizzuti LM, Salvatore M, Soricelli A. Determinants of physiologic 18F-FDG uptake in brown adipose tissue in sequential PET/CT examinations. Mol Imaging Biol 2012; 13:1029-35. [PMID: 20852948 DOI: 10.1007/s11307-010-0431-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE The aim of this study was to assess independent predictors of 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG) uptake in brown adipose tissue (BAT) in patients undergoing repeated positron emission tomography (PET)/computed tomography (CT) scans. PROCEDURES Eight hundred forty-eight (mean age 50.9 ± 16 years) patients in whom PET/CT scan was repeated (mean interval 5 ± 1.5 months) constituted the study group. (18)F-FDG uptake in characteristic areas of BAT, with CT density of adipose tissue, greater than background soft-tissue activity was considered as evidence of BAT uptake. Both distribution and maximum standardized uptake values (SUVmax) were registered. Clinical and anamnestic data were collected for each patient. RESULTS (18)F-FDG uptake in BAT was present in 8.6% patients at first scan. Independent predictors of presence of uptake were age (younger), gender (female), body mass index (lower), and maximum outdoor temperature (lower). Age was the only independent predictor of BAT (18)F-FDG uptake distribution, while SUVmax was related to both age and outdoor temperature. Independent determinants of persistence of BAT (18)F-FDG uptake at second PET/CT were outdoor temperature at time of second scan and extension of metabolically active BAT at first scan. CONCLUSIONS Age, body mass index, and outdoor temperature are significant determinants of BAT evidence at (18)F-FDG PET/CT. Moreover, extension of BAT and outdoor temperature are the strongest determinants of persistence of BAT evidence on (18)F-FDG PET/CT in repeated scan.
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Affiliation(s)
- Leonardo Pace
- Dipartimento di Scienze Biomorfologiche e Funzionali, Facoltà di Medicina e Chirurgia, Università degli Studi di Napoli Federico II, Napoli, Italy.
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Boss O, Farmer SR. Recruitment of brown adipose tissue as a therapy for obesity-associated diseases. Front Endocrinol (Lausanne) 2012; 3:14. [PMID: 22654854 PMCID: PMC3356088 DOI: 10.3389/fendo.2012.00014] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 01/17/2012] [Indexed: 01/23/2023] Open
Abstract
Brown adipose tissue (BAT) has been recognized for more than 20 years to play a key role in cold-induced non-shivering thermogenesis (CIT, NST), and body weight homeostasis in animals. BAT is a flexible tissue that can be recruited by stimuli (including small molecules in animals), and atrophies in the absence of a stimulus. In fact, the contribution of BAT (and UCP1) to resting metabolic rate and healthy body weight homeostasis in animals (rodents) is now well established. Many investigations have shown that resistance to obesity and associated disorders in various rodent models is due to increased BAT mass and the number of brown adipocytes or UCP1 expression in various depots. The recent discovery of active BAT in adult humans has rekindled the notion that BAT is a therapeutic target for combating obesity-related metabolic disorders. In this review, we highlight investigations performed in rodents that support the contention that activation of BAT formation and/or function in obese individuals is therapeutically powerful. We also propose that enhancement of brown adipocyte functions in white adipose tissue (WAT) will also regulate energy balance as well as reduce insulin resistance in obesity-associated inflammation in WAT.
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Affiliation(s)
- Olivier Boss
- Energesis Pharmaceuticals, Inc.Cambridge, MA, USA
| | - Stephen R. Farmer
- Department of Biochemistry, Boston University School of MedicineBoston, MA, USA
- *Correspondence: Stephen R. Farmer, Department of Biochemistry, Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA. e-mail:
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Richard D, Monge-Roffarello B, Chechi K, Labbé SM, Turcotte EE. Control and physiological determinants of sympathetically mediated brown adipose tissue thermogenesis. Front Endocrinol (Lausanne) 2012; 3:36. [PMID: 22654862 PMCID: PMC3356074 DOI: 10.3389/fendo.2012.00036] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 02/13/2012] [Indexed: 02/05/2023] Open
Abstract
Brown adipose tissue (BAT) represents a remarkable heat-producing tissue. The thermogenic potential of BAT is conferred by uncoupling protein 1, a protein found uniquely in brown adipocytes. BAT activity and capacity is controlled by the sympathetic nervous system (SNS), which densely innervates brown fat depots. SNS-mediated BAT thermogenesis is essentially governed by hypothalamic and brainstem neurons. BAT activity is also modulated by brain energy balance pathways including the very significant brain melanocortin system, suggesting a genuine involvement of SNS-mediated BAT thermogenesis in energy homeostasis. The use of positron emission tomography/computed tomography scanning has revealed the presence of well-defined BAT depots in the cervical, clavicular, and paraspinal areas in adult humans. The prevalence of these depots is higher in subjects exposed to low temperature and is also higher in women compared to men. Moreover, the prevalence of BAT decreases with age and body fat mass, suggesting that BAT could be involved in energy balance regulation and obesity in humans. This short review summarizes recent progress made in our understanding of the control of SNS-mediated BAT thermogenesis and of the determinants of BAT prevalence or detection in humans.
