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Buitinga M, Veeraiah P, Haans F, Schrauwen-Hinderling VB. Ectopic lipid deposition in muscle and liver, quantified by proton magnetic resonance spectroscopy. Obesity (Silver Spring) 2023; 31:2447-2459. [PMID: 37667838 DOI: 10.1002/oby.23865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/09/2023] [Accepted: 05/09/2023] [Indexed: 09/06/2023]
Abstract
Advances in the development of noninvasive imaging techniques have spurred investigations into ectopic lipid deposition in the liver and muscle and its implications in the development of metabolic diseases such as type 2 diabetes. Computed tomography and ultrasound have been applied in the past, though magnetic resonance-based methods are currently considered the gold standard as they allow more accurate quantitative detection of ectopic lipid stores. This review focuses on methodological considerations of magnetic resonance-based methods to image hepatic and muscle fat fractions, and it emphasizes anatomical and morphological aspects and how these may influence data acquisition, analysis, and interpretation.
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Affiliation(s)
- Mijke Buitinga
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht, The Netherlands
- Department of Nutrition and Movement Sciences (NUTRIM), Maastricht University, Maastricht, The Netherlands
| | - Pandichelvam Veeraiah
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht, The Netherlands
- Scannexus (Ultra-High Field Imaging Center), Maastricht, The Netherlands
- Faculty of Health Medicine and Life Sciences (FHML), Maastricht, The Netherlands
| | - Florian Haans
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Vera B Schrauwen-Hinderling
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht, The Netherlands
- Department of Nutrition and Movement Sciences (NUTRIM), Maastricht University, Maastricht, The Netherlands
- Institute for Clinical Diabetology, German Diabetes Center and Leibniz Center for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany
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2
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Stokie JR, Abbott G, Howlett KF, Hamilton DL, Shaw CS. Intramuscular lipid utilization during exercise: a systematic review, meta-analysis, and meta-regression. J Appl Physiol (1985) 2023; 134:581-592. [PMID: 36656983 DOI: 10.1152/japplphysiol.00637.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Intramuscular lipid (IMCL) utilization during exercise was controversial as numerous studies did not observe a decline in IMCL content post-exercise when assessed in muscle biopsies using biochemical techniques. Contemporary techniques including immunofluorescence microscopy and 1H-magnetic resonance spectroscopy (1H-MRS) offer advantages over biochemical techniques. The primary aim of this systematic review, meta-analysis, and meta-regression was to examine the net degradation of IMCL in response to an acute bout of cycling exercise in humans, as assessed with different analytical approaches. A secondary aim was to explore the factors influencing IMCL degradation including feeding status, exercise variables, and participant characteristics. A total of 44 studies met the inclusion criteria using biochemical, immunofluorescence, and 1H-MRS techniques. A meta-analysis was completed using a random effects model and percentage change in IMCL content calculated from the standardized mean difference. Cycling exercise resulted in a net degradation of IMCL regardless of technique (total effect -23.7%, 95% CI = -28.7 to -18.7%) and there was no difference when comparing fasted versus fed-state exercise (P > 0.05). IMCL degradation using immunofluorescence techniques detected larger effects in type I fibers compared with whole muscle using biochemical techniques (P = 0.003) and in type I fibers compared with type II fibers (P < 0.001). Although IMCL degradation was associated with exercise duration, V̇o2max, and BMI, none of these factors independently related to the change in IMCL content. These findings provide strong evidence that the analytical approach can influence the assessment of IMCL degradation in human skeletal muscle in response to exercise.
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Affiliation(s)
- Jayden R Stokie
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Gavin Abbott
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Kirsten F Howlett
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - David L Hamilton
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Christopher S Shaw
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
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3
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Daemen S, van Polanen N, Bilet L, Phielix E, Moonen-Kornips E, Schrauwen-Hinderling VB, Schrauwen P, Hesselink MKC. Postexercise changes in myocellular lipid droplet characteristics of young lean individuals are affected by circulatory nonesterified fatty acids. Am J Physiol Endocrinol Metab 2021; 321:E453-E463. [PMID: 34396784 DOI: 10.1152/ajpendo.00654.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intramyocellular lipid (IMCL) content is an energy source during acute exercise. Nonesterified fatty acid (NEFA) levels can compete with IMCL utilization during exercise. IMCL content is stored as lipid droplets (LDs) that vary in size, number, subcellular distribution, and in coating with LD protein PLIN5. Little is known about how these factors are affected during exercise and recovery. Here, we aimed to investigate the effects of acute exercise with and without elevated NEFA levels on intramyocellular LD size and number, intracellular distribution and PLIN5 coating, using high-resolution confocal microscopy. In a crossover study, 9 healthy lean young men performed a 2-h moderate intensity cycling protocol in the fasted (high NEFA levels) and glucose-fed state (low NEFA levels). IMCL and LD parameters were measured at baseline, directly after exercise and 4 h postexercise. We found that total IMCL content was not changed directly after exercise (irrespectively of condition), but IMCL increased 4 h postexercise in the fasting condition, which was due to an increased number of LDs rather than changes in size. The effects were predominantly detected in type I muscle fibers and in LDs coated with PLIN5. Interestingly, subsarcolemmal, but not intermyofibrillar IMCL content, was decreased directly after exercise in the fasting condition and was replenished during the 4 h recovery period. In conclusion, acute exercise affects IMCL storage during exercise and recovery, particularly in type I muscle fibers, in the subsarcolemmal region and in the presence of PLIN5. Moreover, the effects of exercise on IMCL content are affected by plasma NEFA levels.NEW & NOTEWORTHY Skeletal muscle stores lipids in lipid droplets (LDs) that can vary in size, number, and location and are a source of energy during exercise. Specifically, subsarcolemmal LDs were used during exercise when fasted. Exercising in the fasted state leads to postrecovery elevation in IMCL levels due to an increase in LD number in type I muscle fibers, in subsarcolemmal region and decorated with PLIN5. These effects are blunted by glucose ingestion during exercise and recovery.
