Noninvasive in vivo quantitative assessment of fat content in human liver

Risk factors for development of nonalcoholic fatty liver disease after pancreatoduodenectomy

Considerable attention has been focused on nonalcoholic fatty liver disease (NAFLD) which occasionally develops after pancreatoduodenectomy (PD). The present study aimed to clarify the prevalence, sequential change in properties and risk factors for NAFLD development after PD. We enrolled 196 patients who underwent PD and a computed tomography (CT) scan 1 month, 6 months and 1 year after surgery. NAFLD was defined as a liver‐to‐spleen attenuation ratio on plain CT of <0.9. We compared various clinical factors between the NAFLD group and the control group. Individual prevalence of NAFLD at 1 month, 6 months and 1 year after surgery was 12%, 21% and 15%. Significantly different factors by univariate analysis were as follows: 1 month: age, sex, total protein (TP), total cholesterol (TC) and copper (Cu); 6 months: sex, disease, surgical method, portal vein resection (PVR), frequency of defecation, TC and Cu; 1 year: age, sex, disease, surgical method, PVR, frequency of defecation, TP and Cu. Risk factors by multivariate analysis were as follows: 1 month: not elderly age, female sex and a decrease in Cu; 6 months: female sex and a decrease in Cu; 1 year: a decrease in Cu. NAFLD after PD frequently developed in women with a decrease in serum Cu and was influenced by various factors related to poor digestion and absorption associated with pancreatic exocrine insufficiency.

Association of the Composite Inflammatory Biomarker GlycA, with Exercise-Induced Changes in Body Habitus in Men and Women with Prediabetes

GlycA is a new composite measure of systemic inflammation and a predictor of many inflammatory diseases. GlycA is the nuclear magnetic resonance spectroscopy-derived signal arising from glucosamine residues on acute-phase proteins. This study aimed to evaluate how exercise-based lifestyle interventions modulate GlycA in persons at risk for type 2 diabetes. GlycA, fitness, and body habitus were measured in 169 sedentary adults (45–75 years) with prediabetes randomly assigned to one of four six-month exercise-based lifestyle interventions. Interventions included exercise prescription based on the amount (energy expenditure (kcal/kg weight/week (KKW)) and intensity (%VO_2peak). The groups were (1) low-amount/moderate-intensity (10KKW/50%) exercise; (2) high-amount/moderate-intensity (16KKW/50%) exercise; (3) high-amount/vigorous-intensity (16KKW/75%) exercise; and (4) a Clinical Lifestyle (combined diet plus low-amount/moderate-intensity exercise) intervention. Six months of exercise training and/or diet-reduced GlycA (mean Δ: −6.8 ± 29.2 μmol/L; p = 0.006) and increased VO_2peak (mean Δ: 1.98 ± 2.6 mL/kg/min; p < 0.001). Further, visceral (mean Δ: −21.1 ± 36.6 cm²) and subcutaneous fat (mean Δ: −24.3 ± 41.0 cm²) were reduced, while liver density (mean Δ: +2.3 ± 6.5HU) increased, all p < 0.001. When including individuals in all four interventions, GlycA reductions were associated with reductions in visceral adiposity (p < 0.03). Exercise-based lifestyle interventions reduced GlycA concentrations through mechanisms related to exercise-induced modulations of visceral adiposity. This trial is registered with Clinical Trial Registration Number NCT00962962.

New exponential functions based on CT density to estimate the percentage of liver that is fat

OBJECTIVE

In fluorine-18 fludeoxyglucose positron emission tomography/CT, hepatic standardized uptake value (SUV) is reduced through "signal dilution" by hepatic fat. The maximum SUV (SUV_max) is less affected than the mean SUV (SUV_mean), therefore SUV_max/SUV_mean correlates with hepatic fat. The SUV can be corrected for signal dilution using an equation relating CT density (CTD) to %fat. The objective was to exploit the relationship between SUV indices and CTD to assess the validity of two previously published equations (one linear and one sigmoid) for estimating %fat from CTD and two new exponential equations.

METHODS

Study population comprised 465 patients having routine fluorine-18 fludeoxyglucose positron emission tomography/CT. The SUV_max, SUV_mean and CTD were measured from a 3-cm-diameter region of interest over the liver. The exponential equations assumed that 100% fat corresponds to CTD of -50 or -100 HU. The proportion of liver occupied by fat (P_F) was estimated from all four equations. Then fat-corrected SUV_mean is SUV_mean/(1 - P_F). The ideal equation should give SUV_mean approaching but not exceeding SUV_max and give fat-corrected SUV_mean/SUV_max that shows no correlation with CTD.

RESULTS

The linear equation failed at CTD values exceeding 55.8 HU because it gave negative P_F values. Moreover, fat-corrected SUV_mean/SUV_max still correlated with CTD. The sigmoid equation grossly overcorrected SUV_mean at low CTD. The exponential equations abolished the correlation between fat-corrected SUV_mean/SUV_max and CTD.

CONCLUSION

The sigmoid equation is unsuitable for estimating %fat from CTD. The linear equation performed well, but the exponential equation assuming that 100% fat corresponds to -50 HU performed best. Advances in knowledge: Improved (exponential) equations to estimate hepatic fat from hepatic CTD.

Imaging patterns and focal lesions in fatty liver: a pictorial review

Non-alcoholic fatty liver disease is the most common cause of chronic liver disease and affects nearly one-third of US population. With the increasing trend of obesity in the population, associated fatty change in the liver will be a common feature observed in imaging studies. Fatty liver causes changes in liver parenchyma appearance on imaging modalities including ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) and may affect the imaging characteristics of focal liver lesions (FLLs). The imaging characteristics of FLLs were classically described in a non-fatty liver. In addition, focal fatty change and focal fat sparing may also simulate FLLs. Knowledge of characteristic patterns of fatty change in the liver (diffuse, geographical, focal, subcapsular, and perivascular) and their impact on the detection and characterization of FLL is therefore important. In general, fatty change may improve detection of FLLs on MRI using fat suppression sequences, but may reduce sensitivity on a single-phase (portal venous) CT and conventional ultrasound. In patients with fatty liver, MRI is generally superior to ultrasound and CT for detection and characterization of FLL. In this pictorial essay, we describe the imaging patterns of fatty change in the liver and its effect on detection and characterization of FLLs on ultrasound, CT, MRI, and PET.

A Pilot Comparative Study of Quantitative Ultrasound, Conventional Ultrasound, and MRI for Predicting Histology-Determined Steatosis Grade in Adult Nonalcoholic Fatty Liver Disease

OBJECTIVE

The purpose of this study is to explore the diagnostic performance of two investigational quantitative ultrasound (QUS) parameters, attenuation coefficient and backscatter coefficient, in comparison with conventional ultrasound (CUS) and MRI-estimated proton density fat fraction (PDFF) for predicting histology-confirmed steatosis grade in adults with nonalcoholic fatty liver disease (NAFLD).

SUBJECTS AND METHODS

In this prospectively designed pilot study, 61 adults with histology-confirmed NAFLD were enrolled from September 2012 to February 2014. Subjects underwent QUS, CUS, and MRI examinations within 100 days of clinical-care liver biopsy. QUS parameters (attenuation coefficient and backscatter coefficient) were estimated using a reference phantom technique by two analysts independently. Three-point ordinal CUS scores intended to predict steatosis grade (1, 2, or 3) were generated independently by two radiologists on the basis of QUS features. PDFF was estimated using an advanced chemical shift-based MRI technique. Using histologic examination as the reference standard, ROC analysis was performed. Optimal attenuation coefficient, backscatter coefficient, and PDFF cutoff thresholds were identified, and the accuracy of attenuation coefficient, backscatter coefficient, PDFF, and CUS to predict steatosis grade was determined. Interobserver agreement for attenuation coefficient, backscatter coefficient, and CUS was analyzed.