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Affiliation(s)
- Denis Richard
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec et Groupe interdisciplinaire de Recherche sur l’Obésité de l’Université LavalQuébec, QC, Canada
- *Correspondence: Denis Richard, Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, 2725 Chemin Sainte-Foy, Québec, QC, Canada G1V 4G5. e-mail:
| | - Boris Monge-Roffarello
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec et Groupe interdisciplinaire de Recherche sur l’Obésité de l’Université LavalQuébec, QC, Canada
| | - Kanta Chechi
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec et Groupe interdisciplinaire de Recherche sur l’Obésité de l’Université LavalQuébec, QC, Canada
| | - Sébastien M. Labbé
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec et Groupe interdisciplinaire de Recherche sur l’Obésité de l’Université LavalQuébec, QC, Canada
| | - Eric E. Turcotte
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec et Groupe interdisciplinaire de Recherche sur l’Obésité de l’Université LavalQuébec, QC, Canada
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Hickeson M, Abikhzer G. Review of Physiologic and Pathophysiologic Sources of Fluorodeoxyglucose Uptake in the Chest Wall on PET. PET Clin 2011; 6:339-64. [PMID: 27156728 DOI: 10.1016/j.cpet.2011.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The chest wall can be defined as the osseous and soft tissue structures that form the outer framework of the thorax and move during breathing. Topics discussed in this article include physiologic uptake of fluorodeoxyglucose, benign diseases of the chest wall, and malignant tumors of the chest wall.
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Affiliation(s)
- Marc Hickeson
- Division of Nuclear Medicine, McGill University Health Centre, Royal Victoria Hospital, 687 Pine Avenue West, M2.11, Montreal, Quebec H3A 1A1, Canada
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Donswijk ML, Broekhuizen-de Gast HS, Torigian DA, Alavi A, Kwee TC, Lam MG. PET Assessment of Brown Fat. PET Clin 2011; 6:365-75. [DOI: 10.1016/j.cpet.2011.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Garcia C, Bandaru V, Van Nostrand D, Chennupati S, Atkins F, Acio E, Kulkarni K, Majd M. Effective reduction of brown fat FDG uptake by controlling environmental temperature prior to PET scan: an expanded case series. Mol Imaging Biol 2011; 12:652-6. [PMID: 20237858 DOI: 10.1007/s11307-010-0298-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Brown fat uptake of 2-deoxy-2-[F-18]fluoro-D: -glucose (FDG) on a positron emission tomography (PET) scan may limit the ability to assess for cancer. Previously, Garcia et al. demonstrated in ten patients a significant decrease in brown fat uptake of 2-deoxy-2-[F-18]fluoro-D: -glucose (FDG) after controlling the patient's environmental temperature. OBJECTIVE The objective of the current study is to validate the effectiveness of controlled environmental temperature (CET) to reduce physiologic brown fat (BF) FDG uptake on a PET scan in a larger series. METHOD A retrospective review was performed from January 2002 to October 2007 of patients who had (1) a pattern of FDG uptake on PET scan consistent with BF, (2) no evidence of cancer by computed tomography in the regions of interest noted below, (3) repeat scan with CET within 4 months of the 1st PET scan, and (4) no use of drugs reported to reduce BF FDG uptake (e.g., benzodiazepine, beta-blockers, reserpine) unless they were used identically prior to and during both studies. The FDG-PET and controlled environmental temperature-positron emission tomography (CET-PET) scans were performed as per protocol. The non-CET and CET-PET images were blinded/randomized, and three physicians assessed three regions (right neck, left neck, and paraspinal area) semiquantitatively using the following scale: "0" (background [bkgd]), 1 + (> bkgd < liver), 2 + (equal to liver), 3 + (> liver). Standard uptake value (SUV) data was recorded. Results were analyzed using a two-tailed t test. RESULTS Of 8,640 FDG-PET scans performed, 30 patients (four male, 26 female) met the above criteria. The median age was 36 years (range, 12-60 years). The mean (± 1 standard deviation) of differences in the scores between the two studies for right neck, left neck, and paraspinal regions, respectively, were for reader 1:(2.1 ± 1.37), (1.95 ± 1.43), and (1.85 ± 1.26); reader 2 (2.3 ± 1.40), (1.70 ± 1.13), and (1.77 ± 1.13); reader 3 (2.17 ± 1.17), (2.20 ± 1.18), and (0.50 ± 1.30); for maximum SUV score (3.4 ± 2.9), (3.3 ± 2.9), and (1.77 ± 1.13). All p values were <0.001. CONCLUSION In this larger series, CET effectively reduced the false-positive (18)FDG uptake in BF on PET scans without the use of drugs.
