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OBJECTIVE: There is no consensus regarding the terminology, definition, classification, diagnostic criteria, and algorithm, or reporting standards for the disease of infective native aortic aneurysm (INAA), previously known as mycotic aneurysm. The aim of this study was to establish this by performing a consensus study. METHODS: The Delphi methodology was used. Thirty-seven international experts were invited via mail to participate. Four two week Delphi rounds were performed, using an online questionnaire, initially with 22 statements and nine reporting items. The panellists rated the statements on a five point Likert scale. Comments on statements were analysed, statements revised, and results presented in iterative rounds. Consensus was defined as ≥ 75% of the panel selecting "strongly agree" or "agree" on the Likert scale, and consensus on the final assessment was defined as Cronbach's alpha coefficient > .80. RESULTS: All 38 panellists completed all four rounds, resulting in 100% participation and agreement that this study was necessary, and the term INAA was agreed to be optimal. Three more statements were added based on the results and comments of the panel, resulting in a final 25 statements and nine reporting items. All 25 statements reached an agreement of ≥ 87%, and all nine reporting items reached an agreement of 100%. The Cronbach's alpha increased for each consecutive round (round 1 = .84, round 2 = .87, round 3 = .90, and round 4 = .92). Thus, consensus was reached for all statements and reporting items. CONCLUSION: This Delphi study established the first consensus document on INAA regarding terminology, definition, classification, diagnostic criteria, and algorithm, as well as reporting standards. The results of this study create essential conditions for scientific research on this disease. The presented consensus will need future amendments in accordance with newly acquired knowledge.
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Most in vivo 31P MR studies are realized on 3T MR systems that provide sufficient signal intensity for prominent phosphorus metabolites. The identification of these metabolites in the in vivo spectra is performed by comparing their chemical shifts with the chemical shifts measured in vitro on high-field NMR spectrometers. To approach in vivo conditions at 3T, a set of phantoms with defined metabolite solutions were measured in a 3T whole-body MR system at 7.0 and 7.5 pH, at 37 °C. A free induction decay (FID) sequence with and without 1H decoupling was used. Chemical shifts were obtained of phosphoenolpyruvate (PEP), phosphatidylcholine (PtdC), phosphocholine (PC), phosphoethanolamine (PE), glycerophosphocholine (GPC), glycerophosphoetanolamine (GPE), uridine diphosphoglucose (UDPG), glucose-6-phosphate (G6P), glucose-1-phosphate (G1P), 2,3-diphosphoglycerate (2,3-DPG), nicotinamide adenine dinucleotide (NADH and NAD+), phosphocreatine (PCr), adenosine triphosphate (ATP), adenosine diphosphate (ADP), and inorganic phosphate (Pi). The measured chemical shifts were used to construct a basis set of 31P MR spectra for the evaluation of 31P in vivo spectra of muscle and the liver using LCModel software (linear combination model). Prior knowledge was successfully employed in the analysis of previously acquired in vivo data.
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Fígado/metabolismo , Músculo Esquelético/metabolismo , Ressonância Magnética Nuclear Biomolecular , Fósforo/metabolismo , Software , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Humanos , Fosfatos/metabolismo , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/metabolismo , Projetos PilotoRESUMO
An unknown intense signal (Pun ) with a mean chemical shift of 5.3 ppm was observed in 31 P MR spectra from the calf muscles of patients with the diabetic foot syndrome. The aim of the study was to identify the origin of this signal and its potential as a biomarker of muscle injury. Calf muscles of 68 diabetic patients (66.3 ± 8.6 years; body mass index = 28.2 ± 4.3 kg/m2 ) and 12 age-matched healthy controls were examined by (dynamic) 31 P MRS (3 T system, 31 P/1 H coil). Phantoms (glucose-1-phosphate, Pi and PCr) were measured at pH values of 7.05 and 7.51. At rest, Pun signals with intensities higher than 50% of the Pi intensity were observed in 10 of the 68 examined diabetic subjects. We tested two hypothetical origins of the Pun signal: (1) phosphorus from phosphoesters and (2) phosphorus from extra- and intracellular alkaline phosphate pools. 2,3-diphosphoglycerate and glucose-1-phosphate are the only phosphoesters with signals in the chemical shift region close to 5.3 ppm. Both compounds can be excluded: 2,3-diphosphoglycerate due to the missing second signal component at 6.31 ppm; glucose-1-phosphate because its chemical shifts are about 0.2 ppm downfield from the Pi signal (4.9 ppm). If the Pun signal is from phosphate, it represents a pH value of 7.54 ± 0.05. Therefore, it could correspond to signals of Pi in mitochondria. However, patients with critical limb ischemia have rather few mitochondria and so the Pun signal probably originates from interstitia. Our data suggest that the increased Pun signal observed in patients with the diabetic foot syndrome is a biomarker of severe muscular damage.