RESULTS

CUS had 51.7% grading accuracy. The raw and cross-validated steatosis grading accuracies were 61.7% and 55.0%, respectively, for attenuation coefficient, 68.3% and 68.3% for backscatter coefficient, and 76.7% and 71.3% for MRI-estimated PDFF. Interobserver agreements were 53.3% for CUS (κ = 0.61), 90.0% for attenuation coefficient (κ = 0.87), and 71.7% for backscatter coefficient (κ = 0.82) (p < 0.0001 for all).

CONCLUSION

Preliminary observations suggest that QUS parameters may be more accurate and provide higher interobserver agreement than CUS for predicting hepatic steatosis grade in patients with NAFLD.

The extent to which standardized uptake values reflect FDG phosphorylation in the liver and spleen as functions of time after injection of 18F-fluorodeoxyglucose

Purpose

In FDG PET/CT, standardized uptake value (SUV) is used to measure metabolic activity but detects un-phosphorylated FDG as well as phosphorylated FDG (FDG6P). Our aim was to determine the proportions of intrahepatic and intrasplenic FDG that are phosphorylated after FDG injection and compare them with SUVs.

Methods

Sixty patients undergoing whole-body PET/CT 60 min post-injection of FDG first had dynamic PET imaging for 30 min with measurement of hepatic and splenic FDG clearances using Patlak-Rutland analysis. The gradient of the Patlak-Rutland plot, which is proportional to clearance (Ki), was normalized to the intercept, which is proportional to FDG distribution volume (V(0)) with the same proportionality constant. Using measured values of Ki/V(0), FDG6P/FDG ratios as functions of time in the two organs were measured for assumed FDG blood disappearance half-times of 40, 50 and 60 min. Hepatic and splenic SUVs were measured from whole-body PET/CT.

Results

The mean (SD) Ki/V(0) was 0.0036 (0.0021) and 0.0060 (0.0041) ml/min/ml for the liver and spleen, respectively, but the hepatic SUV was 1.36-fold higher than the splenic SUV. This discrepancy was explained by the hepatic V(0) being 1.6-fold higher than the splenic V(0). The percentages of FDG phosphorylated 60 min post-injection were 27, 25 and 23% for the liver and 39, 36 and 34% for the spleen, for blood clearance half-times of 40, 50 and 60 min, respectively. SUV indices correlated poorly with Ki/V(0) for both organs.

Conclusions

SUV is largely determined by un-phosphorylated FDG in dynamic exchange with blood FDG, explaining the poor correlations between SUV indices and Ki/V(0).

Short- and Long-Term Reproducibility of Intrahepatic Lipid Quantification by 1H-MR Spectroscopy and CT in Obesity

OBJECTIVE

This study aimed to assess short- and long-term reproducibility of intrahepatic lipid (IHL) quantification by proton magnetic resonance spectroscopy (H-MRS) and computed tomography (CT).

METHODS

Sixteen obese subjects underwent H-MRS using a single-voxel point-resolved single-voxel spectroscopy sequence at 3 T and noncontrast single-slice CT of the liver. Measurements were repeated after 6 weeks and 6 months. Clinical parameters (weight, activity, serum lipids) were collected. Short-term (baseline to 6 weeks) and long-term (baseline to 6 months) reproducibility of IHL was assessed by coefficient of variance (CV), SD, and intraclass correlation coefficient (ICC).

RESULTS

Short-term reproducibility and long-term reproducibility of H-MRS were as follows: CV, 5.9% to 18.8%; SD, 0.7 to 1.9; and ICC, 0.998 to 0.995 (95% confidence interval, 0.942-0.999). Short-term reproducibility and long-term reproducibility of CT were as follows: CV, 4.4% to 14.2%; SD, 2.4 to 8.7; and ICC, 0.766 to 0.982 (95% confidence interval, 0.271-0.994). There was no significant change in clinical parameters (P > 0.3).

CONCLUSIONS

Proton magnetic resonance spectroscopy and CT are reproducible methods for short- and long-term quantification of IHL content. Our results can guide sample size calculations for interventional and longitudinal studies.

Non-invasive imaging techniques in assessing non-alcoholic fatty liver disease: a current status of available methods

Non-alcoholic fatty liver disease (NAFLD) is an ailment affecting and increasing a number of people worldwide diagnosed via non-invasive imaging techniques, at a time when a minimum harm caused by medical procedures is rightfully emphasized, more sought after, than ever before. Liver steatosis should not be taken lightly even if its evolution is largely benign as it has the potential to develop into non-alcoholic steatohepatitis (NASH) or even more concerning, hepatic cirrhosis, and hepatocellular carcinoma (HCC). Traditionally, liver biopsy has been the standard for diagnosing this particular liver disease, but nowadays, a consistent number of imagistic methods are available for diagnosing hepatosteatosis and choosing the one appropriate to the clinical context is the key. Although different in sensitivity and specificity when it comes to determining the hepatic fat fraction (FF), these imaging techniques possessing a diverse availability, operating difficulty, cost, and reproducibility are invaluable to any modern physician. Ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), elastography, and spectroscopy will be discussed in order to lay out the advantages and disadvantages of their diagnostic potential and application.

Although imagistics has given physicians a valuable insight into the means of managing NAFLD, the current methods are far from perfect, but given the time, they will surely be improved and the use of liver biopsy will be completely removed.

Lack of Independent Association Between Fatty Pancreas and Incidence of Type 2 Diabetes: 5-Year Japanese Cohort Study

OBJECTIVE

Previous cross-sectional studies have shown that attenuation in the pancreas seen on unenhanced computed tomography (CT) scans was inversely correlated with histologic pancreatic fat, and that fatty pancreas was associated with type 2 diabetes mellitus (T2DM). However, no longitudinal study has evaluated whether fatty pancreas increases the incidence of T2DM. We conducted a cohort study to investigate the association between fatty pancreas and the incidence of T2DM.

RESEARCH DESIGN AND METHODS

A total of 813 participants without diabetes underwent health checks by unenhanced CT scanning in 2008 and 2009, and were observed for a median follow-up period of 5.06 (interquartile range 3.01-5.92) years. Attenuation in three regions of the pancreas seen on an unenhanced CT scan was measured, and the mean pancreatic attenuation was calculated to evaluate fatty pancreas at baseline; the more severe the fatty pancreas, the lower the mean pancreatic attenuation. The incident T2DM hazard ratios (HRs) for the association between fatty pancreas and T2DM incidence were estimated by Cox proportional hazards models adjusted for age, sex, BMI, liver attenuation seen on unenhanced CT scan, and alcohol intake of ≥20 g/day.

RESULTS

T2DM occurred in 62 participants (7.6%) during the follow-up period. The higher pancreas attenuation (i.e., less pancreatic fat) at baseline was associated with decreased T2DM incidence in a univariate analysis (crude HR 0.97 [95% CI 0.96-0.99]); and fatty pancreas (lower pancreas attenuation) was positively associated with increased T2DM incidence. However, the association was substantially explained by the confounders (multivariate HR 1.00 [95% CI 0.98-1.02]).