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Affiliation(s)
- Carlos Garcia
- Division of Nuclear Medicine, Department of Medicine, Washington Hospital Center, 110 Irving St. NW, Washington, DC 20010, USA.
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Nedergaard J, Bengtsson T, Cannon B. Three years with adult human brown adipose tissue. Ann N Y Acad Sci 2011; 1212:E20-36. [DOI: 10.1111/j.1749-6632.2010.05905.x] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Culverwell AD, Scarsbrook AF, Chowdhury FU. False-positive uptake on 2-[¹⁸F]-fluoro-2-deoxy-D-glucose (FDG) positron-emission tomography/computed tomography (PET/CT) in oncological imaging. Clin Radiol 2011; 66:366-82. [PMID: 21356398 DOI: 10.1016/j.crad.2010.12.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 12/14/2010] [Accepted: 12/21/2010] [Indexed: 01/29/2023]
Abstract
With the increasing utilization of integrated positron-emission tomography/computed tomography (PET/CT) using the glucose analogue 2-[¹⁸F]-fluoro-2-deoxy-D-glucose (FDG) in oncological imaging, it is important for radiologists and nuclear medicine physicians to be aware that FDG uptake is not specific for malignancy, as many different physiological variants and benign pathological conditions can also exhibit increased glucose metabolism. Such false-positive FDG uptake often arises outside the area of primary interest and may mimic malignant disease, thereby confounding accurate interpretation of PET/CT studies. With the use of illustrative clinical cases, this article will provide a systematic overview of potential interpretative pitfalls and illustrate how such unexpected findings can be appropriately evaluated.
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Affiliation(s)
- A D Culverwell
- Department of Clinical Radiology, Leeds Teaching Hospitals NHS Trust, UK
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Abstract
OBJECTIVE Quantification of 18-fluorodeoxyglucose (FDG) uptake in inflamed high-risk carotid atherosclerotic plaques is challenged by the spatial resolution of positron emission tomography (PET) and luminal blood activity. Late acquisition protocols have been used to overcome these challenges to enhance the contrast between the plaque and blood-pool FDG activity. However, for prospective studies the late acquisition is inconvenient for the patient and staff, and most retrospective studies of plaque uptake use data from early acquisition protocols. The objective was to evaluate changes in the quantification methods of FDG uptake in carotid artery plaques between early and late PET scans. METHODS FDG uptake 1 and 3 h after tracer injection was compared in 19 carotid artery plaques. The average plaque maximum standardized uptake value (SUVmax) and a target to background ratio (TBR), using venous blood-pool activity as background, were evaluated at the two time points. These methods have been shown earlier to quantitate the degree of inflammation in late hour scans. RESULTS A good individual plaque FDG uptake consistency was found between the two time points for SUVmax, r²=0.86. In contrast, the ratio method did not conserve the results between the two time points: TBR r²=0.34. For both methods, absolute values changed over time. TBR values generally increased as blood pool activity decreased, whereas the individual plaque SUVmax values showed both increases and decreases over time. CONCLUSION Identification of carotid plaque inflammation with PET can be performed 1 h after FDG injection using SUVmax for plaque FDG uptake quantification.
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Abstract
In initial staging of head and neck cancers, the addition of FDG PET to conventional imaging improves the accuracy for cervical nodal metastases. The sensitivity of FDG PET is, however, limited in nodes <1 cm and in completely necrotic nodes. In the posttherapy setting, PET scans obtained at least 10 weeks after radiotherapy have an excellent predictive value to rule out residual disease. Due to the limited positive predictive value of FDG PET after radiation therapy, a positive PET scan needs to be confirmed before management decisions are made.