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Extremidades/diagnóstico por imagem , Extremidades/patologia , Isquemia/diagnóstico por imagem , Espectroscopia de Ressonância Magnética , Fósforo/química , Processamento de Sinais Assistido por Computador , Idoso , Humanos , Concentração de Íons de Hidrogênio , Imagens de Fantasmas , DescansoRESUMO
BACKGROUND: Omega-3 (n-3) fatty acids (FA) play and important role in neural development and other metabolic diseases such as obesity and diabetes. The knowledge about the in vivo content and distribution of n-3 FA in human body tissues is not well established and the standard quantification of FA is invasive and costly. PURPOSE: To detect omega-3 (n-3 CH3 ) and non-omega-3 (CH3 ) methyl group resonance lines with echo times up to 1200 msec, in oils, for the assessment of n-3 FA content, and the n-3 FA fraction in adipose tissue in vivo. STUDY TYPE: Prospective technical development. POPULATION: Three oils with different n-3 FA content and 24 healthy subjects. FIELD STRENGTH/SEQUENCE: Single-voxel MR spectroscopy (SVS) with a point-resolved spectroscopy (PRESS) sequence with an echo time (TE) of 1000 msec at 7 T. ASSESSMENT: Knowledge about the J-coupling evolution of both CH3 resonances was used for the optimal detection of the n-3 CH3 resonance line at a TE of 1000 msec. The accuracy of the method in oils and in vivo was validated from a biopsy sample with gas chromatography analysis. STATISTICAL TESTS: SVS data were compared to gas chromatography with the Pearson correlation coefficient. RESULTS: T2 relaxation times in oils were assessed as follows: CH2 , 65 ± 22 msec; CH3 , 325 ± 7 msec; and n-3 CH3 , 628 ± 34 msec. The n-3 FA fractions from oil phantom experiments (n = 3) were in agreement with chromatography analysis and the comparison of in vivo obtained data with the results of chromatography analysis (n = 5) yielded a significant correlation (P = 0.029). DATA CONCLUSION: PRESS with ultralong-TE can detect and quantify the n-3 CH3 signal in vivo at 7 T. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:71-82.
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Ácidos Graxos Ômega-3/química , Espectroscopia de Ressonância Magnética , Gordura Subcutânea/diagnóstico por imagem , Adulto , Idoso , Simulação por Computador , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Imagens de Fantasmas , Estudos Prospectivos , Razão Sinal-RuídoRESUMO
Magnetic Resonance (MR) compatible ergometers are specialized ergometers used inside the MR scanners for the characterization of tissue metabolism changes during physical stress. They are most commonly used for dynamic phosphorous magnetic resonance spectroscopy (31P MRS), but can also be used for lactate production measurements, perfusion studies using arterial spin labelling or muscle oxygenation measurements by blood oxygen dependent contrast sequences. We will primarily discuss the importance of ergometers in the context of dynamic 31P MRS. Dynamic 31P MRS can monitor muscle fatigue and energy reserve during muscle contractions as well as the dynamics of recuperation of skeletal muscle tissue during the following recovery through signal changes of phosphocreatine (PCr), inorganic phosphate and adenosine triphosphate (ATP). Based on the measured data it is possible to calculate intracellular pH, metabolic flux of ATP through creatine-kinase reaction, anaerobic glycolysis and oxidative phosphorylation and other metabolic parameters as mitochondrial capacity. This review primarily focuses on describing various technical designs of MR compatible ergometers for dynamic 31P MRS that must be constructed with respect to the presence of magnetic field. It is also expected that the construction of ergometers will be easy for the handling and well accepted by examined subjects.
