Cardiac function and ectopic adiposity in metabolic syndrome : an MRI and 1H-MRS study

Overweight and obesity are major global health concerns affecting around 2 billion people worldwide. Abdominal obesity is particularly hazardous to health associating with metabolic syndrome (MetS), non-alcoholic fatty liver disease (NAFLD), and type 2 diabetes mellitus (T2DM). In MetS, ectopic fat accumulates around the viscera and into organs regularly containing only minor amount of adipose tissue. This cross-sectional study was conceived to discover effects of MetS and ectopic adiposity including myocardial steatosis on cardiac function in non-diabetic men free of known heart diseases. The gold standard non-invasive method for fat quantification, proton magnetic resonance spectroscopy, was used to measure hepatic and myocardial triglyceride (TG) content. Magnetic resonance imaging (MRI) was used to assess cardiac structure and function and to quantify epicardial, pericardial, subcutaneous, and visceral abdominal fat depots. First, we examined the components of cardiac adiposity and their relationship to intra-abdominal ectopic fat deposits and cardiometabolic risk factors. MetS was associated with an increase in all examined ectopic fat depots. Myocardial TG was twofold increased in MetS. However, visceral adipose tissue (VAT) was the best independent predictor of cardiometabolic risk factors. Secondly, we studied left ventricular (LV) diastolic function and its relationship with cardiac fat depots. MetS associated with LV diastolic dysfunction and concentric LV remodeling. However, myocardial TG content was not an independent predictor of LV diastolic dysfunction. Thirdly, we studied the effect of different ectopic fat depots on LV structure and function in subjects with NAFLD and searched the role of hepatic fat content on cardiac steatosis. Epicardial and pericardial adipose tissue as well as myocardial TG content accumulated with increasing amount of both hepatic TG content and VAT. In addition, hepatic steatosis and VAT were associated with LV diastolic dysfunction. Lastly, we studied left atrial (LA) structure and function in MetS and examined the association of different ectopic fat depots and cardiometabolic risk factors with possible LA dysfunction. MetS associated with subclinical LA dysfunction without enlargement of the LA. Moreover, LA dysfunction associated with several contributory factors of MetS including waist circumference, insulin resistance, dyslipidemia, and VAT, which was the best independent predictor of LA dysfunction. Notably, the role of myocardial TG content on LA function remained inconclusive. In conclusion, MetS associates with significant changes in the structure and function of the heart. These changes are subclinical but may be followed by late complications such as heart failure or atrial fibrillation. The value of cardiovascular MRI may be early recognition of those obese subjects at risk for developing cardiovascular disease. Instead of body mass index, VAT is the best predictor of cardiac dysfunction. This study highlights the fundamental role of visceral obesity and hepatic steatosis directing their harmful effects to risk of cardiovascular diseases. The role of myocardial TG on cardiac dysfunction remains indeterminate. Therefore, cardiac energetics and the dynamic role of intramyocytic lipids, which are the primary fuel of the heart, merit further study.Ylipaino ja lihavuus ovat maailmanlaajuisia terveysongelmia koskettaen noin kahta miljardia ihmistä. Keskivartalolihavuus on erityisen haitallista terveydelle liitännäissairauksiensa kuten metabolisen oireyhtymän (MBO), alkoholiin liittymättömän rasvamaksataudin ja tyypin 2 diabeteksen vuoksi. MBO:ään liittyy rasvan kertyminen sisäelinten ympärille (viskeraalirasva) sekä varsinaisen rasvakudoksen ulkopuolelle (ektooppinen rasva) kuten sisäelimiin. Väitöskirjatyössä selvitettiin MBO:n vaikutuksia sydämen toimintaan ja sydämen rasvoittumisen roolia kardiometabolisena riskitekijänä miehillä, joilla ei ollut diabetesta tai tiedossa olevia sydäntauteja. Sydänlihaksen ja maksasolujen sisäistä rasva- eli triglyseridipitoisuutta mitattiin kajoamattomasti protonimagneettispektroskopian avulla. Sydämen rakennetta ja toimintaa, sydäntä ympäröivää epi- ja perikardiaalirasvaa sekä vatsan alueen ihonalais- ja viskeraalirasvaa tutkittiin magneettikuvauksella. Tutkimme maksan rasvoittumisen, ihonalais- ja viskeraalirasvan sekä sydämen eri rasvaosioiden suhdetta toisiinsa. Osoitimme, että MBO:ssä ektooppisen rasvan määrä oli kasvanut ja sydänlihaksen rasvapitoisuus oli kaksinkertainen. Viskeraalirasvan määrä oli paras itsenäinen kardiometabolisten riskitekijöiden ennustaja. Tutkimme sydämen vasemman kammion toimintaa ja sen yhteyttä sydämen rasvatiloihin. Sydämen vasemman kammion diastolinen toiminta oli alentunut MBO:ssä ja siihen liittyi konsentrista kammion uudelleenmuotoutumista. Vasemman kammion diastolisella vajaatoiminnalla ei ollut yhteyttä sydänlihaksen triglyseridipitoisuuteen. Tutkimme sydämen ja muiden ektooppisten rasvakertymien roolia sydämen diastolisen vajaatoiminnan kehittymisessä ja maksan rasvoittumisen yhteyttä sydänlihaksen triglyseridipitoisuuteen. Epi- ja perikardiaalirasvan määrä sekä sydänlihaksen triglyseridipitoisuus korreloivat maksan ja viskeraalialueen rasvaan. Maksan rasvoittumisaste ja viskeraalirasvan määrä korreloivat lisäksi sydämen vasemman kammion diastoliseen vajaatoimintaan. Selvitimme sydämen vasemman eteisen rakennetta ja toimintaa henkilöillä, joilla oli MBO, ja ektooppisten rasvakertymien sekä kardiovaskulaaristen riskitekijöiden vaikutusta niihin. Sydämen vasemman eteisen toiminta oli heikentynyt ilman eteisen koon muutosta. Vasemman eteisen vajaatoiminta oli yhteydessä useaan MBO:n osatekijään, kuten vyötärönympärys, insuliiniresistenssi, rasva-aineenvaihdunnan häiriöt ja viskeraalirasvan määrä, joista viimeksi mainittu oli paras itsenäinen ennustetekijä. Eteisen vajaatoiminta ei korreloinut sydänlihaksen rasvan määrään. Löysimme sydämen magneettikuvauksella MBO-potilailta merkittäviä sydämen rakenteen ja toiminnan piileviä muutoksia, joiden mahdollisia myöhäis-komplikaatiota ovat sydämen vajaatoiminta ja eteisvärinä. Viskeraalirasvan määrä oli paras ennustetekijä piileville sydämen toiminnan häiriöille. Viskeraalirasvalla ja rasvamaksalla on tärkeä rooli lihavuuden haitallisten sydänvaikutusten systeemisenä välittäjänä. Osoitimme, että sydämen triglyseridipitoisuus lisääntyy MBO:ssä ja alkoholiin liittymättömässä rasvamaksataudissa, mutta sen rooli sydämen toiminnan häiriöiden kehittymisessä jäi avoimeksi. Sydämen energiatalous ja sydämen pääenergialähteenä toimivien lipidien dynaaminen rooli ovat otollisia kohteita jatkotutkimuksille