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Affiliation(s)
- Yusuf Menda
- Division of Nuclear Medicine, Department of Radiology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
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Abstract
(18)F-fluorodeoxyglucose (FDG) is the radiotracer used in the vast majority of positron emission tomography (PET) cancer studies. FDG is a powerful radiotracer that provides valuable data in many cancer types. Normal FDG biodistribution is easily identified. In the PET-only era, physiological uptake provided important anatomical landmarks. However, the normal biodistribution of FDG is often variable and can be altered by intrinsic or iatrogenic factors. Recognizing these patterns of altered biodistribution is important for optimal FDG-PET interpretation. Altered FDG uptake in muscles, brown adipose tissue, bone marrow, the urinary tract, and the bowel is demonstrated in a significant proportion of patients, which can hide underlying malignant foci or mimic malignant lesions. The introduction of PET/computed tomography revolutionized PET imaging, bringing much-needed anatomical information. This modality allowed better characterization of some types of uptake, particularly brown adipose tissue FDG uptake. Different approaches to minimize interference from altered FDG biodistribution should be considered when performing PET scans. Otherwise, careful review and correlation of metabolic (FDG-PET) and anatomical (computed tomography) data should be performed to accurately characterize the foci of increased FDG uptake.
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Affiliation(s)
- Christian Cohade
- Department of Nuclear Medicine, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
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Liu Y, Ghesani NV, Zuckier LS. Physiology and pathophysiology of incidental findings detected on FDG-PET scintigraphy. Semin Nucl Med 2010; 40:294-315. [PMID: 20513451 DOI: 10.1053/j.semnuclmed.2010.02.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A routine feature of positron emission tomography/computed tomography (PET/CT) imaging is whole-body acquisition that results in many unexpected findings identified outside of the primary region of abnormality. Furthermore, (18)F-fluorodeoxyglucose (FDG) is a marker of glycolysis and does not specifically accumulate in malignancy. Understanding the physiology and pathophysiology of normal FDG distribution and common incidental findings is therefore essential to the physician interpreting whole-body FDG-PET/CT studies. Whereas many incidental findings are benign and of limited clinical significance, others represent uncommon manifestations of the primary malignancy, second malignancies, or various clinically significant pathologic processes. Patients with a single malignancy are at greater risk of developing synchronous or metachronous second malignancies, possibly related to exposure to shared carcinogenic agents or presence of prooncogenic mutations. The decision of how to pursue an intervention on the basis of an incidental finding is generally left to clinical judgment.
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Affiliation(s)
- Yiyan Liu
- Nuclear Medicine Section, Department of Radiology, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, NJ, USA.
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Zukotynski KA, Fahey FH, Laffin S, Davis R, Treves ST, Grant FD, Drubach LA. Seasonal variation in the effect of constant ambient temperature of 24 degrees C in reducing FDG uptake by brown adipose tissue in children. Eur J Nucl Med Mol Imaging 2010; 37:1854-60. [PMID: 20505932 DOI: 10.1007/s00259-010-1485-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Accepted: 04/18/2010] [Indexed: 11/28/2022]
Abstract
PURPOSE It has been shown that warming patients prior to and during (18)F-FDG uptake by controlling the room temperature can decrease uptake by brown adipose tissue (BAT). The aim of this study is to determine if this effect is subject to seasonal variation. METHODS A retrospective review was conducted of all patients referred for whole-body (18)F-FDG PET between December 2006 and December 2008. After December 2007, all patients were kept in the PET injection room at a constant 24 degrees C for 30 min before and until 1 h following FDG administration. Patients over 22 years of age and those who received pre-medication known to reduce FDG uptake by BAT were excluded. One hundred and three patients were warmed to 24 degrees C prior to scanning. The number of patients showing uptake by BAT in this group was compared to a control group of 99 patients who underwent PET prior to December 2007 when the injection room temperature was 21 degrees C. RESULTS Uptake by BAT occurred in 9% of studies performed after patient warming (24 degrees C), compared to 27% of studies performed on the control group (21 degrees C) (p < 0.00001). The effect of warming on decreasing FDG accumulation in BAT was statistically significant in the winter (p < 0.005) and summer (p < 0.001). However, in the spring and autumn, though the effect of warming on decreasing FDG accumulation in BAT was evident, it was not statistically significant (p > 0.05). CONCLUSION Maintaining room temperature at a constant 24 degrees C for 30 min prior to and 1 h after IV tracer administration significantly decreases FDG uptake by BAT in children. This effect is greatest in the summer and winter.