CONCLUSIONS

Fatty pancreas was not independently associated with future T2DM.

Usefulness of Magnetic Resonance Imaging for the Diagnosis of Hemochromatosis with Severe Hepatic Steatosis in Nonalcoholic Fatty Liver Disease

The ratio of the number of patients with non-alcoholic steatohepatitis (NASH) to the total number of patients with liver dysfunction has increased in many countries around the world. Liver dysfunction is also caused by multiple blood transfusions in patients with leukemia and other hematological diseases, with liver dysfunction often accompanied by secondary hemochromatosis. This study describes a 25-year-old man with secondary hemochromatosis combined with NASH. Magnetic resonance imaging was useful for visualizing the distributions of both iron and fat in the liver of this patient in order to make a differential diagnosis and to evaluate the effect of treatment.

Association of non-alcoholic fatty liver disease with renal stone disease detected on computed tomography

Objective

To evaluate the association between Non-alcoholic fatty liver disease (NAFLD) with renal stone disease detected on computed tomography (CT).

Method

A total 1812 patients who underwent abdomen-pelvis CT in July 2015 were included in this study. The inclusion criteria for NAFLD were as follows: (i) lower average Hounsfield unit (HU) of hepatic right lobe, left medial and lateral segment when compared with that of spleen, (ii) patients who having urolithiasis in kidneys, ureters and urinary bladder, and (iii) patients underwent abdomen-pelvis CT including noncontrast image. The statistical significance of the association between NAFLD and renal stone disease was assessed using Chi Square Test. The Odds ratios and 95% CI were calculated to assess the propensity of renal stones disease for NAFLD by using Logistic Regression analysis.

Results

The frequency of renal stone disease in patients with NAFLD was higher approximately 19% than those who having renal stone disease without NAFLD. In addition, the presence of NAFLD was linked with renal stone disease showing that detection rate of renal stone disease in patients with NAFLD was markedly high (odds ratio: 5, 95% CI, 3–8.2) (p < 0.05) in multivariate analysis.

Conclusion

The presence of significant association between NAFLD with renal stone disease and NAFLD may be considered to be an independent variable as a risk factor for renal stone disease.

Predictive value of serum dihomo-γ-linolenic acid level and estimated Δ-5 desaturase activity in patients with hepatic steatosis

BACKGROUND

Hepatic steatosis is considered one of the features of metabolic syndrome (MetS). Polyunsaturated fatty acid (PUFA) metabolism is modulated in obesity. However, it has yet to be fully elucidated whether a serum PUFA profile is associated with hepatic steatosis.

OBJECTIVE

We aimed to clarify the relationship between a serum PUFA profile and liver lipid content.

METHODS

A cross-sectional study was conducted on 288 patients with dyslipidemia, diabetes, or coronary artery disease on statin therapy. Several PUFAs were measured, including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), dihomo-γ-linolenic acid (DGLA) and arachidonic acid (AA) in serum lipids, and Δ-5 desaturase (D5D) activity was estimated by AA to DGLA ratio. Abdominal computed tomography (CT) measured visceral fat area (VFA) and the ratio of CT attenuation for liver to spleen (L/S).

RESULTS

The L/S ratio showed significant correlations with serum DGLA level and D5D activity (p<0.0001 for both). Serum DGLA level and D5D activity were significantly correlated with body mass index (BMI) or VFA, and with Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) (p<0.0001 for all). Multivariate logistic analysis revealed that a high DGLA level or low D5D activity was a significant determinant for hepatic steatosis (p<0.0001 for both) independent of BMI and HOMA-IR. ROC analysis revealed that they significantly enhanced the value of MetS-related factors in predicting hepatic steatosis (p<0.05 for both).

CONCLUSIONS

A high DGLA level and low D5D activity in serum lipids may be useful markers predicting hepatic steatosis incrementally to MetS-related conventional factors.

Clinical Characteristics and Risk Factors for the Development of Postoperative Hepatic Steatosis After Total Pancreatectomy

OBJECTIVES

The occurrence of hepatic steatosis after pancreatectomy is known to be associated with the remnant pancreatic function. However, other risk factors for hepatic steatosis after pancreatectomy remain unknown. The aims of this study were to identify other risk factors in addition to the remnant pancreatic function and elucidate the relationship between postoperative hepatic steatosis and pancreatic exocrine insufficiency in totally pancreatomized patients.

METHODS

Forty-three patients who underwent total pancreatectomy were analyzed. Hepatic steatosis was defined as the attenuation of unenhanced computed tomography values. Clinical findings and laboratory data were compared between patients with and without hepatic steatosis.

RESULTS

Sixteen (37.2%) patients developed hepatic steatosis after total pancreatectomy, with marked declines in the Controlling Nutritional Status score and body mass index. Multiple linear regression analysis revealed that the attenuation of computed tomography values was correlated with female sex (P = 0.002), early postoperative serum albumin levels (P = 0.003), and pancreatic enzyme replacement therapy with high-dose pancrelipase (P = 0.032).

CONCLUSIONS

Postoperative hepatic steatosis after pancreatectomy is associated with sex, malnutrition, and pancreatic exocrine insufficiency. High-dose pancreatic enzyme replacement therapy may have preventive effects on hepatic steatosis occurring after pancreatectomy.

Perioperative Computed Tomography Assessments of the Pancreas Predict Nonalcoholic Fatty Liver Disease After Pancreaticoduodenectomy

Nonalcoholic fatty liver disease (NAFLD) after pancreaticoduodenectomy (PD) has become a clinically important issue. Although pancreatic exocrine insufficiency has been reported to be a main cause of NAFLD after PD, a clinically practical examination to assess the pancreatic exocrine function has not been established. The aim of this study was to evaluate risk factors for NAFLD after PD with a focus on perioperative computed tomography (CT) assessments of the pancreas.A retrospective review of 245 patients followed for more than 6 months after PD was conducted. We evaluated several pancreatic CT parameters, including the pancreatic parenchymal thickness, pancreatic duct-to-parenchymal ratio, pancreatic attenuation, and remnant pancreatic volume (RPV) on pre- and/or postoperative CT around 6 months after surgery. The variables, including the pancreatic CT parameters, were compared between the groups with and without NAFLD after PD.The incidence of NAFLD after PD was 19.2%. A multivariate analysis identified 5 independent risk factors for NAFLD after PD: a female gender (odds ratio [OR] 5.66, P < 0.001), RPV < 12 mL (OR 4.73, P = 0.001), preoperative pancreatic attenuation of <30 Hounsfield units (OR 4.50, P = 0.002), dissection of the right-sided nerve plexus around the superior mesenteric artery (OR 3.02, P = 0.017) and a preoperative serum carbohydrate antigen 19-9 level of ≥70 U/mL (OR 2.58, P = 0.029).Our results showed that 2 pancreatic CT parameters, the degree of preoperative pancreatic attenuation and RPV, significantly influence the development of NAFLD after PD. Perioperative CT assessments of the pancreas may be helpful for predicting NAFLD after PD.