Cardiac steatosis and left ventricular function in men with metabolic syndrome

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Cardiac steatosis associates with visceral obesity in nondiabetic obese men.

Background: Liver fat and visceral adiposity are involved in the development of the metabolic syndrome (MetS). Ectopic fat accumulation within and around the heart has been related to increased risk of heart disease. The aim of this study was to explore components of cardiac steatosis and their relationship to intra-abdominal ectopic fat deposits and cardiometabolic risk factors in nondiabetic obese men. Methods: Myocardial and hepatic triglyceride (TG) contents were measured with 1.5 T magnetic resonance spectroscopy, and visceral adipose (VAT), abdominal subcutaneous tissue (SAT), epicardial and pericardial fat by magnetic resonance imaging in 37 men with the MetS and in 40 men without the MetS. Results: Myocardial and hepatic TG contents, VAT, SAT, epicardial fat volumes, and pericardial fat volumes were higher in men with the MetS compared with subjects without the MetS (P < .001). All components of cardiac steatosis correlated with SAT, VAT, and hepatic TG content and the correlations seemed to be strongest with VAT. Myocardial TG content, epicardial fat, pericardial fat, VAT, and hepatic TG content correlated with waist circumference, body mass index, high-density lipoprotein cholesterol TGs, very low-density lipoprotein-1 TGs, and the insulin-resistance homeostasis model assessment index. VAT was a predictor of TGs, high-density lipoprotein cholesterol, and measures of glucose metabolism, whereas age and SAT were determinants of blood pressure parameters. Conclusions: We suggest that visceral obesity is the best predictor of epicardial and pericardial fat in abdominally obese subjects. Myocardial TG content may present a separate entity that is influenced by factors beyond visceral adiposity