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Affiliation(s)
- Katherine A Zukotynski
- Department of Imaging, Division of Nuclear Medicine, Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Boston, MA 02115, USA.
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Paes FM, Kalkanis DG, Sideras PA, Serafini AN. FDG PET/CT of extranodal involvement in non-Hodgkin lymphoma and Hodgkin disease. Radiographics 2010; 30:269-91. [PMID: 20083598 DOI: 10.1148/rg.301095088] [Citation(s) in RCA: 198] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The term extranodal disease refers to lymphomatous infiltration of anatomic sites other than the lymph nodes. Almost any organ can be affected by lymphoma, with the most common extranodal sites of involvement being the stomach, spleen, Waldeyer ring, central nervous system, lung, bone, and skin. The prevalence of extranodal involvement in non-Hodgkin lymphoma and Hodgkin disease has increased in the past decade. The imaging characteristics of extranodal involvement can be subtle or absent at conventional computed tomography (CT). Imaging of tumor metabolism with 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) has facilitated the identification of affected extranodal sites, even when CT has demonstrated no lesions. More recently, hybrid PET/CT has become the standard imaging modality for initial staging, follow-up, and treatment response assessment in patients with lymphoma and has proved superior to CT in these settings. Certain PET/CT patterns are suggestive of extranodal disease and can help differentiate tumor from normal physiologic FDG activity, particularly in the mucosal tissues, bone marrow, and organs of the gastrointestinal tract. Familiarity with the different extranodal manifestations in various locations is critical for correct image interpretation. In addition, a knowledge of the differences in FDG avidity among the histologic subtypes of lymphoma, appropriate timing of scanning after therapeutic interventions, and use of techniques to prevent brown fat uptake are essential for providing the oncologist with accurate information.
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Affiliation(s)
- Fabio M Paes
- Department of Radiology, Division of Nuclear Medicine, Jackson Memorial Hospital, University of Miami and Miller School of Medicine, 1080 NW 19th Street, Miami, FL 33136, USA.
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Abstract
OBJECTIVE The purpose of this article is to review the physiology and describe the typical and atypical presentations of brown fat on (18)F-FDG PET. CONCLUSION The presence of brown fat on FDG PET has the potential to lead to misinterpretation and unneeded invasive tests, which can be avoided by using measures such as ensuring the patient is warm, reducing FDG uptake in brown fat before the procedure, and correlating PET uptake to a specific anatomic location with PET/CT fusion imaging.
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Saito M, Okamatsu-Ogura Y, Matsushita M, Watanabe K, Yoneshiro T, Nio-Kobayashi J, Iwanaga T, Miyagawa M, Kameya T, Nakada K, Kawai Y, Tsujisaki M. High incidence of metabolically active brown adipose tissue in healthy adult humans: effects of cold exposure and adiposity. Diabetes 2009; 58:1526-31. [PMID: 19401428 PMCID: PMC2699872 DOI: 10.2337/db09-0530] [Citation(s) in RCA: 1437] [Impact Index Per Article: 95.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE The significant roles of brown adipose tissue (BAT) in the regulation of energy expenditure and adiposity are established in small rodents but have been controversial in humans. The objective is to examine the prevalence of metabolically active BAT in healthy adult humans and to clarify the effects of cold exposure and adiposity. RESEARCH DESIGN AND METHODS In vivo 2-[(18)F]fluoro-2-deoxyglucose (FDG) uptake into adipose tissue was measured in 56 healthy volunteers (31 male and 25 female subjects) aged 23-65 years by positron emission tomography (PET) combined with X-ray computed tomography (CT). RESULTS When exposed to cold (19 degrees C) for 2 h, 17 of 32 younger subjects (aged 23-35 years) and 2 of 24 elderly subjects (aged 38-65 years) showed a substantial FDG uptake into adipose tissue of the supraclavicular and paraspinal regions, whereas they showed no detectable uptake when kept warm (27 degrees C). Histological examinations confirmed the presence of brown adipocytes in these regions. The cold-activated FDG uptake was increased in winter compared with summer (P < 0.001) and was inversely related to BMI (P < 0.001) and total (P < 0.01) and visceral (P < 0.001) fat areas estimated from CT image at the umbilical level. CONCLUSIONS Our findings, being against the conventional view, indicate the high incidence of metabolically active BAT in adult humans and suggest a role in the control of body temperature and adiposity.