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Affiliation(s)
- Sabine Daemen
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Nynke van Polanen
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Lena Bilet
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Esther Phielix
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Esther Moonen-Kornips
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Vera B Schrauwen-Hinderling
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
- Department of Radiology, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Patrick Schrauwen
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Matthijs K C Hesselink
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
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4
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Vettori A, Paolacci S, Maltese PE, Herbst KL, Cestari M, Michelini S, Michelini S, Samaja M, Bertelli M. Genetic Determinants of the Effects of Training on Muscle and Adipose Tissue Homeostasis in Obesity Associated with Lymphedema. Lymphat Res Biol 2020; 19:322-333. [PMID: 33373545 DOI: 10.1089/lrb.2020.0057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
It is widely accepted that metabolic changes associated with training are influenced by a person's genetic background. In this review, we explore the polymorphisms underlying interindividual variability in response to training of weight loss and muscle mass increase in obese individuals, with or without lymphedema, and in normal-weight subjects. We searched PubMed for articles in English published up to May 2019 using the following keywords: (((physical training[Title/Abstract] OR sport activity[Title/Abstract]) AND predisposition[Title/Abstract]) AND polymorphism [Title/Abstract]). We identified 38 single-nucleotide polymorphisms that may modulate the genetic adaptive response to training. The identification of genetic marker(s) that improve the beneficial effects of training may in perspective make it possible to assess training programs, which in combination with dietary intervention can optimize body weight reduction in obese subjects, with or without lymphedema. This is particularly important for patients with lymphedema because obesity can worsen the clinical status, and therefore, a personalized approach that could reduce obesity would be fundamental in the clinical management of lymphedema.
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Affiliation(s)
- Andrea Vettori
- Department of Biotechnology, University of Verona, Verona, Italy
| | | | | | - Karen L Herbst
- Department of Medicine, University of Arizona, Tucson, Arizona, USA.,Department of Pharmacy, University of Arizona, Tucson, Arizona, USA.,Department of Medical Imaging, University of Arizona, Tucson, Arizona, USA.,Department of Surgery, University of Arizona, Tucson, Arizona, USA
| | - Marina Cestari
- Study Centre Pianeta Linfedema, Terni, Italy.,Lymphology Sector of the Rehabilitation Service, USLUmbria2, Terni, Italy
| | - Sandro Michelini
- Department of Vascular Rehabilitation, San Giovanni Battista Hospital, Rome, Italy
| | - Serena Michelini
- Unit of Physical Medicine and Rehabilitation, Sant'Andrea Hospital, "Sapienza" University of Rome, Rome, Italy
| | - Michele Samaja
- Department of Health Science, University of Milan-San Paolo Hospital, Milan, Italy
| | - Matteo Bertelli
- MAGI'S Lab, Rovereto, Italy.,MAGI Euregio, Bolzano, Italy.,EBTNA-LAB, Rovereto, Italy
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5
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Alhulail AA, Patterson DA, Xia P, Zhou X, Lin C, Thomas MA, Dydak U, Emir UE. Fat-water separation by fast metabolite cycling magnetic resonance spectroscopic imaging at 3 T: A method to generate separate quantitative distribution maps of musculoskeletal lipid components. Magn Reson Med 2020; 84:1126-1139. [PMID: 32103549 DOI: 10.1002/mrm.28228] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 01/03/2020] [Accepted: 02/03/2020] [Indexed: 12/29/2022]
Abstract
PURPOSE To provide a rapid, noninvasive fat-water separation technique that allows producing quantitative maps of particular lipid components. METHODS The calf muscles in 5 healthy adolescents (age 12-16 years; body mass index = 20 ± 3 kg/m2 ) were scanned by two different fat fraction measurement methods. A density-weighted concentric-ring trajectory metabolite-cycling MRSI technique was implemented to collect data with a nominal resolution of 0.25 mL within 3 minutes and 16 seconds. For comparative purposes, the standard Dixon technique was performed. The two techniques were compared using structural similarity analysis. Additionally, the difference in the distribution of each lipid over the adolescent calf muscles was assessed based on the MRSI data. RESULTS The proposed MRSI technique provided individual fat fraction maps for eight musculoskeletal lipid components identified by LCModel analysis (IMC/L [CH3 ], EMCL [CH3 ], IMC/L [CH2 ]n , EMC/L [CH2 ]n , IMC/L [CH2 -CH], EMC/L [CH2 -CH], IMC/L [-CH=CH-], and EMC/L [-CH=CH-]) with mean structural similarity indices of 0.19, 0.04, 0.03, 0.50, 0.45, 0.04, 0.07, and 0.12, respectively, compared with the maps generated by the used Dixon method. Further analysis of voxels with zero structural similarity demonstrated an increased sensitivity of fat fraction lipid maps from the data acquired using this MRSI technique over the standard Dixon technique. The lipid spatial distribution over calf muscles was consistent with previously published findings in adults. CONCLUSION This MRSI technique can be a useful tool when individual lipid fat fraction maps are desired within a clinically acceptable time and with a nominal spatial resolution of 0.25 mL.