Biomarkers and prediction of myocardial triglyceride content in non-diabetic men

Background and aims: Lipid oversupply to cardiomyocytes or decreased utilization of lipids leads to cardiac steatosis. We aimed to examine the role of different circulating metabolic biomarkers as predictors of myocardial triglyceride (TG) content in non-diabetic men. Methods and results: Myocardial and hepatic TG contents were measured with 1.5 T magnetic resonance (MR) spectroscopy, and LV function, visceral adipose tissue (VAT), abdominal subcutaneous tissue (SAT), epicardial and pericardial fat by MR imaging in 76 non-diabetic men. Serum concentration of circulating metabolic biomarkers [adiponectin, leptin, adipocyte-fatty acid binding protein 4 (A-FABP 4), resistin, and lipocalin-2] including beta-hydroxybuturate (beta-OHB) were measured. Subjects were stratified by tertiles of myocardial TG into low, moderate, and high myocardial TG content groups. Concentrations of beta-OHB were lower (p = 0.003) and serum levels of A-FABP 4 were higher (p <0.001) in the group with high myocardial TG content compared with the group with low myocardial TG content. beta-OHB was negatively correlated with myocardial TG content (r = -0.316, p = 0.006), whereas A-FABP 4 was not correlated with myocardial TG content (r = 0.192, p = 0.103). In multivariable analyses beta-OHB and plasma glucose levels were the best predictors of myocardial TG content independently of VAT and hepatic TG content. The model explained 58.8% of the variance in myocardial TG content. Conclusion: Our data showed that beta-OHB and fasting glucose were the best predictors of myocardial TG content in non-diabetic men. These data suggest that hyperglycemia and alterations in lipid oxidation may be associated with cardiac steatosis in humans. (C) 2015 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.Peer reviewe

Characterization of different fat depots in NAFLD using inflammation-associated proteome, lipidome and metabolome

Non-alcoholic fatty liver disease (NAFLD) is recognized as a liver manifestation of metabolic syndrome, accompanied with excessive fat accumulation in the liver and other vital organs. Ectopic fat accumulation was previously associated with negative effects at the systemic and local level in the human body. Thus, we aimed to identify and assess the predictive capability of novel potential metabolic biomarkers for ectopic fat depots in non-diabetic men with NAFLD, using the inflammation-associated proteome, lipidome and metabolome. Myocardial and hepatic triglycerides were measured with magnetic spectroscopy while function of left ventricle, pericardial and epicardial fat, subcutaneous and visceral adipose tissue were measured with magnetic resonance imaging. Measured ectopic fat depots were profiled and predicted using a Random Forest algorithm, and by estimating the Area Under the Receiver Operating Characteristic curves. We have identified distinct metabolic signatures of fat depots in the liver (TAG50:1, glutamate, diSM18:0 and CE20:3), pericardium (N-palmitoyl-sphinganine, HGF, diSM18:0, glutamate, and TNFSF14), epicardium (sphingomyelin, CE20:3, PC38:3 and TNFSF14), and myocardium (CE20:3, LAPTGF-beta 1, glutamate and glucose). Our analyses highlighted non-invasive biomarkers that accurately predict ectopic fat depots, and reflect their distinct metabolic signatures in subjects with NAFLD.Peer reviewe

Changes in occurrence and management of laryngeal fractures at the Helsinki University Hospital during 25 years