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Affiliation(s)
- Masayuki Saito
- Department of Nutrition, School of Nursing and Nutrition, Tenshi College, Sapporo, Japan.
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Virtanen KA, Lidell ME, Orava J, Heglind M, Westergren R, Niemi T, Taittonen M, Laine J, Savisto NJ, Enerbäck S, Nuutila P. Functional brown adipose tissue in healthy adults. N Engl J Med 2009; 360:1518-25. [PMID: 19357407 DOI: 10.1056/nejmoa0808949] [Citation(s) in RCA: 2312] [Impact Index Per Article: 154.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Using positron-emission tomography (PET), we found that cold-induced glucose uptake was increased by a factor of 15 in paracervical and supraclavicular adipose tissue in five healthy subjects. We obtained biopsy specimens of this tissue from the first three consecutive subjects and documented messenger RNA (mRNA) and protein levels of the brown-adipocyte marker, uncoupling protein 1 (UCP1). Together with morphologic assessment, which showed numerous multilocular, intracellular lipid droplets, and with the results of biochemical analysis, these findings document the presence of substantial amounts of metabolically active brown adipose tissue in healthy adult humans.
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Hallenborg P, Feddersen S, Madsen L, Kristiansen K. The tumor suppressors pRB and p53 as regulators of adipocyte differentiation and function. Expert Opin Ther Targets 2009; 13:235-46. [DOI: 10.1517/14712590802680141] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Ukropec J, Ukropcova B, Kurdiova T, Gasperikova D, Klimes I. Adipose tissue and skeletal muscle plasticity modulates metabolic health. Arch Physiol Biochem 2008; 114:357-68. [PMID: 19016045 DOI: 10.1080/13813450802535812] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Obesity, accumulation of adipose tissue, develops when energy intake exceeds energy expenditure. Adipose tissue is essential for buffering the differences between energy intake and expenditure by accumulating lipids while skeletal muscle is the energy burning machine. Here we adopted the concept that (i) adipose tissue ability to regulate the storage capacity for lipids as well as (ii) dynamic regulation of muscle and adipose tissue secretory and metabolic activity is important for maintaining the metabolic health. This might be at least in part related to tissue plasticity, a phenomenon enabling dynamic modulation of the tissue phenotype in different physiological and pathophysiological situations. Recent advances in our understanding of the complex endocrine function of adipose tissue in regulating lipid metabolism, adipogenesis, angiogenesis, extracellular matrix remodelling, inflammation and oxidative stress prompted us to review the role of tissue plasticity--dynamic changes in adipose tissue and skeletal muscle metabolic and endocrine phenotype--in determining the difference between metabolic health and disease.
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Affiliation(s)
- Jozef Ukropec
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovak Republic.
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Zukotynski KA, Fahey FH, Laffin S, Davis R, Treves ST, Grant FD, Drubach LA. Constant ambient temperature of 24 degrees C significantly reduces FDG uptake by brown adipose tissue in children scanned during the winter. Eur J Nucl Med Mol Imaging 2008; 36:602-6. [PMID: 19037639 DOI: 10.1007/s00259-008-0983-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 10/03/2008] [Indexed: 11/25/2022]
Abstract
PURPOSE The aim of this study was to determine if warming patients prior to and during (18)F-FDG uptake by controlling the room temperature could decrease uptake by brown adipose tissue (BAT). METHODS A group of 40 children underwent (18)F-FDG PET after being kept in the injection room at a constant temperature of 24 degrees C for half an hour before and 1 hour after intravenous tracer administration. The rate of uptake by BAT in this group was compared to the uptake in a control group of 45 patients who underwent PET when the injection room temperature was 21 degrees C. RESULTS Uptake by BAT occurred in 5% of studies in the temperature-controlled room compared to 31% of studies performed when the injection room temperature was 21 degrees C (p<0.002). CONCLUSION Maintaining room temperature at a constant 24 degrees C, half an hour prior to and during the period of FDG uptake significantly decreases accumulation of FDG in BAT in children.
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Affiliation(s)
- Katherine A Zukotynski
- Department of Radiology, Division of Nuclear Medicine/PET, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
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