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Affiliation(s)
- Ahmad A Alhulail
- School of Health Sciences, Purdue University, West Lafayette, Indiana.,Department of Radiology and Medical Imaging, Prince Sattam bin Abdulaziz University, Al Kharj, Saudi Arabia
| | - Debra A Patterson
- School of Health Sciences, Purdue University, West Lafayette, Indiana.,Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana
| | - Pingyu Xia
- School of Health Sciences, Purdue University, West Lafayette, Indiana
| | - Xiaopeng Zhou
- School of Health Sciences, Purdue University, West Lafayette, Indiana
| | - Chen Lin
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana
| | - M Albert Thomas
- Department of Radiology, University of California Los Angeles, Los Angeles, California
| | - Ulrike Dydak
- School of Health Sciences, Purdue University, West Lafayette, Indiana.,Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana
| | - Uzay E Emir
- School of Health Sciences, Purdue University, West Lafayette, Indiana.,Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
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6
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Gadermayr M, Li K, Müller M, Truhn D, Krämer N, Merhof D, Gess B. Domain-specific data augmentation for segmenting MR images of fatty infiltrated human thighs with neural networks. J Magn Reson Imaging 2019; 49:1676-1683. [PMID: 30623506 DOI: 10.1002/jmri.26544] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/01/2018] [Accepted: 10/02/2018] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Fat-fraction has been established as a relevant marker for the assessment and diagnosis of neuromuscular diseases. For computing this metric, segmentation of muscle tissue in MR images is a first crucial step. PURPOSE To tackle the high degree of variability in combination with the high annotation effort for training supervised segmentation models (such as fully convolutional neural networks). STUDY TYPE Prospective. SUBJECTS In all, 41 patients consisting of 20 patients showing fatty infiltration and 21 healthy subjects. Field Strength/Sequence: The T1 -weighted MR-pulse sequences were acquired on a 1.5T scanner. ASSESSMENT To increase performance with limited training data, we propose a domain-specific technique for simulating fatty infiltrations (i.e., texture augmentation) in nonaffected subjects' MR images in combination with shape augmentation. For simulating the fatty infiltrations, we make use of an architecture comprising several competing networks (generative adversarial networks) that facilitate a realistic artificial conversion between healthy and infiltrated MR images. Finally, we assess the segmentation accuracy (Dice similarity coefficient). STATISTICAL TESTS A Wilcoxon signed rank test was performed to assess whether differences in segmentation accuracy are significant. RESULTS The mean Dice similarity coefficients significantly increase from 0.84-0.88 (P < 0.01) using data augmentation if training is performed with mixed data and from 0.59-0.87 (P < 0.001) if training is conducted with healthy subjects only. DATA CONCLUSION Domain-specific data adaptation is highly suitable for facilitating neural network-based segmentation of thighs with feasible manual effort for creating training data. The results even suggest an approach completely bypassing manual annotations. LEVEL OF EVIDENCE 4 Technical Efficacy: Stage 3.