Impact of body fat distribution on neoadjuvant chemotherapy outcomes in advanced breast cancer patients

Obesity is known to decrease the efficacy of neoadjuvant chemotherapy (NAC) against breast cancer; however, the relationship between actual body composition and NAC outcomes remains unknown. Therefore, we determined the effect of body composition on NAC outcomes. A total of 172 advanced breast cancer patients who underwent surgery after NAC were retrospectively analyzed. Body composition parameters including abdominal circumference (AC), subcutaneous fat area (SFA), visceral fat area (VFA), and skeletal muscle area (SMA) were calculated using computed tomography volume‐analyzing software. VFA/SFA ratio was used to evaluate visceral obesity. The associations of body composition parameters with pathological complete remission (pCR) and survival were analyzed. AC, SFA, and VFA were significantly correlated with body mass index (BMI) (all P < 0.05; r = 0.82, r = 0.71, and r = 0.78, respectively). AC, SFA, and VFA increased significantly and SMA decreased significantly after menopause (all P < 0.05). VFA/SFA ratio increased significantly after menopause, even though BMI remained unchanged. Body composition parameters were not associated with pCR. Distant disease‐free survival (DDFS) was significantly worse in the high VFA group than in the low VFA group (P < 0.05). Furthermore, in the high VFA group, postmenopausal patients had significantly shorter DDFS than premenopausal patients (P < 0.05). VFA was independently associated with DDFS in the multivariate analysis (P < 0.05). High visceral fat is associated with worse NAC outcomes in breast cancer patients, especially postmenopausal patients. Interventions targeting visceral fat accumulation will likely improve NAC outcomes.

Accuracy of dual-energy computed tomography for the quantification of iodine in a soft tissue-mimicking phantom

The objective of this study was to evaluate the accuracy of dual-energy CT (DECT) for quantifying iodine using a soft tissue-mimicking phantom across various DECT acquisition parameters and dual-source CT (DSCT) scanners. A phantom was constructed with plastic tubes containing soft tissue-mimicking materials with known iodine concentrations (0-20 mg/mL). Experiments were performed on two DSCT scanners, one equipped with an integrated detector and the other with a conventional detector. DECT data were acquired using two DE modes (80 kV/Sn140 kV and 100 kV/Sn140 kV) with four pitch values (0.6, 0.8, 1.0, and 1.2). Images were reconstructed using a soft tissue kernel with and without beam hardening correction (BHC) for iodine. Using the dedicated DE software, iodine concentrations were measured and compared to true concentrations. We also investigated the effect of reducing gantry rotation time on the DECT-based iodine measurement. At iodine concentrations higher than 10 mg/mL, the relative error in measured iodine concentration increased slightly. This error can be decreased by using the kernel with BHC, compared with the kernel without BHC. Both 80 kV/Sn140 kV and 100 kV/Sn140 kV modes could provide accurate quantification of iodine content. Increasing pitch value or reducing gantry rotation time had only a minor impact on the DECT-based iodine measurement. The DSCT scanner, equipped with the new integrated detector, showed more accurate iodine quantification for all iodine concentrations higher than 10 mg/mL. An accurate quantification of iodine can be obtained using the second-generation DSCT scanner in various DE modes with pitch values up to 1.2 and gantry rotation time down to 0.28 s. For iodine concentrations ≥ 10 mg/mL, using the new integrated detector and the kernel with BHC can improve the accuracy of DECT-based iodine measurements.

Liver fat, statin use, and incident diabetes: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

To balance competing cardiovascular benefits and metabolic risks of statins, markers of type 2 diabetes (T2D) susceptibility are needed. We sought to define a competing risk/benefit of statin therapy on T2D and cardiovascular disease (CVD) events using liver attenuation and coronary artery calcification (CAC).

METHODS AND RESULTS

3153 individuals from the Multi-Ethnic Study of Atherosclerosis (MESA) without CVD, T2D/impaired fasting glucose, or baseline statin therapy had CT imaging for CAC and hepatic attenuation (hepatic steatosis). Cox models and rates of CVD and T2D were calculated to assess the role of liver attenuation in T2D and the relative risks/benefits of statins on CVD and T2D. 216 T2D cases were diagnosed at median 9.1 years follow-up. High liver fat and statin therapy were associated with diabetes (HR 2.06 [95%CI 1.52-2.79, P < 0.0001] and 2.01 [95%CI 1.46-2.77, P < 0.0001], respectively), after multivariable adjustment. With low liver fat and CAC = 0, the number needed to treat (NNT) for statin to prevent one CVD event (NNT 218) was higher than the number needed to harm (NNH) with an incident case of T2D (NNH 68). Conversely, those with CAC >100 and low liver fat were more likely to benefit from statins for CVD reduction (NNT 29) relative to T2D risk (NNH 67). Among those with CAC >100 and fatty liver, incremental reduction in CVD with statins (NNT 40) was less than incremental risk increase for T2D (NNH 24).

CONCLUSIONS

Liver fat is associated with incident T2D and stratifies competing metabolic/CVD risks with statin therapy. Hepatic fat may inform T2D surveillance and lipid therapeutic strategies.

The Assessment of Hepatosteatosis in Living-Donor Liver Transplant: Comparison of Liver Attenuation Index and Histopathologic Results

OBJECTIVES

The purpose of the study was to determine the diagnostic value of computed tomography densitometry in the quantification of hepatosteatosis.

MATERIALS AND METHODS

Fifty-one potential liver donors, ranging in age from 19 to 52 years (mean age: 32.4 years ± 10.2), participated in the study. The mean hepatic attenuation and mean splenic attenuation were determined using regions of interest measurements. The difference between the mean hepatic attenuation and mean splenic attenuation (or liver attenuation index), with liver attenuation index = mean hepatic attenuation - mean splenic attenuation were calculated. Computed tomography densitometric parameters were correlated with histopathologic results.

RESULTS

From the histopathologic analysis, the degree of macrovesicular hepatosteatosis was 0% to 8% (mean: 1.1% ± 2%). Seven donors (13.7%) had a degree of macrovesicular steatosis of > 5%, and 12 donors (23.5%) had ≥ 2%. Of the 29 normal donors with histopathologic verification, computed tomography densitometry predicted ≤ 5% of the hepatosteatosis in 27 donors, and ≤ 2% hepatosteatosis in 2 subjects. The liver attenuation index was significantly correlated to the histopathologic results. The mathematical relation between liver attenuation index and the degree of histopathologic hepatosteatosis was calculated using the least-squares methods, which provided quadratic polynomials.

CONCLUSIONS

Computed tomography densitometry is a rapid, robust, noninvasive technique for the assessment of hepatosteatosis. When used in conjunction with clinically stable reference measurements of spleen, the density measurements of liver correctly predicted the presence of fatty infiltration with significant sensitivity (77%) and specificity (75%). This technique, which was refined during the course of our liver transplant program, minimizes the need for highly invasive percutaneous liver biopsies.

Combined Adiponectin Deficiency and Resistance in Obese Patients: Can It Solve Part of the Puzzle in Nonalcoholic Steatohepatitis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has become the most prevalent cause of liver disease, nonalcoholic steatohepatitis (NASH) and fibrosis in obese patients identifies the risk group with increased incidence of liver-related deaths.

AIM

To clarify the role of serum adiponectin and its receptor liver gene expression in the progression of liver damage in NAFLD.

METHODS

Fifty four (54) obese patients with NAFLD preliminary diagnosed by liver ultra-sound were recruited. Full medical history, anthropometric measurement, biochemical studies, serum adiponectin level, liver biopsy for histological examination and NAS score to identify NASH patients, and assessment of adiponectin receptor gene expression by RT-PCR, were conducted for each patients. Fifteen ages matched average weight healthy adult had been chosen as a control for serum adiponectin level.

