Liver Fat (liver + fat)

Distribution by Scientific Domains
Distribution within Medical Sciences

Terms modified by Liver Fat

  • liver fat content

  • Selected Abstracts


    Liver fat is reproducibly measured using computed tomography in the Framingham Heart Study

    JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 6 2008
    Elizabeth K Speliotes
    Abstract Background and Aims:, Fatty liver is the hepatic manifestation of obesity, but community-based assessment of fatty liver among unselected patients is limited. We sought to determine the feasibility of and optimal protocol for quantifying fat content in the liver in the Framingham Heart Study using multidetector computed tomography (MDCT) scanning. Methods:, Participants (n = 100, 49% women, mean age 59.4 years, mean body mass index 27.8 kg/m2) were drawn from the Framingham Heart Study cohort. Two readers measured the attenuation of the liver, spleen, paraspinal muscles, and an external standard from MDCT scans using multiple slices in chest and abdominal scans. Results:, The mean measurement variation was larger within a single axial computed tomography (CT) slice than between multiple axial CT slices for the liver and spleen, whereas it was similar for the paraspinal muscles. Measurement variation in the liver, spleen, and paraspinal muscles was smaller in the abdomen than in the chest. Three versus six measures of attenuation in the liver and two versus three measures in the spleen gave reproducible measurements of tissue attenuation (intraclass correlation coefficient [ICCC] of 1 in the abdomen). Intrareader and interreader reproducibility (ICCC) of the liver-to-spleen ratio was 0.98 and 0.99, the liver-to-phantom ratio was 0.99 and 0.99, and the liver-to-muscle ratio was 0.93 and 0.86, respectively. Conclusion:, One cross-sectional slice is adequate to capture the majority of variance of fat content in the liver per individual. Abdominal scan measures as compared to chest scan measures of fat content in the liver are more precise. The measurement of fat content in the liver on MDCT scans is feasible and reproducible. [source]


    Liver fat and lipid oxidation in humans

    LIVER INTERNATIONAL, Issue 9 2009
    Anna Kotronen
    Abstract Background: Studies in animals show that changes in hepatic fatty acid oxidation alter liver fat content. Human data regarding whole-body and hepatic lipid oxidation are controversial and based on studies of only a few subjects. Aims: We examined whether whole-body and hepatic lipid oxidation are altered in subjects with non-alcoholic fatty liver disease (NAFLD) compared with controls. Methods: In vivo measurements of rates of substrate oxidation and insulin sensitivity (using the euglycaemic hyperinsulinaemic clamp technique in combination with indirect calorimetry and infusion of [3- 3H]glucose) were performed in subjects with NAFLD [mean liver fat 14.0% (interquartile range 7.5,20.5%), n=29] and in control subjects [1.6% (1.0,3.0%), n=29]. Liver fat was measured using proton magnetic resonance spectroscopy. Plasma concentrations of 3-hydroxybutyrate (3-OHB) were measured as markers of hepatic lipid oxidation. Results: In the basal state, substrate oxidation rates and serum 3-OHB concentrations were comparable in subjects with and without NAFLD. Plasma 3-OHB concentrations were similarly suppressed by insulin in both the groups. During the insulin infusion, whole-body lipid oxidation was inversely correlated with insulin-stimulated glucose disposal (r=,0.48, P<0.0001), which was lower in subjects with NAFLD [3.7±0.2 mg/(kg fat-free mass min)] than in the control subjects [5.0±0.3 mg/(kg fat-free mass min), P=0.0008]. Conclusions: Hepatic lipid oxidation is unchanged in NAFLD. Whole-body lipid oxidation is increased because of peripheral insulin resistance. These data imply that alterations in hepatic fatty acid oxidation do not contribute to liver fat content in humans. [source]


    Lifestyle intervention in individuals with normal versus impaired glucose tolerance

