Nonalcoholic fatty liver disease in children

Metabolic Abnormalities in a Cohort of Overweight and Obese Children in an Urban Setting of Sri Lanka

Childhood obesity-related metabolic derangements are increasing among South Asian populations. Most of these changes persist to adulthood. This study aims to describe the distribution of metabolic abnormalities among 7- to 17-year-old overweight and obese children in the Gampaha District of Sri Lanka. Overweight children (age- and gender-adapted BMI>+1SD, WHO standards) were selected from a community survey carried out in the Negombo Education Zone of Gampaha District. After a 12-hour overnight fast, blood was drawn, and blood glucose (FBG), lipid profile, insulin, and liver transaminases were measured. Two hours after a glucose load, blood was drawn for random blood glucose (RBG) and insulin. Metabolic syndrome (MetS) was diagnosed using modified IDF criteria for children. Anthropometry, fat mass (FM), and blood pressure were measured. Hepatic fat pattern was assessed ultrasonically. The data of 403 children (210 boys) were analysed. Of the study population, 16.4% were overweight (BMI for age +1 to +2SD), 72% were obese (BMI for age >+2 to +3SD), and 11.6% were severely obese (BMI for age >+3SD). Insulin resistance was seen in 46.8%, and prevalence increased with age. Mean postprandial insulin ranged from 368 to 625 pmol/L and was elevated in 35%. Dysglycaemia was seen among 20.8%. MetS was present in 19.8%, and 84% had at least one metabolic abnormality. Different degrees of hepatic steatosis were observed in 32.5%, and elevated ALT/AST ratio was seen in 58% of the population. Overweight and obesity during childhood were associated with multiple metabolic abnormalities including MetS, and they occur from a young age. It is important to screen children for overweight/obesity early in life and intervene to prevent them from developing metabolic complications.

Relationship between Neck Circumference and Non-Alcoholic Fatty Liver Disease in Childhood Obesity

OBJECTIVE

The aim of this study was to establish the association between anthropometric parameters and non-alcoholic fatty liver disease (NAFLD) and to determine the most reliable measurement as a parameter in predicting NAFLD.

METHODS

Two-hundred fifty-three obese children of ages 10 to 18 years were enrolled in this study. Anthropometric data and metabolic parameters such as fasting blood glucose, insulin and lipid levels, were measured. Liver function tests were assessed. NAFLD was determined by ultrasound.

RESULTS

Most metabolic parameters and anthropometric indices were significantly higher in children with NAFLD. A univariate logistic regression analysis was performed, taking NAFLD status as the dependent variable and anthropometric parameters as the independent variables. NAFLD was affected significantly by the anthropometric values. The multiple logistic regression analysis showed that neck circumference (NC) was the only parameter which determined the risk in both genders. Each 1 cm increase in the NC increased the risk of NAFLD 1.544-fold (p<0.001, 95% confidence interval (CI): 1.357-2.214) in the boys and 1.733-fold (p=0.001, 95% CI: 1.185-2.012) in the girls. Receiver operating characteristic analysis was performed to compare the reliability of anthropometric measurements. NC was observed to be a better indicator.

CONCLUSION

Measurement of the NC was shown to be associated with NAFLD in children. We suggest the use of NC as a novel, simple, practical, and reliable anthropometric index in predicting children at risk for NAFLD.

Severe childhood obesity: an under-recognised and growing health problem

Childhood obesity is a serious and urgent public health problem. In the last 10 years, there has been a concerted effort in the USA and globally to develop and implement educational, medical and public health interventions designed to attenuate its growth. The success of these efforts was probably responsible for the plateau in the prevalence rate of childhood obesity noted in the last two years. While the attenuation of the overall prevalence of childhood obesity is promising, data from the same cohort reveal a concerning upward trend in the number of children with severe obesity. The consequences of severe childhood obesity can be devastating. When compared to their moderately obese peers, children with severe obesity are at greater risk for adult obesity, early atherosclerosis, hypertension, type 2 diabetes, metabolic syndrome, fatty liver disease and premature death. The determinants for severe obesity include the same lifestyle, environmental, familial and societal risk factors reported for overweight or obesity. While all these risk factors must be screened for, genetic influences are distinct considerations that may have greater bearing especially with early-onset obesity. Treatments for severe childhood obesity include lifestyle intervention, specialised low-calorie diets and bariatric surgery. Outcomes of these treatments vary, with bariatric surgery clearly the most successful of the three for both short-term and long-term weight loss. Severe obesity in children and adolescents remains a challenging health condition. The enormous medical, emotional and financial burden these children and their families endure signals an urgent need to further investigate and standardise treatment modalities and improve outcomes.