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AIM: The standard method for assessment of effect of revascularization in patients with diabetic foot (DF) and critical limb ischemia (CLI) is transcutaneous oxygen pressure (TcPO2). Phosphorus magnetic resonance spectroscopy (31P MRS) enables to evaluate oxidative muscle metabolism that could be impaired in patients with diabetes and its complications. The aim of our study was to compare MRS of calf muscle between patients with DF and CLI and healthy controls and to evaluate the contribution of MRS in the assessment of the effect of revascularization. METHODS: Thirty-four diabetic patients with DF and CLI treated either by autologous cell therapy (ACT; 15 patients) or percutaneous transluminal angioplasty (PTA; 12 patients) in our foot clinic during 2013-2016 and 19 healthy controls were included into the study. TcPO2 measurement was used as a standard method of non-invasive evaluation of limb ischemia. MRS examinations were performed using the whole-body 3T MR system 1 day before and 3 months after the procedure. Subjects were examined in a supine position with the coil fixed under the m. gastrocnemius. MRS parameters were obtained at rest and during the exercise period. Rest MRS parameters of oxidative muscle metabolism such as phosphocreatine (PCr), inorganic phosphate (Pi), phosphodiesters (PDE), adenosine triphosphate (ATP), dynamic MRS parameters such as recovery constant PCr (τPCr) and mitochondrial capacity (Qmax), and pH were compared between patients and healthy controls, and also before and 3 months after revascularization. RESULTS: Patients with CLI had significantly lower PCr/Pi (p < 0.001), significantly higher Pi and pH (both p < 0.01), significantly lower Qmax and prolonged τPCr (both p < 0.001) in comparison with healthy controls. We observed a significant improvement in TcPO2 at 3 months after revascularization (from 26.4 ± 11.7 to 39.7 ± 17.7 mm Hg, p < 0.005). However, the rest MRS parameters did not change significantly after revascularization. In individual cases we observed improvement of dynamic MRS parameters. There was no correlation between MRS parameters and TcPO2 values. CONCLUSION: Results of our study show impaired oxidative metabolism of calf muscles in patients with CLI in comparison with healthy controls. We observed an improvement in dynamic MRS parameters in individual cases; this finding should be verified in a large number of patients during longer follow-up.Key words: autologous cell therapy - critical limb ischemia - diabetic foot - MR spectroscopy.
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Pé Diabético/diagnóstico por imagem , Isquemia/diagnóstico por imagem , Músculo Esquelético/diagnóstico por imagem , Doenças Vasculares Periféricas/diagnóstico por imagem , Trifosfato de Adenosina/metabolismo , Idoso , Estudos de Casos e Controles , Pé Diabético/metabolismo , Pé Diabético/cirurgia , Exercício Físico/fisiologia , Feminino , Humanos , Isquemia/metabolismo , Isquemia/cirurgia , Perna (Membro)/irrigação sanguínea , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/metabolismo , Doenças Vasculares Periféricas/metabolismo , Doenças Vasculares Periféricas/cirurgia , Fosfatos/metabolismo , Fosfocreatina/metabolismo , Procedimentos Cirúrgicos VascularesRESUMO
BACKGROUND: Mycotic aortic aneurysm (MAA) is a rare and life-threatening disease. The aim of this European multicenter collaboration was to study the durability of endovascular aortic repair (EVAR) of MAA, by assessing late infection-related complications and long-term survival. METHODS AND RESULTS: All EVAR treated MAAs, between 1999 and 2013 at 16 European centers, were retrospectively reviewed. One hundred twenty-three patients with 130 MAAs were identified. Mean age was 69 years (range 39-86), 87 (71%) were men, 58 (47%) had immunodeficiency, and 47 (38%) presented with rupture. Anatomic locations were ascending/arch (n=4), descending (n=34), paravisceral (n=15), infrarenal aorta (n=63), and multiple (n=7). Treatments were thoracic EVAR (n=43), fenestrated/branched EVAR (n=9), and infrarenal EVAR (n=71). Antibiotic was administered for mean 30 weeks. Mean follow-up was 35 months (range 1 week to 149 months). Six patients (5%) were converted to open repair during follow-up. Survival was 91% (95% confidence interval, 86% to 96%), 75% (67% to 83%), 55% (44% to 66%), and 41% (28% to 54%) after 1, 12, 60, and 120 months, respectively. Infection-related death occurred in 23 patients (19%), 9 after discontinuation of antibiotic treatment. A Cox regression analysis demonstrated non-Salmonella-positive culture as predictors for late infection-related death. CONCLUSIONS: Endovascular treatment of MAA is feasible and for most patients a durable treatment option. Late infections do occur, are often lethal, and warrant long-term antibiotic treatment and follow-up. Patients with non-Salmonella-positive blood cultures were more likely to die from late infection.