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 7 2007
    S. Schäfer
    Abstract Background, Lifestyle intervention is effective in the prevention of type 2 diabetes in individuals with impaired glucose tolerance (IGT). It is currently unknown whether it has beneficial effects on metabolism to a similar extent, in individuals with normal glucose tolerance (NGT) compared to individuals with IGT. Materials and methods, Data from 181 subjects (133 with NGT and at risk for type 2 diabetes and 48 with IGT) who participated in the Tuebingen Lifestyle Intervention Program with increase in physical activity and decrease in caloric intake were included into this study. Body fat distribution was quantified by whole-body magnetic resonance (MR) tomography and liver fat and intramyocellular fat by 1H-MR spectroscopy. Insulin sensitivity was estimated from an oral glucose tolerance test (OGTT). Results, After 9 ± 2 months of follow-up, the diagnosis of IGT was reversed in 24 out of 48 individuals. Only 14 out of 133 participants with NGT developed IGT. Body weight decreased in both groups by 3% (both P < 0·0001). Two-hour glucose concentrations during an OGTT decreased in individuals with IGT (,14%, P < 0·0001) but not with NGT (+2%, P = 0·66). Insulin sensitivity increased both in individuals with IGT (+9%, P = 0·04) and NGT (+17%, P < 0·0001). Visceral fat (,8%, P = 0·006), liver fat (,28%, P < 0·0001) and intramyocellular fat (,15%, P = 0·006) decreased in participants with IGT. In participants with NGT these changes were significant for visceral fat (,16%, P < 0·0001) and liver fat (,35%, P < 0·0001). Conclusions, Moderate weight loss under a lifestyle intervention with reduction in total, visceral and ectopic fat and increase in insulin sensitivity improves glucose tolerance in individuals with IGT but not with NGT. In individuals with NGT, the beneficial effects of a lifestyle intervention on fat distribution and insulin sensitivity possibly prevent future deterioration in glucose tolerance. [source]


    Fitness versus fatness: Moving beyond weight loss in nonalcoholic fatty liver disease,,

    HEPATOLOGY, Issue 1 2010
    Nathan A. Johnson
    The rapid emergence of nonalcoholic fatty liver disease (NAFLD) as a cause of both liver-related morbidity and mortality and cardiometabolic risk has led to the search for effective lifestyle strategies to reduce liver fat. Lifestyle intervention comprising dietary restriction in conjunction with increased physical activity has shown clear hepatic benefits when weight loss approximating 3%-10% of body weight is achieved. Yet, the poor sustainability of weight loss challenges the current therapeutic focus on body weight and highlights the need for alternative strategies for NAFLD management. Epidemiologic data show an independent relationship between liver fat, physical activity, and fitness, and a growing body of longitudinal research demonstrates that increased physical activity participation per se significantly reduces hepatic steatosis and serum aminotransferases in individuals with NAFLD, independent of weight loss. Mechanistic insights to explain this interaction are outlined, and recommendations for the implementation of lifestyle intervention involving physical activity are discussed. In light of the often poor sustainability of weight loss strategies, and the viability of physical activity therapy, clinicians should assess physical fitness and physical activity habits, educate patients on the benefits of fitness outside of weight loss, and focus on behavior change which promotes physical activity adoption. (HEPATOLOGY 2010) [source]


    Prevention of diet-induced fatty liver in experimental animals by the oral administration of a fatty acid bile acid conjugate (FABAC)

    HEPATOLOGY, Issue 2 2003
    Tuvia Gilat
    Fatty acid bile acid conjugates (FABACs) are a new family of synthetic molecules designed to solubilize biliary cholesterol. They were shown to prevent and dissolve cholesterol gallstones in inbred C57L/J mice fed a lithogenic, high-fat diet (HFD). In these mice, fatty liver was observed in the controls but not in the FABAC-treated ones. The present study was designed to study the effect of FABAC (arachidyl-amido-cholanoic acid) on diet-induced fatty liver in rats, hamsters, and mice. The fatty liver score (on a scale of 0-4 by light microscopy) was 4.0 in control hamsters and 0.3 in the FABAC-fed hamsters (P < .001). In mice it was 1.5 and 0.4, respectively (P < .01). The lipid/protein ratio in the liver was 1.3 ± 0.44 (mg lipid/mg protein) in control rats and 0.66 ± 0.04 in the FABAC group (P = .001) after 14 days. In hamsters it was 1.41 ± 0.27 and 1.11 ± 0.20, respectively (P = .03), after 21 days. In Imperial Charles River (ICR) mice the ratio was 0.34 ± 0.10 and 0.17 ± 0.07 (P = .03), respectively, after 24 days. Liver fat concentration, measured as mg lipid/g liver tissue, decreased similarly by FABAC feeding. The decrease in liver fat affected mainly the triglyceride levels. FABAC-fed animals gained weight similarly to the controls. Triglyceride absorption was unaffected by FABAC supplementation. In conclusion, oral FABAC therapy prevents/reduces the development of fatty liver in animals consuming a HFD. [source]


    Nitric Oxide-Mediated Intestinal Injury Is Required for Alcohol-Induced Gut Leakiness and Liver Damage