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Affiliation(s)
- Michael Gadermayr
- Institute of Imaging & Computer Vision, RWTH Aachen University, Aachen, Germany.,Salzburg University of Applied Sciences, Salzburg, Austria
| | - Kexin Li
- Institute of Imaging & Computer Vision, RWTH Aachen University, Aachen, Germany
| | - Madlaine Müller
- Department of Neurology, RWTH University Hospital Aachen, Aachen, Germany
| | - Daniel Truhn
- Department of Radiology, RWTH University Hospital Aachen, Aachen, Germany
| | - Nils Krämer
- Department of Radiology, RWTH University Hospital Aachen, Aachen, Germany
| | - Dorit Merhof
- Institute of Imaging & Computer Vision, RWTH Aachen University, Aachen, Germany
| | - Burkhard Gess
- Department of Neurology, RWTH University Hospital Aachen, Aachen, Germany
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7
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Loher H, Jenni S, Bucher J, Krüsi M, Kreis R, Boesch C, Christ E. Impaired repletion of intramyocellular lipids in patients with growth hormone deficiency after a bout of aerobic exercise. Growth Horm IGF Res 2018; 42-43:32-39. [PMID: 30153529 DOI: 10.1016/j.ghir.2018.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/04/2018] [Accepted: 08/12/2018] [Indexed: 01/04/2023]
Abstract
BACKGROUND Ectopic lipids such as intramyocellular lipids (IMCL) are depleted by exercise and repleted by diet, whereas intrahepatocellular lipids (IHCL) are increased immediately after exercise. So far, it is unclear how ectopic lipids behave 24 h after exercise and whether the lack of growth hormone (GH) significantly affects ectopic lipids 24 h after exercise. METHODS Seven male patients with growth hormone deficiency (GHD) and seven sedentary male control subjects (CS) were included. VO2max was assessed by spiroergometry; visceral and subcutaneous fat by whole body MRI. 1H-MR-spectroscopy was performed in M. vastus intermedius and in the liver before and after 2 h of exercise at 50% VO2max and 24 h thereafter, while diet and physical activity were standardized. RESULTS Sedentary male subjects (7 GHD, 7 CS) were recruited. Age, BMI, waist circumference, visceral and subcutaneous fat mass was not significantly different between GHD and CS. VO2max was significantly lower in GHD vs. CS. IMCL were diminished through aerobic exercise in both groups: (-11.5 ± 21.9% in CS; -8.9% ±19.1% in GHD) and restored after 24 h in CS (-5.5 ± 26.6% compared to baseline) but not in GHD (-17.9 ± 15.3%). IHCL increased immediately after exercise and decreased to baseline within 24 h. CONCLUSION These findings suggest that GHD may affect repletion of IMCL 24 h after aerobic exercise.
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Affiliation(s)
- Hannah Loher
- Division of Diabetology, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital, University of Bern, Switzerland; Department of Medicine, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Stefan Jenni
- Division of Diabetology, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital, University of Bern, Switzerland; EndoDia Praxis, Biel, Switzerland
| | - Julie Bucher
- Division of Diabetology, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital, University of Bern, Switzerland; EndoDia Praxis, Biel, Switzerland
| | - Marion Krüsi
- Division of Diabetology, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Roland Kreis
- Department of Biomedical Research & Institute of Interventional, Diagnostic and Pediatric Radiology, University of Bern, Bern, Switzerland
| | - Chris Boesch
- Department of Biomedical Research & Institute of Interventional, Diagnostic and Pediatric Radiology, University of Bern, Bern, Switzerland
| | - Emanuel Christ
- Division of Diabetology, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital, University of Bern, Switzerland; Division of Endocrinology, Diabetology and Metabolism, University Hospital of Basel, Basel, Switzerland.
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8
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Daemen S, van Polanen N, Hesselink MKC. The effect of diet and exercise on lipid droplet dynamics in human muscle tissue. ACTA ACUST UNITED AC 2018. [PMID: 29514886 DOI: 10.1242/jeb.167015] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The majority of fat in the human body is stored as triacylglycerols in white adipose tissue. In the obese state, adipose tissue mass expands and excess lipids are stored in non-adipose tissues, such as skeletal muscle. Lipids are stored in skeletal muscle in the form of small lipid droplets. Although originally viewed as dull organelles that simply store lipids as a consequence of lipid overflow from adipose tissue, lipid droplets are now recognized as key components in the cell that exert a variety of relevant functions in multiple tissues (including muscle). Here, we review the effect of diet and exercise interventions on myocellular lipid droplets and their putative role in insulin sensitivity from a human perspective. We also provide an overview of lipid droplet biology and identify gaps for future research.