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Aneurisma Infectado/microbiologia , Aneurisma Infectado/terapia , Aneurisma Aórtico/microbiologia , Aneurisma Aórtico/terapia , Procedimentos Endovasculares/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Aneurisma Infectado/epidemiologia , Antibacterianos/uso terapêutico , Aneurisma Aórtico/epidemiologia , Europa (Continente)/epidemiologia , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Estudos Retrospectivos , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/microbiologia , Infecção da Ferida Cirúrgica/mortalidade , Taxa de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: During and after exercise, dynamic 31 P MR parameters are typically measured using an MR-compatible ergometer. Self-built equipment for local condition can be constructed where possible. PURPOSE: To develop a pedal resistance ergometer with rocker arm based on a system that combines electric weight displacement, visual self-monitoring, and exercise triggering. The repeatability and reproducibility were tested. METHODS: The hardware and software for the ergometer were constructed from commercial components in a home laboratory. Twelve volunteers participated in the testing of the ergometer. RESULTS: A fully automated ergometer system was developed, allowing the pedal resistance to be adjusted during the examination. The system includes a self-monitoring and triggering mechanism that enables both the operator and subject to monitor pedal frequency and force. The operator can modify the pedal resistance as desired during the exercise. This self-monitoring solution is simple and cost-effective, requiring only a commercial potentiometer, an Arduino converter, and a conventional video projector with a personal computer (PC). Additionally, all system components are located outside the magnetic resonance (MR) room, avoiding interference with the MR system. Results of several test of the reproducibility/repeatability of power at three pedal resistance values (15%, 24%, 25% maximal voluntary force) were expressed both as a coefficient of variation ranging from 6% to 3.1% and as an intraclass correlation of coefficient ranging from 0.96 to 0.99. Similar values were also found for other dynamic parameters of 31 P MR spectroscopy. These findings are similar to published data obtained on different types of ergometers. CONCLUSIONS: Based on more than 1 year of usage, the ergometer proved successful in handling stationary and variable loads, and can be easily operated by a single user.
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Retroalimentação Sensorial , Imageamento por Ressonância Magnética , Humanos , Reprodutibilidade dos Testes , Espectroscopia de Ressonância Magnética/métodos , Exercício FísicoRESUMO
INTRODUCTION: Pancreatic steatosis (PS) has both metabolic consequences and local effects on the pancreas itself. Magnetic resonance imaging (MRI) is the most reliable non-invasive method for diagnosing PS. We investigated the impact of metabolic syndrome (MS) on the presence of PS, differences in individuals with and without PS, and the metabolic effects of bariatric procedures. METHODS: Changes in anthropometric and basic biochemistry values and MS occurrence were evaluated in 34 patients with obesity who underwent a bariatric procedure. After the procedure, patients underwent MRI with manual 3D segmentation mask creation to determine the pancreatic fat content (PFC). We compared the differences in the PFC and the presence of PS in individuals with and without MS and compared patients with and without PS. RESULTS: We found no significant difference in the PFC between the groups with and without MS or in the occurrence of PS. There were significant differences in patients with and without PS, especially in body mass index (BMI), fat mass, visceral adipose tissue (VAT), select adipocytokines, and lipid spectrum with no difference in glycemia levels. Significant metabolic effects of bariatric procedures were observed. CONCLUSIONS: Bariatric procedures can be considered effective in the treatment of obesity, MS, and some of its components. Measuring PFC using MRI did not show any difference in relation to MS, but patients who lost weight to BMI < 30 did not suffer from PS and had lower overall fat mass and VAT. Glycemia levels did not have an impact on the presence of PS.