RESULTS

According to NAS score, patients were divided into non- NASH (8 patients), and NASH (46 patients). Serum adiponectin level was significantly lower in NAFLD patients compared to normal participants (p < 0.004). Serum adiponectin level was lower in NASH patients (4.437 ± 2.569 ng/dl in NASH vs. 5.138 ± 2.841 ng/dl in non-NASH). Adiponectin receptor liver gene expression was lower in NASH patients (0.8459 ± 0.4671 vs. 1.0688 ± 0.3965 in non-NASH).

CONCLUSION

Both adiponectin deficiency and resistance had a role in progression of simple liver steatosis to severe injury in obese patients.

Nonalcoholic Steatohepatitis and Hepatic Fibrosis in HIV-1-Monoinfected Adults With Elevated Aminotransferase Levels on Antiretroviral Therapy

BACKGROUND

Persistent aminotransferase elevations are common in human immunodeficiency virus (HIV)-infected patients on antiretroviral therapy (ART), including those without hepatitis B or C coinfection, but their clinical significance is unknown.

METHODS

HIV-infected adults with aminotransferase levels elevated above the upper limit of normal for ≥6 months while receiving ART, and without chronic viral hepatitis or other known causes of chronic liver disease, underwent a detailed metabolic assessment and liver biopsy.

RESULTS

Sixty-two HIV-infected subjects completed the study. Forty (65%) had clinically significant liver pathology, including 34 (55%) with nonalcoholic steatohepatitis (NASH) and 11 (18%) with bridging fibrosis, 10 of whom also had NASH. Nonspecific abnormalities alone were seen in 22 (35%) subjects, including mild steatosis, mild to moderate inflammation, and evidence of drug adaptation. Insulin resistance, obesity, and the presence of either of 2 minor alleles in the PNPLA3 gene were significantly associated with increased risk of NASH and fibrosis. NASH and/or fibrosis were not associated with duration of HIV infection or ART, specific antiretroviral drugs, history of opportunistic infection, immune status, or duration of aminotransferase elevation.

CONCLUSIONS

HIV-infected adults with chronic aminotransferase elevations while receiving ART have a high rate of liver disease. Noninvasive testing can help identify liver disease in such patients, but liver biopsy is necessary to definitively identify those at risk for liver disease progression and complications. Longitudinal follow-up of this cohort will better characterize the natural history of aminotransferase elevations in this population and identify noninvasive biomarkers of liver disease progression.

Liver steatosis and the risk of albuminuria: the multi-ethnic study of atherosclerosis

OBJECTIVE

To measure association between hepatic fat and albuminuria (an early marker of renal injury) in individuals without diabetes or hypertension.

METHODS

2,281 individuals in the Multi-Ethnic Study of Atherosclerosis without diabetes or hypertension, renal disease, or excess alcohol consumption underwent computed tomography (CT) for assessment of liver attenuation (marker of hepatic lipid content) and urinalysis (for albuminuria) at initial study visit, with assessment of incident and prevalent albuminuria by logistic regression in follow-up.

RESULTS

After adjustment for age, gender, race, smoking, blood pressure, insulin resistance, and body mass index, individuals with less liver fat (higher liver CT attenuation) had a lower probability of having albuminuria at Exam 1 (OR per 10 unit increase in attenuation 0.77, 95 % CI 0.61-0.97, P = 0.02). At median 9.3 years follow-up, albuminuria was identified in 129 individuals were (5.8 %). In fully adjusted models (with age, smoking, body mass index, blood pressure, diabetes and hypertension as time-dependent covariates), lower liver attenuation (greater liver fat) was associated with higher risk of incident albuminuria (OR 0.79, 95 % CI 0.66-0.94, P = 0.008).

CONCLUSIONS

Hepatic attenuation is associated with prevalent and incident albuminuria, an early, potent risk factor for renal risk in a population not clearly at risk for future renal failure.

Non-invasive assessment of liver steatosis in non-alcoholic fatty liver disease

AIM

The diagnosis of non-alcoholic fatty liver disease (NAFLD) is based on the histological findings. Further, there may be interobserver differences. Liver to spleen (L/S) ratio on computed tomography (CT) is employed to detect or even quantify the fat content of the liver. The objective of this study was to accurately diagnose fatty liver by evaluating the relationship between L/S ratio and histological findings.

METHODS

Sixty-seven biopsy-proven NAFLD patients were enrolled. L/S ratio on CT was calculated. The area of steatosis in liver specimens was measured by BIOREVO BZ-9000 microscope, and the percentage of steatosis was calculated using Dynamic cell count BZ-H1C software.

RESULTS

Steatotic grade assessed by pathologist was significantly correlated with the percentage of steatosis and L/S ratio. Factors associated with steatosis were L/S ratio, aspartate aminotransferase and Homeostasis Model of Assessment - Insulin Resistance as determined by multivariate analysis. L/S ratios were: S0, 1.16 ± 0.20 (mean ± standard deviation); S1, 0.88 ± 0.28; S2, 0.76 ± 0.20; and S3, 0.40 ± 0.18, respectively. The optimal cut-off value of L/S ratio to exclude steatosis was 1.1, and the area under the receiver-operator curve for the diagnosis of steatosis was 0.886.

CONCLUSION

Our study suggests that while 0% of steatosis showed 1.296 L/S ratio, the cut-off value of L/S ratio would be 1.1 at least to exclude clinically important liver steatosis.

Type 2 diabetes mellitus is associated with the fibrosis severity in patients with nonalcoholic fatty liver disease in a large retrospective cohort of Japanese patients

BACKGROUND

The prevalence of nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome have been increasing worldwide. The associations between metabolic factors and the histologic severity of NAFLD have not yet been clarified. Therefore, we studied the relationships between relevant metabolic factors and the histological severity of NAFLD.

METHODS

In a cross-sectional multicenter study conducted in Japan, we examined 1,365 biopsy-proven NAFLD patients. The frequencies of underlying lifestyle-related diseases and their relationships to the NAFLD histology were investigated.

RESULTS

The hepatic fibrosis stages (Stage 0/1/2/3/4) were 22.6/34.1/26.7/14.5/2.1 (%) in the male patients, and 16.2/31.7/23.9/21.6/6.6 (%) in the female patients. Dyslipidemia was present in 65.7% (hypertriglyceridemia, 45.3%; increased low-density lipoprotein cholesterol, 37.5%; decreased high density lipoprotein cholesterol, 19.5%) of patients. Hypertension was present in 30.2%, and diabetes mellitus (DM) in 47.3%. The fibrosis stage increased with age, especially in postmenopausal females. The body mass index was positively correlated with the fibrosis stage. Deterioration of glucose control was positively correlated with the fibrosis stage, this correlation being more prominent in females. Multivariate analysis identified age and DM as significant risk factors for advanced fibrosis. No significant correlation of the fibrosis stage was observed with hypertension. There was a negative correlation between the serum triglyceride levels and the fibrosis stage.

CONCLUSIONS

DM appeared to be a significant risk factor for advanced fibrosis in patients with NAFLD, and would therefore need to be properly managed to prevent the progression of NAFLD.