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Affiliation(s)
- Sabine Daemen
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD Maastricht, The Netherlands
| | - Nynke van Polanen
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD Maastricht, The Netherlands
| | - Matthijs K C Hesselink
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD Maastricht, The Netherlands
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9
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The Flexibility of Ectopic Lipids. Int J Mol Sci 2016; 17:ijms17091554. [PMID: 27649157 PMCID: PMC5037826 DOI: 10.3390/ijms17091554] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Revised: 08/30/2016] [Accepted: 09/01/2016] [Indexed: 02/07/2023] Open
Abstract
In addition to the subcutaneous and the visceral fat tissue, lipids can also be stored in non-adipose tissue such as in hepatocytes (intrahepatocellular lipids; IHCL), skeletal (intramyocellular lipids; IMCL) or cardiac muscle cells (intracardiomyocellular lipids; ICCL). Ectopic lipids are flexible fuel stores that can be depleted by physical exercise and repleted by diet. They are related to obesity and insulin resistance. Quantification of IMCL was initially performed invasively, using muscle biopsies with biochemical and/or histological analysis. 1H-magnetic resonance spectroscopy (1H-MRS) is now a validated method that allows for not only quantifying IMCL non-invasively and repeatedly, but also assessing IHCL and ICCL. This review summarizes the current available knowledge on the flexibility of ectopic lipids. The available evidence suggests a complex interplay between quantitative and qualitative diet, fat availability (fat mass), insulin action, and physical exercise, all important factors that influence the flexibility of ectopic lipids. Furthermore, the time frame of the intervention on these parameters (short-term vs. long-term) appears to be critical. Consequently, standardization of physical activity and diet are critical when assessing ectopic lipids in predefined clinical situations.
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10
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Janssen BH, Lassche S, Hopman MT, Wevers RA, van Engelen BGM, Heerschap A. Monitoring creatine and phosphocreatine by (13)C MR spectroscopic imaging during and after (13)C4 creatine loading: a feasibility study. Amino Acids 2016; 48:1857-66. [PMID: 27401085 PMCID: PMC4974291 DOI: 10.1007/s00726-016-2294-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 07/01/2016] [Indexed: 12/28/2022]
Abstract
Creatine (Cr) supplementation to enhance muscle performance shows variable responses among individuals and different muscles. Direct monitoring of the supplied Cr in muscles would address these differences. In this feasibility study, we introduce in vivo 3D 13C MR spectroscopic imaging (MRSI) of the leg with oral ingestion of 13C4–creatine to observe simultaneously Cr and phosphocreatine (PCr) for assessing Cr uptake, turnover, and the ratio PCr over total Cr (TCr) in individual muscles. 13C MRSI was performed of five muscles in the posterior thigh in seven subjects (two males and two females of ~20 years, one 82-year-old male, and two neuromuscular patients) with a 1H/13C coil in a 3T MR system before, during and after intake of 15 % 13C4-enriched Cr. Subjects ingested 20 g Cr/day for 4 days in four 5 g doses at equal time intervals. The PCr/TCr did not vary significantly during supplementation and was similar for all subjects and investigated muscles (average 0.71 ± 0.07), except for the adductor magnus (0.64 ± 0.03). The average Cr turnover rate, assessed in male muscles, was 2.1 ± 0.7 %/day. The linear uptake rates of Cr were variable between muscles, although not significantly different. This assessment was possible in all investigated muscles of young male volunteers, but less so in muscles of the other subjects due to lower signal-to-noise ratio. Improvements for future studies are discussed. In vivo 13C MRSI after 13C–Cr ingestion is demonstrated for longitudinal studies of Cr uptake, turnover, and PCr/TCr ratios of individual muscles in one exam.
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Affiliation(s)
- Barbara H Janssen
- Department of Radiology, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Saskia Lassche
- Department of Neurology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maria T Hopman
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ron A Wevers
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Arend Heerschap
- Department of Radiology, Radboud University Medical Center, Nijmegen, The Netherlands
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11
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Popadic Gacesa J, Schick F, Machann J, Grujic N. Intramyocellular lipids and their dynamics assessed by 1 H magnetic resonance spectroscopy. Clin Physiol Funct Imaging 2016; 37:558-566. [PMID: 26865009 DOI: 10.1111/cpf.12346] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 12/26/2015] [Indexed: 12/15/2022]
Abstract
This report provides an overview on the present knowledge on intramyocellular lipids (IMCL) and their dynamics in the course of interventions with physical activity of variable type and intensity in different population groups, as accessible by examinations using non-invasive volume-selective 1 H magnetic resonance spectroscopy (1 H MRS). IMCL serve as energy source in skeletal muscle for fat oxidation in the mitochondria and became intensively studied after discovery of their relation with insulin sensitivity. While baseline levels of IMCL concentration have been shown to be mainly dependent on the metabolic status (insulin sensitivity), on the level of training and on fibre composition in the muscles, studies applying different physical activity protocols revealed the dynamic of their depletion and replenishment. From the findings in human studies, it can be concluded that IMCL levels are potentially useful markers for monitoring metabolic adaptation of skeletal muscle to sportive activities and training.