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Cirurgia Bariátrica , Fígado Gorduroso , Síndrome Metabólica , Obesidade Mórbida , Humanos , Estudos Retrospectivos , Obesidade Mórbida/cirurgia , Pâncreas/diagnóstico por imagem , Pâncreas/metabolismo , Fígado Gorduroso/patologia , Imageamento por Ressonância Magnética/métodos , Gordura Intra-Abdominal/metabolismo , Obesidade/metabolismo , Síndrome Metabólica/diagnóstico por imagem , Síndrome Metabólica/metabolismoRESUMO
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. n-3 polyunsaturated fatty acids (n-3-PUFAs) have been reported to ameliorate the progression of NAFLD in experimental studies; however, clinical trials have yielded contradictory results. The aim of our study was to assess the effects of n-3-PUFA administration on lipid metabolism and the progression of NAFLD in patients with metabolic syndrome. Sixty patients with metabolic syndrome and NAFLD were randomized in a double-blind placebo-controlled trial (3.6 g/day n-3-PUFA vs. placebo). During the 1-year follow-up, the patients underwent periodic clinical and laboratory examinations, liver stiffness measurements, magnetic resonance spectroscopy of the liver, and plasma lipidomic analyses. After 12 months of n-3-PUFA administration, a significant decrease in serum GGT activity was recorded compared with the placebo group (2.03 ± 2.8 vs. 1.43 ± 1.6; P < 0.05). Although no significant changes in anthropometric parameters were recorded, a significant correlation between the reduction of liver fat after 12 months of treatment-and weight reduction-was observed; furthermore, this effect was clearly potentiated by n-3-PUFA treatment (P < 0.005). In addition, n-3-PUFA treatment resulted in substantial changes in the plasma lipidome, with n-3-PUFA-enriched triacylglycerols and phospholipids being the most expressed lipid signatures. Conclusion: Twelve months of n-3-PUFA treatment of patients with NAFLD patients was associated with a significant decrease in GGT activity, the liver fat reduction in those who reduced their weight, and beneficial changes in the plasma lipid profile.
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Ácidos Graxos Ômega-3 , Síndrome Metabólica , Hepatopatia Gordurosa não Alcoólica , Ácidos Graxos Ômega-3/uso terapêutico , Humanos , Metabolismo dos Lipídeos , Síndrome Metabólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológicoRESUMO
Minimally invasive surgery provides an attractive alternative compared with conventional surgical approaches and is popular with patients, particularly because of its favourable cosmetic results. Vascular surgery has taken its inspiration from general surgery and, over the past few years, has also been reducing the invasiveness of its operating methods. In addition to traditional laparoscopic techniques, we most frequently encounter the endovascular treatment of aneurysms of the thoracic and abdominal aorta and, most recently, robot-assisted surgery in the area of the abdominal aorta and pelvic arteries. Minimally invasive surgical interventions also have other advantages, including less operative trauma, a reduction in post-operative pain, shorter periods spent in the intensive care unit and overall hospitalization times, an earlier return to normal life and, finally, a reduction in total treatment costs.