A prospective, randomized study on hepatotoxicity of anastrozole compared with tamoxifen in women with breast cancer

Tamoxifen and anastrozole are widely used as adjuvant treatment for early stage breast cancer, but their hepatotoxicity is not fully defined. We aimed to compare hepatotoxicity of anastrozole with tamoxifen in the adjuvant setting in postmenopausal breast cancer patients. Three hundred and fifty-three Chinese postmenopausal women with hormone receptor-positive early breast cancer were randomized to anastrozole or tamoxifen after optimal primary therapy. The primary end-point was fatty liver disease, defined as a liver–spleen ratio <0.9 as determined using a computed tomography scan. The secondary end-points included abnormal liver function and treatment failure during the 3-year follow up. The cumulative incidence of fatty liver disease after 3 years was lower in the anastrozole arm than that of tamoxifen (14.6% vs 41.1%, P < 0.0001; relative risk, 0.30; 95% CI, 0.21–0.45). However, there was no difference in the cumulative incidence of abnormal liver function (24.6% vs 24.7%, P = 0.61). Interestingly, a higher treatment failure rate was observed in the tamoxifen arm compared with anastrozole and median times to treatment failure were 15.1 months and 37.1 months, respectively (P < 0.0001; HR, 0.27; 95% CI, 0.20–0.37). The most commonly reported adverse events were ‘reproductive system disorders’ in the tamoxifen group (17.1%), and ‘musculoskeletal disorders’ in the anastrozole group (14.6%). Postmenopausal women with hormone receptor-positive breast cancer receiving adjuvant anastrozole displayed less fatty liver disease, suggesting that this drug had a more favorable hepatic safety profile than tamoxifen and may be preferred for patients with potential hepatic dysfunction.

Impact of rosiglitazone on body composition, hepatic fat, fatty acids, adipokines and glucose in persons with impaired fasting glucose or impaired glucose tolerance: a sub-study of the DREAM trial

AIMS

Thiazolidinediones reduce ectopic fat, increase adiponectin and reduce inflammatory adipokines, fatty acids and glucose in people with Type 2 diabetes. We aimed to measure these effects in people with impaired fasting glucose and/or impaired glucose tolerance.

METHODS

After approximately 3.5 years of exposure to rosiglitazone 8 mg (n = 88) or placebo (n = 102), 190 DREAM trial participants underwent abdominal computed tomography and dual-energy X-ray absorptiometry scans. Visceral and subcutaneous adipose tissue areas, estimated hepatic fat content, total fat and lean mass were calculated and changes in levels of fasting adipokines, free fatty acids, glucose and post-load glucose were assessed.

RESULTS

Compared with the placebo, participants on rosiglitazone had no difference in lean mass, had 4.1 kg more body fat (P < 0.0001) and 31 cm(2) more subcutaneous abdominal adipose tissue area (P = 0.007). Only after adjusting for total fat, participants on rosiglitazone had 23 cm² less visceral adipose tissue area (P = 0.01) and an 0.08-unit higher liver:spleen attenuation ratio (i.e. less hepatic fat; P = 0.02) than those on the placebo. Adiponectin increased by 15.0 μg/ml with rosiglitazone and by 0.4 μg/ml with placebo (P < 0.0001). Rosiglitazone's effect on fat distribution was not independent of changes in adiponectin. Rosiglitazone's effects on fasting (-0.36 mmol/l; P = 0.0004) and 2-h post-load glucose (-1.21 mmol/l; P = 0.0008) were not affected by adjustment for fat distribution or changes in adiponectin or free fatty acids.

CONCLUSIONS

In people with impaired fasting glucose/impaired glucose tolerance, rosiglitazone is associated with relatively less hepatic and visceral fat, increased subcutaneous fat and increased adiponectin levels. These effects do not appear to explain the glucose-lowering effect of rosiglitazone.

Nonalcoholic fatty liver disease after pancreatoduodenectomy is closely associated with postoperative pancreatic exocrine insufficiency

BACKGROUND

In recent years, nonalcoholic fatty liver disease (NAFLD) after pancreatoduodenectomy (PD) has become increasingly problematic. Our aims were to clarify the relationship between NAFLD and postoperative pancreatic exocrine function and to identify the risk factors for NAFLD after PD.

METHODS

Patients who underwent PD (n = 104) were assessed with abdominal unenhanced computed tomography (CT) to determine the fatty liver changes and were given a (13) C-labeled mixed triglyceride breath test to measure pancreatic exocrine function. The percent (13) CO2 cumulative dose at 7 hr (% dose (13) C cum 7 hr) <5% was considered diagnostic for pancreatic exocrine insufficiency (PEI). Relationships between the occurrence of NAFLD and clinical factors including postoperative pancreatic exocrine function were analyzed.

RESULTS

Twenty-six of 104 patients (25%) developed postoperative NAFLD. The postoperative CT attenuation of the liver (R = 0.326, P < 0.001) and the liver-to-spleen attenuation ratio (R = 0.315, P = 0.001) significantly correlated with the postoperative values of % dose (13) C cum 7 hr. Multivariate analysis determined that postoperative PEI was the only independent risk factor for NAFLD (P = 0.025).

CONCLUSIONS

NAFLD frequently occurs postoperatively after PD. NAFLD after PD may be closely associated with postoperative PEI.

Evaluation of Predictive Factors in Patients with Nonalcoholic Fatty Liver Disease after Pancreaticoduodenectomy

Patients who undergo pancreaticoduodenectomy (PD) are at risk of steatosis because resection of the pancreatic head causes pancreatic exocrine and endocrine insufficiency. We investigated the clinicopathological features and the risk factors of nonalcoholic fatty liver disease (NAFLD) after PD. This was a retrospective study of 100 patients who underwent PD between April 2007 and December 2012 in our institution. Preoperative demographic and clinical data, surgical procedures, pathological diagnosis, postoperative course findings, and complication details were collected prospectively. The patients were divided into the following two groups: Group A consisted of 12 patients who developed postoperative NAFLD, and Group B consisted of 88 patients who did not develop postoperative NAFLD. Pancreatic carcinoma and pancreatic texture showed similar findings. Additionally, we found that blood loss significantly correlated with the incidence of nonalcoholic steatohepatitis after PD. In multivariate analysis, only blood loss was identified as the most influential risk factor for NAFLD (hazard ratio, 1.0001; P = 0.016). Blood loss was identified as an independent risk factor for the development of NAFLD after PD. Further prospective studies are needed to identify factors that put patients at risk for NAFLD after PD. Continuing efforts should be made to improve patient outcomes and understand the pathogenesis of postpancreatectomy NASH.

Efficacy of probucol for the treatment of non-alcoholic steatohepatitis with dyslipidemia: An open-label pilot study

AIM

Oxidative stress plays a pivotal role in the transition from simple steatosis to non-alcoholic steatohepatitis (NASH). Probucol is a lipid-lowering agent with strong antioxidant properties, and is reported to be effective for the treatment of NASH in several studies. The aim of the present study was to evaluate the efficacy of probucol for the treatment of NASH with dyslipidemia.

METHODS

Twenty-six patients with biopsy-proven NASH accompanied by dyslipidemia were treated with 500 mg of probucol daily for 48 weeks. Body mass index, visceral fat area, liver function tests, serum lipids, fibrosis markers, ferritin, adiponectin, leptin, urinary 8-hydroxy-2'-deoxyguanosine (U-8OHdG) and elasticity were measured periodically during the study. Follow-up liver biopsy was performed in 18 patients.