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Affiliation(s)
- J Popadic Gacesa
- Laboratory for Functional Diagnostics, Department of Physiology, Medical School, University of Novi Sad, Novi Sad, Serbia
| | - F Schick
- Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen, Germany
| | - J Machann
- Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany.,German Center for Diabetes Research (DZD), Tübingen, Germany
| | - N Grujic
- Laboratory for Functional Diagnostics, Department of Physiology, Medical School, University of Novi Sad, Novi Sad, Serbia
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12
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Kakehi S, Tamura Y, Takeno K, Sakurai Y, Kawaguchi M, Watanabe T, Funayama T, Sato F, Ikeda SI, Kanazawa A, Fujitani Y, Kawamori R, Watada H. Increased intramyocellular lipid/impaired insulin sensitivity is associated with altered lipid metabolic genes in muscle of high responders to a high-fat diet. Am J Physiol Endocrinol Metab 2016; 310:E32-40. [PMID: 26487001 DOI: 10.1152/ajpendo.00220.2015] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 10/16/2015] [Indexed: 01/07/2023]
Abstract
The accumulation of intramyocellular lipid (IMCL) is recognized as an important determinant of insulin resistance, and is increased by a high-fat diet (HFD). However, the effects of HFD on IMCL and insulin sensitivity are highly variable. The aim of this study was to identify the genes in muscle that are related to this inter-individual variation. Fifty healthy men were recruited for this study. Before and after HFD for 3 days, IMCL levels in the tibialis anterior were measured by (1)H magnetic resonance spectroscopy, and peripheral insulin sensitivity was evaluated by glucose infusion rate (GIR) during the euglycemic-hyperinsulinemic clamp. Subjects who showed a large increase in IMCL and a large decrease in GIR by HFD were classified as high responders (HRs), and subjects who showed a small increase in IMCL and a small decrease in GIR were classified as low responders (LRs). In five subjects from each group, the gene expression profile of the vastus lateralis muscle was analyzed by DNA microarray analysis. Before HFD, gene expression profiles related to lipid metabolism were comparable between the two groups. Gene Set Enrichment Analysis demonstrated that five gene sets related to lipid metabolism were upregulated by HFD in the HR group but not in the LR group. Changes in gene expression patterns were confirmed by qRT-PCR using more samples (LR, n = 9; HR, n = 11). These results suggest that IMCL accumulation/impaired insulin sensitivity after HFD is closely associated with changes in the expression of genes related to lipid metabolism in muscle.
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Affiliation(s)
- Saori Kakehi
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan; Sportology Center, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yoshifumi Tamura
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan; Sportology Center, Juntendo University Graduate School of Medicine, Tokyo, Japan;
| | - Kageumi Takeno
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yuko Sakurai
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Minako Kawaguchi
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Takahiro Watanabe
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Takashi Funayama
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Fumihiko Sato
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Shin-Ichi Ikeda
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan; Sportology Center, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Akio Kanazawa
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yoshio Fujitani
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Ryuzo Kawamori
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan; Sportology Center, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Hirotaka Watada
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan; Sportology Center, Juntendo University Graduate School of Medicine, Tokyo, Japan; Center for Therapeutic Innovations in Diabetes, Juntendo University Graduate School of Medicine, Tokyo, Japan; and Center for Molecular Diabetology, Juntendo University Graduate School of Medicine, Tokyo, Japan
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Valaparla SK, Gao F, Daniele G, Abdul-Ghani M, Clarke GD. Fiber orientation measurements by diffusion tensor imaging improve hydrogen-1 magnetic resonance spectroscopy of intramyocellular lipids in human leg muscles. J Med Imaging (Bellingham) 2015; 2:026002. [PMID: 26158115 DOI: 10.1117/1.jmi.2.2.026002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 05/06/2015] [Indexed: 01/15/2023] Open
Abstract
Twelve healthy subjects underwent hydrogen-1 magnetic resonance spectroscopy ([Formula: see text]) acquisition ([Formula: see text]), diffusion tensor imaging (DTI) with a [Formula: see text]-value of [Formula: see text], and fat-water magnetic resonance imaging (MRI) using the Dixon method. Subject-specific muscle fiber orientation, derived from DTI, was used to estimate the lipid proton spectral chemical shift. Pennation angles were measured as 23.78 deg in vastus lateralis (VL), 17.06 deg in soleus (SO), and 8.49 deg in tibialis anterior (TA) resulting in a chemical shift between extramyocellular lipids (EMCL) and intramyocellular lipids (IMCL) of 0.15, 0.17, and 0.19 ppm, respectively. IMCL concentrations were [Formula: see text], [Formula: see text], and [Formula: see text] in SO, VL, and TA, respectively. Significant differences were observed in IMCL and EMCL pairwise comparisons in SO, VL, and TA ([Formula: see text]). Strong correlations were observed between total fat fractions from [Formula: see text] and Dixon MRI for VL ([Formula: see text]), SO ([Formula: see text]), and TA ([Formula: see text]). Bland-Altman analysis between fat fractions (FFMRS and FFMRI) showed good agreement with small limits of agreement (LoA): [Formula: see text] (LoA: [Formula: see text] to 0.69%) in VL, [Formula: see text] (LoA: [Formula: see text] to 1.33%) in SO, and [Formula: see text] (LoA: [Formula: see text] to 0.47%) in TA. The results of this study demonstrate the variation in muscle fiber orientation and lipid concentrations in these three skeletal muscle types.