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Aorta/cirurgia , Procedimentos Endovasculares , Artéria Femoral/cirurgia , Laparoscopia , Robótica , Procedimentos Cirúrgicos Vasculares , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos , Pelve/irrigação sanguínea , StentsRESUMO
Increased hepatic fat content (HFC) is a hallmark of non-alcoholic fatty liver (NAFL) disease, a common condition in liver transplant recipients. Proton MR spectroscopy (1H MRS) and MR imaging-based proton density fat fraction as the only diagnosis modality enable precise non-invasive measurement of HFC and, also, fatty acid profiles in vivo. Using 1H MRS at 3T, we examined 47 liver transplantation candidates and 101 liver graft recipients. A point-resolved spectroscopy sequence was used to calculate the steatosis grade along with the saturated, unsaturated and polyunsaturated fractions of fatty acids in the liver. The steatosis grade measured by MRS was compared with the histological steatosis grade. HFC, represented by fat fraction values, is adept at distinguishing non-alcoholic steatohepatitis (NASH), NAFL and non-steatotic liver transplant patients. Relative hepatic lipid saturation increases while unsaturation decreases in response to increased HFC. Additionally, relative hepatic lipid saturation increases while unsaturation and polyunsaturation both decrease in liver recipients with histologically proven post-transplant NASH or NAFL compared to non-steatotic patients. HFC, measured by in vivo 1H MRS, correlated well with histological results. 1H MRS is a simple and fast method for in vivo analysis of HFC and its composition. It provides non-invasive support for NAFL and NASH diagnoses.
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Critical limb ischemia in patients with diabetes at the organ complication stage represents a considerable challenge in vascular medicine. Because of the complexity of the disease and the often symmetric involvement of both lower limbs, a discrepancy between suitable vascular conduit availability and the actual requirement can occur: notably, the prevalence of multilevel and diffuse arterial disease often limits the possibilities of endovascular treatment, and, in surgical cases, frequently prohibits the effective use of prosthetic material. In our patient with bilateral critical limb ischemia and previous coronary artery bypass graft followed by cardiac transplantation, only one great saphenous vein remained available. That was used in its entirety to salvage one limb as a sequential femorocrural bypass. A similar surgical procedure with a fresh arterial allograft retrieved from a deceased donor was performed on the other extremity . ABO compatibility as well as the chronic immunosuppressive therapy in a heart transplant recipient may have contributed to the favorable long-term clinical outcome of the allogeneic arterial reconstruction.
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Angiopatias Diabéticas/cirurgia , Artéria Femoral/cirurgia , Transplante de Coração , Isquemia/cirurgia , Extremidade Inferior/irrigação sanguínea , Doença Arterial Periférica/cirurgia , Enxerto Vascular , Grau de Desobstrução Vascular , Artérias/transplante , Angiopatias Diabéticas/etiologia , Angiopatias Diabéticas/fisiopatologia , Feminino , Artéria Femoral/fisiopatologia , Humanos , Imunossupressores/administração & dosagem , Isquemia/etiologia , Isquemia/fisiopatologia , Angiografia por Ressonância Magnética , Pessoa de Meia-Idade , Doença Arterial Periférica/etiologia , Doença Arterial Periférica/fisiopatologia , Veia Safena/transplante , Fatores de Tempo , Transplante Homólogo , Resultado do TratamentoRESUMO
Extraskeletal osteochondroma is a benign, cartilaginous, slow-growing tumor with typical location near the joints of hands, feet, and knees. The authors present the case of a 44-year-old patient who experienced increasing pain in the right groin. Two isolated calcium deposits formed an encapsulated mass in the iliopsoas muscle, and the extraskeletal osteochondroma was diagnosed. An unusual location required that the operation be performed by a vascular surgeon. The authors present a wide range of groin-resistance differential diagnoses.