    ALCOHOLISM, Issue 7 2009
    Yueming Tang
    Background:, Alcoholic liver disease (ALD) requires endotoxemia and is commonly associated with intestinal barrier leakiness. Using monolayers of intestinal epithelial cells as an in vitro barrier model, we showed that ethanol-induced intestinal barrier disruption is mediated by inducible nitric oxide synthase (iNOS) upregulation, nitric oxide (NO) overproduction, and oxidation/nitration of cytoskeletal proteins. We hypothesized that iNOS inhibitors [NG-nitro- l -arginine methyl ester (l -NAME), l -N6 -(1-iminoethyl)-lysine (l -NIL)] in vivo will inhibit the above cascade and liver injury in an animal model of alcoholic steatohepatitis (ASH). Methods:, Male Sprague,Dawley rats were gavaged daily with alcohol (6 g/kg/d) or dextrose for 10 weeks ± l -NAME, l -NIL, or vehicle. Systemic and intestinal NO levels were measured by nitrites and nitrates in urine and tissue samples, oxidative damage to the intestinal mucosa by protein carbonyl and nitrotyrosine, intestinal permeability by urinary sugar tests, and liver injury by histological inflammation scores, liver fat, and myeloperoxidase activity. Results:, Alcohol caused tissue oxidation, gut leakiness, endotoxemia, and ASH. l -NIL and l -NAME, but not the d -enantiomers, attenuated all steps in the alcohol-induced cascade including NO overproduction, oxidative tissue damage, gut leakiness, endotoxemia, hepatic inflammation, and liver injury. Conclusions:, The mechanism we reported for alcohol-induced intestinal barrier disruption in vitro , NO overproduction, oxidative tissue damage, leaky gut, endotoxemia, and liver injury , appears to be relevant in vivo in an animal model of alcohol-induced liver injury. That iNOS inhibitors attenuated all steps of this cascade suggests that prevention of this cascade in alcoholics will protect the liver against the injurious effects of chronic alcohol and that iNOS may be a useful target for prevention of ALD. [source]


    A phase 2 clinical trial of metformin as a treatment for non-diabetic paediatric non-alcoholic steatohepatitis

    ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 7 2005
    J. B. Schwimmer
    Summary Background :,Children with non-alcoholic steatohepatitis are insulin-resistant and metformin has been proposed as a potential therapy. However, paediatric safety and efficacy data are absent. Aim :,To test the hypothesis that metformin therapy will safely improve markers of liver disease in paediatric non-alcoholic steatohepatitis. Methods :,Single-arm open-label pilot study of metformin 500 mg twice daily for 24 weeks in non-diabetic children with biopsy-proven non-alcoholic steatohepatitis. Results :,Ten obese children (mean body mass index 30.4) enrolled and completed the trial. Mean alanine aminotransferase and aspartate aminotransferase (AST) improved significantly (P < 0.01) from baseline (184, 114 U/L) to end of treatment (98, 68 U/L). Alanine aminotransferase normalized in 40% and AST normalized in 50% of subjects. Children demonstrated significant improvements in liver fat measured by magnetic resonance spectroscopy (30,23%, P < 0.01); insulin sensitivity measured by quantitative insulin sensitivity check index (0.294,0.310, P < 0.05); and quality of life measured by pediatric quality of life inventory 4.0 (69,81, P < 0.01). Conclusion :,Open-label treatment with metformin for 24 weeks was notable for improvement in liver chemistry, liver fat, insulin sensitivity and quality of life. A large randomized-controlled trial is needed to definitively determine the efficacy of metformin for paediatric non-alcoholic steatohepatitis. [source]


    Quantitative ATP synthesis in human liver measured by localized 31P spectroscopy using the magnetization transfer experiment

    NMR IN BIOMEDICINE, Issue 5 2008
    A. I. Schmid
    Abstract The liver plays a central role in intermediate metabolism. Accumulation of liver fat (steatosis) predisposes to various liver diseases. Steatosis and abnormal muscle energy metabolism are found in insulin-resistant and type-2 diabetic states. To examine hepatic energy metabolism, we measured hepatocellular lipid content, using proton MRS, and rates of hepatic ATP synthesis in vivo, using the 31P magnetization transfer experiment. A suitable localization scheme was developed and applied to the measurements of longitudinal relaxation times (T1) in six healthy volunteers and the ATP-synthesis experiment in nine healthy volunteers. Liver 31P spectra were modelled and quantified successfully using a time domain fit and the AMARES (advanced method for accurate, robust and efficient spectral fitting of MRS data with use of prior knowledge) algorithm describing the essential components of the dataset. The measured T1 relaxation times are comparable to values reported previously at lower field strengths. All nine subjects in whom saturation transfer was measured had low hepatocellular lipid content (1.5,±,0.2% MR signal; mean,±,SEM). The exchange rate constant (k) obtained was 0.30,±,0.02,s,1, and the rate of ATP synthesis was 29.5,±,1.8,mM/min. The measured rate of ATP synthesis is about three times higher than in human skeletal muscle and human visual cortex, but only about half of that measured in perfused rat liver. In conclusion, 31P MRS at 3,T provides sufficient sensitivity to detect magnetization transfer effects and can therefore be used to assess ATP synthesis in human liver. Copyright © 2007 John Wiley & Sons, Ltd. [source]