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Affiliation(s)
- Sunil K Valaparla
- University of Texas Health Science Center , Research Imaging Institute, 7703 Floyd Curl Drive, San Antonio, Texas 78229-3900, United States ; University of Texas Health Science Center , Department of Radiology, 7703 Floyd Curl Drive, San Antonio, Texas 78229-3900, United States
| | - Feng Gao
- University of Texas Health Science Center , Research Imaging Institute, 7703 Floyd Curl Drive, San Antonio, Texas 78229-3900, United States
| | - Giuseppe Daniele
- University of Texas Health Science Center , Department of Medicine, Diabetes Division, 7703 Floyd Curl Drive, San Antonio, Texas 78229-3900, United States ; University of Pisa , Department of Endocrinology, Via Paradisa 2, Pisa 56124, Italy
| | - Muhammad Abdul-Ghani
- University of Texas Health Science Center , Department of Medicine, Diabetes Division, 7703 Floyd Curl Drive, San Antonio, Texas 78229-3900, United States
| | - Geoffrey D Clarke
- University of Texas Health Science Center , Research Imaging Institute, 7703 Floyd Curl Drive, San Antonio, Texas 78229-3900, United States ; University of Texas Health Science Center , Department of Radiology, 7703 Floyd Curl Drive, San Antonio, Texas 78229-3900, United States
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14
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Ogasawara J, Izawa T, Sakurai T, Sakurai T, Shirato K, Ishibashi Y, Ishida H, Ohno H, Kizaki T. The Molecular Mechanism Underlying Continuous Exercise Training-Induced Adaptive Changes of Lipolysis in White Adipose Cells. J Obes 2015; 2015:473430. [PMID: 26075089 PMCID: PMC4444571 DOI: 10.1155/2015/473430] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 04/04/2015] [Accepted: 04/27/2015] [Indexed: 01/04/2023] Open
Abstract
Physical exercise accelerates the mobilization of free fatty acids from white adipocytes to provide fuel for energy. This happens in several tissues and helps to regulate a whole-body state of metabolism. Under these conditions, the hydrolysis of triacylglycerol (TG) that is found in white adipocytes is known to be augmented via the activation of these lipolytic events, which is referred to as the "lipolytic cascade." Indeed, evidence has shown that the lipolytic responses in white adipocytes are upregulated by continuous exercise training (ET) through the adaptive changes in molecules that constitute the lipolytic cascade. During the past few decades, many lipolysis-related molecules have been identified. Of note, the discovery of a new lipase, known as adipose triglyceride lipase, has redefined the existing concepts of the hormone-sensitive lipase-dependent hydrolysis of TG in white adipocytes. This review outlines the alterations in the lipolytic molecules of white adipocytes that result from ET, which includes the molecular regulation of TG lipases through the lipolytic cascade.
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Affiliation(s)
- Junetsu Ogasawara
- Department of Molecular Predictive Medicine and Sport Science, Kyorin University, School of Medicine, Mitaka, Tokyo 181-8611, Japan
- *Junetsu Ogasawara:
| | - Tetsuya Izawa
- Graduate School of Health and Sports Science, Doshisha University, Kyotanabe, Kyoto 610-0394, Japan
| | - Tomonobu Sakurai
- Faculty of Culture and Sport Policy, Toin University of Yokohama, Yokohama, Kanagawa 225-8503, Japan
| | - Takuya Sakurai
- Department of Molecular Predictive Medicine and Sport Science, Kyorin University, School of Medicine, Mitaka, Tokyo 181-8611, Japan
| | - Ken Shirato
- Department of Molecular Predictive Medicine and Sport Science, Kyorin University, School of Medicine, Mitaka, Tokyo 181-8611, Japan
| | - Yoshinaga Ishibashi
- Department of Molecular Predictive Medicine and Sport Science, Kyorin University, School of Medicine, Mitaka, Tokyo 181-8611, Japan
| | - Hitoshi Ishida
- Department of Third Internal Medicine, Kyorin University, School of Medicine, Mitaka, Tokyo 181-8611, Japan
| | - Hideki Ohno
- Department of Molecular Predictive Medicine and Sport Science, Kyorin University, School of Medicine, Mitaka, Tokyo 181-8611, Japan
| | - Takako Kizaki
- Department of Molecular Predictive Medicine and Sport Science, Kyorin University, School of Medicine, Mitaka, Tokyo 181-8611, Japan
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15
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Bosma M. Lipid homeostasis in exercise. Drug Discov Today 2014; 19:1019-23. [PMID: 24632001 DOI: 10.1016/j.drudis.2014.03.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 03/06/2014] [Indexed: 01/08/2023]
Abstract
Fatty acids (FA) are essential energy substrates during endurance exercise. In addition to systemic supply, intramyocellular neutral lipids form an important source of FA for the working muscle. Endurance exercise training is associated with an increased reliance on lipids as a fuel source, has systemic lipid-lowering effects and results in a remodeling of skeletal muscle lipid metabolism toward increased oxidation, neutral lipid storage and turnover. Interestingly, recent studies have indicated common exercise-induced regulatory pathways for genes involved in skeletal muscle mitochondrial oxidative metabolism and lipid droplet (LD) dynamics. In this review, I discuss lipid homeostasis during acute exercise and adaptations in lipid metabolism upon exercise training in the light of recent advances in the field.