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Osteocondroma/diagnóstico , Neoplasias de Tecidos Moles/diagnóstico , Adulto , Artéria Femoral , Virilha , Humanos , Masculino , Osteocondroma/diagnóstico por imagem , Osteocondroma/cirurgia , Músculos Psoas , Neoplasias de Tecidos Moles/diagnóstico por imagem , Neoplasias de Tecidos Moles/cirurgia , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Diets rich in fat and added sugars (especially fructose) play an important role in the pathogenesis of nonalcoholic liver disease (NAFLD), but there is only limited information on the acute effects of these nutrients on hepatic fat content (HFC). OBJECTIVES: We therefore explored how the administration of high-fat load, glucose, fructose, and combinations thereof affects HFC measured in vivo using proton magnetic resonance spectroscopy (1H-MRS) in healthy subjects. METHODS: Ten healthy nonsteatotic male volunteers (age 38.5 ± 9.6 y, body mass index [BMI, kg/m2] 26.9 ± 2.7) underwent, in random order, 6 experiments, each lasting 8 h, that included: 1) fasting; 2) a high-fat load (150 g of fat [dairy cream] at time 0); 3) glucose (3 doses of 50 g at 0, 2, and 4 h); 4) a high-fat load with glucose; 5) fructose (3 doses of 50 g at 0, 2, and 4 h); and 6) a high-fat load with fructose. HFC was measured using 1H-MRS prior to test meal administration (before time 0) and at 3 and 6 h. Plasma concentrations of triglycerides, nonesterified fatty acids, glucose, and insulin were monitored throughout each experiment. RESULTS: HFC increased to 119 ± 19% (P < 0.05) and 117 ± 17% (P < 0.01) of baseline when subjects consumed a high-fat load alone or a high-fat load with fructose, respectively, but was not affected when glucose was coadministered with a high-fat load. HFC was not affected when subjects had fasted or had consumed repeated doses of fructose. When subjects were administered 3 doses of glucose, HFC dropped to 85 ± 13% (P < 0.05) of baseline. CONCLUSIONS: Our results demonstrate that fructose and glucose have a different immediate impact on HFC in humans in vivo. Clinical trial registry: The study was registered at clinicaltrials.gov and obtained clinicaltrials.gov identifier: NCT03680248.
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Frutose/metabolismo , Glucose/metabolismo , Fígado/metabolismo , Adolescente , Adulto , Gorduras/metabolismo , Ácidos Graxos não Esterificados/sangue , Humanos , Insulina/sangue , Masculino , Triglicerídeos/sangue , Adulto JovemRESUMO
BACKGROUND: Heart failure (HF) is often associated with iron deficiency (ID). Skeletal muscle abnormalities are common in HF, but the potential role of ID in this phenomenon is unclear. In addition to hemopoiesis, iron is essential for muscle bioenergetics. We examined whether energetic abnormalities in skeletal muscle in HF are affected by ID and if they are responsive to intravenous iron. METHODS AND RESULTS: Forty-four chronic HF subjects and 25 similar healthy volunteers underwent 31P magnetic resonance spectroscopy of calf muscle at rest and during exercise (plantar flexions). Results were compared between HF subjects with or without ID. In 13 ID-HF subjects, examinations were repeated 1 month after intravenous ferric carboxymaltose administration (1000 mg). As compared with controls, HF subjects displayed lower resting high-energy phosphate content, lower exercise pH, and slower postexercise PCr recovery. Compared with non-ID HF, ID-HF subjects had lower muscle strength, larger PCr depletion, and more profound intracellular acidosis with exercise, consistent with an earlier metabolic shift to anaerobic glycolysis. The exercise-induced PCr drop strongly correlated with pH change in HF group ( r=-0.71, P<0.001) but not in controls ( r=0.13, P=0.61, interaction: P<0.0001). Short-term iron administration corrected the iron deficit but had no effect on muscle bioenergetics assessed 1 month later. CONCLUSIONS: HF patients display skeletal muscle myopathy that is more severe in those with iron deficiency. The presence of ID is associated with greater acidosis with exercise, which may explain early muscle fatigue. Further study is warranted to identify the strategy to restore iron content in skeletal muscle.