PurposeLaryngeal fracture is a rare but potentially life-threatening trauma. Fractures vary from mild to dislocated and extensive with risk of severe complications. This study investigated the occurrence, clinical characteristics and management of laryngeal fractures in the last 15 years.Material and methodsA retrospective population-based cohort study reviewing all laryngeal fractures at the Helsinki University Hospital in 2005-2019. Patient records and imaging studies were systematically reviewed for mode of injury, fracture type, secondary complications, treatment modality, possible airway management, length of stay, and mortality. Results were compared with corresponding data from 1995 to 2004.ResultsOverall 80 fracture patients were recorded (5.3/year); 79% were men and mean age was 42 years (range 18-78). Altogether 91% were closed and 9% open. While unintentional traumas were most common (54%), an increasing proportion were from intentional injury (10%) or Schaefer Gr IV in severity (35%). Altogether 46% had compromised airway and 21% needed airway intervention; airway narrowing was more common with cricoid (p = 0.042) and multiple fractures (p = 0.07) and correlated positively with amount of dislocation (p = 0.001) and number of fracture lines (p = 0.006). Surgery was performed for 33%, of which 46% were Schaefer Gr IV and 62% from intentional trauma. Mortality was 1.4%.ConclusionsDeliberate and violence-related laryngeal fractures have increased. These often result in more extensive injuries predisposing to compromised airway and requiring surgical intervention and longer treatment. Most fractures are still treated conservatively with good long-term outcomes. An observation period of 24 h is recommended to detect any delayed complications. Mortality remains low.Peer reviewe

OXYFINES Technique for Upgrading Zinc Containing Blast Furnace Sludge—Part 1: Pilot Trials

In the Swedish steel industry, much work is put on further increasing the recycling and use of residual materials. However, blast furnace sludge is one residual which currently, despite its valuable contents of iron and carbon, is put on landfill or long-term storage due to its zinc content. Linde has developed the OXYFINES technique which is suitable for upgrading of fine particulate and zinc containing materials. The material is fed to the OXYFINES burner whereby its zinc content is vaporised to a generated dust phase whereas other non-gasifiable contents, such as iron, forms an oxidic sinter phase in the bottom of the reactor. The technique has proven a high degree of zinc separation, is relatively flexible and straightforward, and does not require sludge pre-treatment such as drying. Pilot set-up and trials, using the OXYFINES technique, were performed at Swerim&rsquo;s research facility. In the trials, the effects from altering different process parameters were tested aiming to develop an optimal concept for upgrading the blast furnace sludge. The pilot trials&rsquo; results showed the required process settings to attain a high degree of zinc separation from the sludge, and to generate an iron oxide product, suitable for straightforward charging to the steelmaking process

Assessment of subjective image quality, contrast to noise ratio and modulation transfer function in the middle ear using a novel full body cone beam computed tomography device

BackgroundMulti slice computed tomography (MSCT) is the most common used method in middle ear imaging. However, MSCT lacks the ability to distinguish the ossicular chain microstructures in detail resulting in poorer diagnostic outcomes. Novel cone beam computed tomography (CBCT) devices' image resolution is, on the other hand, better than MSCT resolution. The aim of this study was to optimize imaging parameters of a novel full body CBCT device to obtain optimal contrast to noise ratio (CNR) with low effective dose, and to optimize its clinical usability.MethodsImaging of five anonymous excised human cadaver temporal bones, the acquisition of the effective doses and the CNR measurements were performed for images acquired on using Planmed XFI (R) full body CBCT device (Planmed Oy, Helsinki, Finland) with a voxel size of 75 mu m. All images acquired from the specimens using 10 different imaging protocols varying from their tube current exposure time product (mAs) and tube voltage (kVp) were analyzed for eight anatomical landmarks and evaluated by three evaluators.ResultsWith the exception of protocol with 90 kVp 100 mAs, all other protocols used are competent to image the finest structures. With a moderate effective dose (86.5 mu Sv), protocol with 90 kV 450 mAs was chosen the best protocol used in this study. A significant correlation between CNR and clinical image quality of the protocols was observed in linear regression model. Using the optimized imaging parameters, we were able to distinguish even the most delicate middle ear structures in 2D images and produce accurate 3D reconstructions.ConclusionsIn this ex vivo experiment, the new Planmed XFI (R) full body CBCT device produced excellent 2D resolution and easily created 3D reconstructions in middle ear imaging with moderate effective doses. This device would be suitable for middle ear diagnostics and for e.g., preoperative planning. Furthermore, the results of this study can be used to optimize the effective dose by selecting appropriate exposure parameters depending on the diagnostic task.Peer reviewe