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Affiliation(s)
- Madeleen Bosma
- Department of Cell and Molecular Biology, Karolinska Institutet, PO Box 285, SE-171 77 Stockholm, Sweden.
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16
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Weis J, Bruvold M, Ortiz-Nieto F, Ahlström H. High-resolution echo-planar spectroscopic imaging of the human calf. PLoS One 2014; 9:e87533. [PMID: 24498129 PMCID: PMC3907517 DOI: 10.1371/journal.pone.0087533] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 12/27/2013] [Indexed: 11/21/2022] Open
Abstract
Background This study exploits the speed benefits of echo-planar spectroscopic imaging (EPSI) to acquire lipid spectra of skeletal muscle. The main purpose was to develop a high-resolution EPSI technique for clinical MR scanner, to visualise the bulk magnetic susceptibility (BMS) shifts of extra-myocellular lipid (EMCL) spectral lines, and to investigate the feasibility of this method for the assessment of intra-myocellular (IMCL) lipids. Methods The study group consisted of six healthy volunteers. A two dimensional EPSI sequence with point-resolved spectroscopy (PRESS) spatial localization was implemented on a 3T clinical MR scanner. Measurements were performed by means of 64×64 spatial matrix and nominal voxel size 3×3×15 mm3. The total net measurement time was 3 min 12 sec for non-water-suppressed (1 acquisition) and 12 min 48 sec for water-suppressed scans (4 acquisitions). Results Spectra of the human calf had a very good signal-to-noise ratio and linewidths sufficient to differentiate IMCL resonances from EMCL. The use of a large spatial matrix reduces inter-voxel signal contamination of the strong EMCL signals. Small voxels enabled visualisation of the methylene EMCL spectral line splitting and their BMS shifts up to 0.5 ppm relative to the correspondent IMCL line. The mean soleus muscle IMCL content of our six volunteers was 0.30±0.10 vol% (range 0.18–0.46) or 3.6±1.2 mmol/kg wet weight (range: 2.1–5.4). Conclusion This study demonstrates that high-spatial resolution PRESS EPSI of the muscle lipids is feasible on standard clinical scanners.
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Affiliation(s)
- Jan Weis
- Department of Radiology, Uppsala University Hospital, Uppsala, Sweden
- * E-mail:
| | | | | | - Håkan Ahlström
- Department of Radiology, Uppsala University Hospital, Uppsala, Sweden
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17
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Harry H, Kan HE. Quantitative proton MR techniques for measuring fat. NMR IN BIOMEDICINE 2013; 26:1609-29. [PMID: 24123229 PMCID: PMC4001818 DOI: 10.1002/nbm.3025] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 07/13/2013] [Accepted: 08/19/2013] [Indexed: 05/09/2023]
Abstract
Accurate, precise and reliable techniques for the quantification of body and organ fat distributions are important tools in physiology research. They are critically needed in studies of obesity and diseases involving excess fat accumulation. Proton MR methods address this need by providing an array of relaxometry-based (T1, T2) and chemical shift-based approaches. These techniques can generate informative visualizations of regional and whole-body fat distributions, yield measurements of fat volumes within specific body depots and quantify fat accumulation in abdominal organs and muscles. MR methods are commonly used to investigate the role of fat in nutrition and metabolism, to measure the efficacy of short- and long-term dietary and exercise interventions, to study the implications of fat in organ steatosis and muscular dystrophies and to elucidate pathophysiological mechanisms in the context of obesity and its comorbidities. The purpose of this review is to provide a summary of mainstream MR strategies for fat quantification. The article succinctly describes the principles that differentiate water and fat proton signals, summarizes the advantages and limitations of various techniques and offers a few illustrative examples. The article also highlights recent efforts in the MR of brown adipose tissue and concludes by briefly discussing some future research directions.
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Affiliation(s)
- Houchun Harry
- Corresponding Author Houchun Harry Hu, PhD Children's Hospital Los Angeles University of Southern California 4650 Sunset Boulevard Department of Radiology, MS #81 Los Angeles, California, USA. 90027 , Office: +1 (323) 361-2688 Fax: +1 (323) 361-1510
| | - Hermien E. Kan
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
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