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Metabolismo Energético , Teste de Esforço , Insuficiência Cardíaca/metabolismo , Deficiências de Ferro , Contração Isométrica , Espectroscopia de Ressonância Magnética/métodos , Músculo Esquelético/metabolismo , Isótopos de Fósforo , Acidose/metabolismo , Acidose/fisiopatologia , Administração Intravenosa , Adulto , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Metabolismo Energético/efeitos dos fármacos , Feminino , Compostos Férricos/administração & dosagem , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/fisiopatologia , Humanos , Ferro/sangue , Perna (Membro) , Masculino , Maltose/administração & dosagem , Maltose/análogos & derivados , Pessoa de Meia-Idade , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiopatologia , Valor Preditivo dos Testes , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: 31P-MR spectroscopy is a technique for undertaking a comprehensive evaluation of muscle metabolism. The goal of this study was to compare patients with mild and severe lower limb ischemia measured by 31P-MR spectroscopy at rest and during exercise. METHODS: Sixteen non-diabetic mild peripheral arterial occlusive disease (PAOD) patients, 23 diabetic PAOD patients with severe ischemia and 19 healthy controls were examined by rest and dynamic 31P-MR spectroscopy with a 3T MR system equipped with an MR-compatible home-made pedal ergometer. Signal intensity ratios of phosphorous metabolites to the sum of all 31P intensities (Ptot) and pH were obtained at rest. The PCr drop (ΔPCr), time recovery constant of PCr (τPCr), pH at the end of the exercise (pHend), and mitochondrial capacity (Qmax) were calculated from dynamic MR spectra. RESULTS: Diabetic PAOD patients with severe ischemia differed from controls in both rest (PCr/Pi, ßATP/Ptot, pH) and dynamic (Qmax, pHend, τPCr) parameters. PAOD patients with mild ischemia differed from controls only in Qmax and pHend. Rest parameters of the nondiabetic PAOD patients did not differ from control values excluding rest pH which was higher in both patient groups. CONCLUSIONS: A combination of rest and dynamic 31P-MR spectroscopy can distinguish among all three groups of subjects. On the other hand, examination at rest is sufficient for differentiation between patient groups and verification of severe ischemia.
Assuntos
Isquemia/complicações , Extremidade Inferior/irrigação sanguínea , Espectroscopia de Ressonância Magnética , Doenças Vasculares Periféricas/diagnóstico por imagem , Idoso , Estudos de Casos e Controles , Complicações do Diabetes , Exercício Físico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/irrigação sanguínea , DescansoRESUMO
PURPOSE: Dynamic phosphorus magnetic resonance spectroscopy ((31)P MRS) during and after acute exercise enables the noninvasive in vivo determination of the mitochondrial capacity of skeletal muscle. Nevertheless, the lack of standardization in experimental setups leads to significant variations in published values of maximal aerobic capacity, even in the population of healthy volunteers. Thus, in this study, we aimed to assess the impact of the ergometer type (pneumatic and mechanical resistance construction), radiofrequency (RF)-coil diameter, and different magnetic field strengths (3 and 7 T) on the metabolic parameters measured by dynamic (31)P MRS during a plantar flexion isotonic exercise protocol within the same group of healthy volunteers. METHODS: Dynamic (31)P MRS measurements of the calf muscle in 11 volunteers (mean age, 36 ± 13 yrs; mean BMI, 23.5 ± 2.5 kg/m(2)), on a 3 T MR system with a custom-made mechanical ergometer in the first research laboratory (RL1) and on 3 and 7 T MR systems equipped with a commercial pneumatic ergometer in the second research laboratory (RL2), were performed at three different workloads. RF-coils differed slightly between the sites and MR systems used. The repeatability of the experimental protocol was tested in every setup. The basal concentrations of phosphocreatine (PCr), exercise-induced depletion of PCr (ΔPCr), initial PCr resynthesis rate (VPCr), and mitochondrial capacity (Qmax) were calculated and compared between the research sites and field strengths. RESULTS: High repeatability of the measurement protocol was found in every experimental setup. No significant differences at any workload were found in these metabolic parameters assessed at different magnetic field strengths (3 T vs 7 T), using the same ergometer (in RL2) and a similar RF-coil. In the inter-research laboratory comparison at the same field strength (3 T), but with using different ergometers and RF-coils, differences were found in the concentration of PCr measured at rest and in the drop in PCr signal intensity. These differences translated into difference in the value of mitochondrial capacity at a workload of 15% of maximal voluntary contraction (MVC) force (0.45 ± 0.16 mM/s vs 0.31 ± 0.08 mM/s, in the RL1 and RL2, respectively). CONCLUSIONS: Metabolic parameters measured during exercise challenge by dynamic (31)P MRS do not depend upon the magnetic field strength used. For multicenter studies with different ergometers, it is important to set the same workload, measurement, and evaluation protocols, especially when the effects of very mild exercise (15% MVC) are to be compared. However, a higher workload (24% MVC) decreases the influence of imperfections and intersite differences for the assessed value of maximal mitochondrial capacity.