RESULTS

Serum levels of aminotransferases, total cholesterol and U-8OHdG significantly decreased (P < 0.01). Levels of hemoglobin A1c (HbA1c), the Homeostasis Model of Assessment - Insulin Resistance index and serum levels of ferritin, type IV collagen 7S and hyaluronic acid significantly decreased (P < 0.05). The serum levels of adiponectin tended to be increased. Liver stiffness significantly decreased from 8.8 ± 6.8 to 6.6 ± 4.0 kPa (P < 0.01). Non-alcoholic fatty liver disease activity scores were significantly improved from 4.2 ± 1.4 to 3.4 ± 1.6 (P < 0.05) and fibrotic stages tended to be improved from 1.6 ± 0.8 to 1.3 ± 1.1, respectively. No adverse effects of this treatment were noted.

CONCLUSION

Probucol improved clinical and histological findings probably through its ability to reduce insulin resistance and oxidative stress. Probucol therapy was safe and effective for Japanese NASH patients with dyslipidemia.

The prevalence and predictors of active brown adipose tissue in Chinese adults

OBJECTIVE

Previous studies have shown that active brown adipose tissue (BAT) is present in adults and may play important roles in the regulation of energy homeostasis. However, nearly every study has been carried out in patients undergoing scanning for cancer surveillance (CS), whose metabolism and BAT activity may not reflect those of healthy individuals. The objective of this study was to investigate the prevalence and predictors of active BAT in Chinese adults, particularly in healthy individuals.

DESIGN

A total of 31,088 consecutive subjects aged ≥18 years who had undergone positron emission tomography/computed tomography (PET/CT) scanning of BAT were evaluated in this study.

METHODS

We measured BAT activity via (18)F-fluorodeoxyglucose PET/CT in subjects who had undergone scanning for either a routine medical checkup (MC) or CS in Shanghai. Then, we investigated the predictors of active BAT, particularly in healthy individuals.

RESULTS

In both groups, the prevalence of BAT was higher in women than in men. Using a multivariate logistic analysis, we found age, sex, BMI, and high thyroid glucose uptake to be significant predictors of BAT activity in the MC group. Similarly, we found age, sex, and BMI to be significant predictors of BAT activity, but not thyroid high glucose uptake, in the CS group.

CONCLUSIONS

In Chinese adults, BAT activity inversely correlates with BMI and thyroid high glucose uptake, which reinforces the central role of brown fat in adult metabolism and provides clues to a potential means for treating the metabolic syndrome.

Quantitative assessment of pancreatic fat by using unenhanced CT: pathologic correlation and clinical implications

PURPOSE

To assess the relationship between computed tomographic (CT) indexes and histologically measured pancreatic fat in surgical specimens and to evaluate patients with impaired glucose metabolism in a clinical setting.

MATERIALS AND METHODS

This retrospective study was institutional review board approved and informed consent was waived. The hospital database was searched for records from November 2008 to April 2009, and 62 patients (42 men and 20 women; mean age, 61.4 years; age range, 21-81 years) who underwent CT within 1 month before pancreatectomy were identified. The histologic pancreatic fat fraction (area ratio of fat to total tissue times 100%) was measured in nontumorous pancreatic tissue. Attenuation was measured in three regions of interest in the pancreas and the spleen on nonenhanced CT images. The difference between pancreatic and splenic attenuation and the pancreas-to-spleen attenuation ratio were calculated. Visceral fat area at the level of the umbilicus was measured on the CT images. Spearman correlation coefficients (ρ) were calculated to examine the correlation between the CT indexes or visceral fat area and the histologic pancreatic fat fraction. A multivariate logistic regression model was used to determine whether CT attenuation indexes and patient age, sex, and visceral fat correlated with impaired glucose metabolism (ie, impaired glucose tolerance, impaired fasting glucose, or presence of diabetes).

RESULTS

The histologic pancreatic fat fraction ranged from 0% to 65.3% and was significantly correlated with the difference between pancreatic and splenic attenuation (ρ = -0.622, P < .01) and the pancreas-to-spleen attenuation ratio (ρ = -0.616, P < .01). The visceral fat area was not correlated with the histologic pancreatic fat fraction (ρ = 0.09, P = .50). The CT attenuation indexes were significant and independent variables predictive of impaired glucose metabolism after adjusting for age, sex, and visceral fat.

CONCLUSION

Pancreatic fat can be quantified by using CT, and CT attenuation indexes that are applied to the quantification of pancreatic fat are significantly associated with clinical assessment of impaired glucose metabolism.

Early left ventricular abnormality/dysfunction in obese children affected by NAFLD

BACKGROUND AND AIMS

Although it is generally accepted that non alcoholic fatty liver disease (NAFLD) is linked to increased risk of cardiovascular disease, the presence of abnormalities in cardiac function among NAFLD children is limited and controversial. Aim of the study was to detect cardiac abnormalities/dysfunction in a paediatric population of NAFLD.

METHODS AND RESULTS

Anthropometric, laboratory, cardiovascular fitness, 24 h blood pressure monitoring and Doppler echocardiography parameters were obtained in 50 untreated children (37 males; mean age 12.2 + 2.5) with biopsy-proven NAFLD. Abnormalities in both cardiac function and geometry could be identified in the whole study population: prevalence of about 35% in left ventricular hypertrophy, 14% of concentric remodelling and 16% of left atrial dilatation. Furthermore children with NAFLD (NAS score <5) showed lower cardiac alterations compared to NASH patients (NAS score >5). After adjusting for age, sex and BMI, a positive correlation was found only between LV mass and NAS score (p < 0.001).

CONCLUSION

Our results suggest that cardiac dysfunction can be detectable early in NAFLD children and this is not linked to cardiovascular and metabolic alteration, other than to liver damage. Although as a preliminary stage, we can speculate a possible direct relationship between liver and heart steatosis, already occurring during childhood.

A 12-week aerobic exercise program without energy restriction improves intrahepatic fat, liver function and atherosclerosis-related factors

SUMMARY

OBJECTIVE

To study the effects of a 12-week continuous aerobic exercise program without energy restriction on intrahepatic fat, indices of liver function (aspartate aminotransferase [AST], alanine aminotransferase [ALT] and γ-glutamyl transpeptidase [γGTP]), plasminogen activator inhibitor-1 (PAI-1) and insulin resistance (HOMA-IR).

METHODS

Subjects were divided into two groups based on the degree of intrahepatic fat accumulation at baseline (high liver fat [HLF]: n = 13; low liver fat [LLF]: n = 14). Participants were instructed to exercise for more than 300 min per week at the lactate threshold. Fat accumulation (intramuscular, intrahepatic, visceral and subcutaneous fat) was evaluated by computed tomography. Blood samples were taken to determine the levels of AST, ALT, PAI-1, glucose and insulin.

RESULTS

Weight, body mass index, body fat, visceral fat and subcutaneous fat decreased significantly in both groups between baseline and post-intervention (P < 0.05), but were not significantly different between the two groups (P > 0.05). Intrahepatic fat, AST, ALT and PAI-1 improved significantly between baseline and post-intervention in the HLF group (P < 0.05; AST, P = 0.052), and improvements were significantly greater than those in the LLF group (P < 0.05). γGTP decreased significantly in the HLF group between baseline and post-intervention (P < 0.05), but was not significantly different between the two groups (P > 0.05). HOMA-IR did not significantly improve between baseline and post-intervention either within or between the two groups (P > 0.05).

CONCLUSION

This study revealed that a 12-week continuous aerobic exercise program without energy restriction might improve intrahepatic fat, liver function and atherosclerosis-related factors.

Serum retinol binding protein 4 is negatively related to beta cell function in Chinese women with non-alcoholic fatty liver disease: a cross-sectional study

BACKGROUND

To observe the relationship between serum retinol binding protein 4(RBP4) and β cell function in Chinese subjects with non-alcoholic fatty liver disease (NAFLD) and without known diabetes.

METHODS

106 patients diagnosed as fatty liver by ultrasonography (M/F: 61/45; aged 47.44 ± 14.16 years) were enrolled in our current cross-sectional study. Subjects with known diabetes, chronic virus hepatitis and excessive alcohol consumption were excluded. Serum RBP4 was detected by ELISA and validated by quantitative Western blotting. β cell function were assessed by HOMA in all subjects and by hyperglycemic clamp in 17 normal glucose tolerance subjects (M = 6, F = 11).

RESULTS

The levels of serum RBP4 in men were higher than that in women (55.96 ± 11.14 vs 45.87 ± 10.31 μg/ml, p < 0.001). Pearson's correlation analysis demonstrated that in women, serum RBP4 levels were significantly associated with fasting blood glucose (FBG), HOMA-β, and increment of first phase insulin secretion (1PH), but not associated with age, BMI, waist circumference, WHR, systolic (SBP) and diastolic blood pressure (DBP), TC, TG, HDL-c, LDL-c, 2 h blood glucose, HOMA-IR, ALT, AST, γ-GT, hepatic fat content (HFC), and insulin sensitivity index (ISI). However, in men, serum RBP4 levels were significantly associated with HDL-c, ALT, AST, but not associated with any other parameters as mentioned above. A stepwise multiple linear regression analysis demonstrated that in women, HOMA-IR and RBP4 were significantly associated with HOMA-β, while in men, HOMA-IR and BMI were significantly variables associated with HOMA-β.

CONCLUSIONS

Serum RBP4, secreted mainly by liver and adipose tissue, may involve in the pathogenesis of β cell dysfunction in Chinese women patients with NAFLD.

Polycystic ovary syndrome and nonalcoholic fatty liver in obese adolescents: association with metabolic risk profile

OBJECTIVE

To investigate the relationship between liver fat and in vivo insulin sensitivity, body composition, abdominal adiposity, and lipid metabolism in obese adolescent girls with polycystic ovary syndrome (PCOS).

DESIGN

Cross-sectional case-control study.

SETTING

Research center.

PATIENT(S)

Thirty Tanner stage V obese girls with PCOS.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Liver fat, abdominal adiposity, in vivo insulin-stimulated glucose disposal, whole-body lipolysis, fat oxidation, lipoprotein particle size and concentration, and liver enzymes (alanine aminotransferase and aspartate aminotransferase). Fatty liver index <1 is indicative of fatty liver.

RESULT(S)

Fatty liver was present in 6.7% of the individuals (6.7%). Levels of alanine aminotransferase and aspartate aminotransferase were not different between those with fatty liver vs. without. Fatty liver index was associated with age (r = -0.53), body mass index (r = -0.41), total (r = -0.43) and subcutaneous (r = -0.41) abdominal adiposity, insulin-stimulated glucose disposal (r = 0.36), and small, medium small, and very small low-density lipoprotein concentrations (r ≥ -0.43). In a multiple regression analysis, age, total T, race, and insulin-stimulated glucose disposal explained 43% of the variance (R(2) = 0.43) in fatty liver index, with age (R(2) = 0.28) and total T (R(2) = 0.11) being independent contributors.

CONCLUSION(S)

Liver fat is associated with increasing age, even in the narrow adolescent age range, increasing abdominal adiposity, worsening insulin sensitivity, and dyslipoproteinemia in obese adolescent girls with PCOS. Targeting these abnormalities early in the course of PCOS may halt future nonalcoholic fatty liver disease in adulthood.

Ectopic fat: the true culprit linking obesity and cardiovascular disease?

Obesity is a major risk factor for cardiovascular disease and its complications. However, not all fat depots share the same characteristics. Recent studies have found that ectopic rather than subcutaneous fat accumulation is associated with increased cardiometabolic risk. However, ectopic fat accumulation can be seen initially as a protective mechanism against lipotoxicity. Subsequently the adipose tissue becomes dysfunctional, thus inducing systemic metabolic alterations (through release of cytokines) or specific organ dysfunctions. The purpose of this review is to summarise the current available data on the impact of excess adiposity vs ectopic fat in the development of cardio-metabolic diseases.

Hepatic steatosis estimated microscopically versus digital image analysis

BACKGROUND & AIMS

Evaluate in liver biopsies: (i) interobserver agreement of estimates of fat proportionate area (eFPA) and steatosis grading, (ii) the relationship between steatosis grades and measured fat proportionate area (mFPA, digital image analysis), (iii) the accuracy of eFPA, (iv) to present images to aid standardization and accuracy of eFPA.

METHODS

Twenty-one liver biopsies were selected from the Royal Free Hospital (RFH) histopathology archive to represent the full range of histopathological steatosis severity. As many non-overlapping fields of parenchyma as possible were photographed at ×20 objective magnification from the biopsies (n = 651). A total of 15 sample images were selected to represent the range of steatosis seen. Twelve hepatopathologists from 11 sites worldwide independently evaluated the sample images for steatosis grade [normal (none)/mild/moderate/severe], and eFPA (% area of liver parenchyma occupied by fat).

RESULTS

The hepatopathologists had good linear correlation between eFPA and mFPA for sample images (r = 0.924, P < .001) and excellent concordance (kappa = 0.91, P < 0.001). Interobserver concordance of steatosis grade showed 'substantial agreement' (kappa = 0.64). There was significant difference between eFPA and mFPA in the sample images for mild, moderate and severe steatosis (P = 0.024, P < 0.001, P < 0.001 respectively): the observers consistently over-estimated the eFPA.

CONCLUSION

Hepatopathologists showed 'excellent' interobserver agreement in eFPA and 'substantial' agreement in assigning steatosis grade (precision was high). However, compared with mFPA, eFPA was inaccurate. eFPA systematically exceeds mFPA; generally the overestimation increases with severity of steatosis. Considering that non-invasive technologies for estimating liver fat utilize histopathology as reference, such assessments would benefit from quantitative validation of visually estimated microscopic liver fat percentages.

Measuring visceral and hepatic fat in clinical practice and clinical research

OBJECTIVE

To review how visceral and hepatic fat are measured in clinical practice and clinical research.

METHODS

We examine different methods employed to assess visceral and hepatic fat in the literature.

RESULTS

Fat in the human body is located in 2 main compartments: subcutaneous and visceral, which also includes liver fat. Visceral and liver fats are associated with the metabolic complications of obesity like hypertension, diabetes, and atherosclerosis. Therefore, there is a need to detect those fats early in life before the development of cardiometabolic syndrome (CMS). Many modalities have been proposed to measure visceral and liver fat. Indirect measurements can be done through waist circumference (WC), dual-energy X-ray absorptiometry (DEXA), ultrasound, and bioelectric impedance, whereas direct methods include computed tomography (CT) and magnetic resonance imaging (MRI). An ideal measurement method should be noninvasive, reliable, suitable for all body sizes, widely available, cost and time effective, show low variability, and have no or limited radiation exposure.

CONCLUSION

Measuring visceral and liver fat is not a straightforward procedure in clinical practice or research; several variables may affect measure accuracy and validity.