Association of ALT and the metabolic syndrome among Mexican children

Nonalcoholic fatty liver disease (NAFLD) is emerging as a component of the metabolic syndrome (MetS); Hispanics being particularly predisposed. Alanine aminotransferase (ALT) is considered a marker of NAFLD. The aim of this study was to determine the prevalence and associations between ALT elevations and MetS in normal-weight, overweight and obese Mexican children and adolescents, since data in Mexico is scarce. Body mass index (BMI), waist circumference (WC), percentage body fat, blood pressure, glucose, lipid profiles, ALT and aspartate aminotransferase (AST) were measured in 236, 6-12yo normal-weight, overweight and obese Mexicans from eight public schools. The results showed that elevated ALT (>40 IU/L) was found in 17.7% of the obese and overweight population, with no gender difference. The prevalence of elevated ALT increased linearly across BMI categories (p = 0.001), from 0.0% for the normal-weight group (95%CI 0.0-€“8.0) to 22.4% for the obese one (95%CI 16.2-€“30.2). AST/ALT ratio <1 also increased linearly, as did the prevalence of MetS (p = 0.001), from 0.0% for the normal-weight group to 40.3% for the obese one. The prevalence of MetS was strongly associated with elevated ALT (p = 0.002), 50% in the elevated ALT group (95%CI 34.1-€“65.9) and 24.1% in the normal ALT one (95%CI 18.1-€“31.3). There was also a strong association between MetS and an AST/ALT ratio <1. WC was the best predictor of elevated ALT (AOR = 7.13). Pearson correlation showed that MetS components were significantly correlated with elevated ALT. Therefore elevated ALT levels were highly prevalent and strongly associated with MetS in Mexican children, it should be screened in overweight and obese children.

The effect of a low fructose and low glycemic index/load (FRAGILE) dietary intervention on indices of liver function, cardiometabolic risk factors, and body composition in children and adolescents with nonalcoholic fatty liver disease (NAFLD)

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common liver disease in obese children. Diets high in added fructose (high fructose corn syrup; HFCS) and glycemic index (GI)/glycemic load (GL) are associated with increased risk of NAFLD. Lifestyle modification is the main treatment, but no guidelines regarding specific dietary interventions for childhood NAFLD exist. We hypothesized that reductions in dietary fructose (total, free, and HFCS)/GI/GL over 6 months would result in improvements in body composition and markers of liver dysfunction and cardiometabolic risk in childhood NAFLD.

METHODS

Children and adolescents with NAFLD (n = 12) and healthy controls (n = 14) 7-18 years were studied at baseline and 3 and 6 months post-dietary intervention. Plasma markers of liver dysfunction (ALT, AST, γGT), cardiometabolic risk (TG, total cholesterol, LDL-HDL cholesterol, Apo-B100, Apo-B48, Apo-CIII, insulin, homeostasis model of assessment of insulin resistance [HOMA-IR]), inflammation (TNF-α, IL-6, IL-10), anthropometric, and blood pressure (BP) were studied using validated methodologies.

RESULTS

Significant reductions in systolic BP (SBP), percentage body fat (BF), and plasma concentrations of ALT (P = .04), Apo-B100 (P < .001), and HOMA-IR were observed in children with NAFLD at 3 and 6 months (P < .05). Dietary reductions in total/free fructose/HFCS and GL were related to reductions in SBP (P = .01), ALT (P = .004), HOMA-IR (P = .03), and percentage BF in children with NAFLD. Reductions in dietary GI were associated with reduced plasma Apo-B100 (P = .02) in both groups. With the exception of Apo-B100, no changes in laboratory variables were observed in the control group.

CONCLUSION

Modest reductions in fructose (total/free, HFCS) and GI/GL intake result in improvements of plasma markers of liver dysfunction and cardiometabolic risk in childhood NAFLD.

A meal high in saturated fat evokes postprandial dyslipemia, hyperinsulinemia, and altered lipoprotein expression in obese children with and without nonalcoholic fatty liver disease

BACKGROUND

Hyperinsulinemia and altered lipid and lipoprotein metabolism induced by fast-food diets may contribute to nonalcoholic fatty liver disease (NAFLD). We hypothesized that a high saturated fat (SFA) meal would evoke prolonged postprandial lipemia and hyperinsulinemia, increased inflammation, and altered lipoprotein expression in obese children with NAFLD when compared with healthy children.

METHODS

We prospectively studied 31 children (NAFLD, 13.1 ± 2.6 years, n = 11; age-matched obese, 14.3 ± 1.7 years, n = 9; lean, 13.6 ± 2.6 years, n = 11) following consumption of a high SFA (18.8%) meal. Prior to and at 1, 3, and 6 hours after meal consumption, blood was collected for analysis of alanine aminotransferase (ALT); aspartate aminotransferase (AST); γ-glutamyltransferase; leptin; C-reactive protein; (fasting) insulin; glucose; triglycerides (TGs); total, high-density lipoprotein, and low-density lipoprotein cholesterol; adiponectin; nonesterified fatty acids (NEFAs); inflammatory markers (TNF-α, IL-6, IL-10); apolipoproteins-B48, B100, and CIII; and fatty acid (FA) composition of TG fractions.

RESULTS

Children with NAFLD had significantly higher fasting levels of ALT (87 ± 54 U/L), AST (52 ± 33.5 U/L), and apolipoprotein-CIII (20.6 ± 11.3 mg/dL) with postprandial hyperinsulinemia (iAUC insulin: 225 ± 207 [NAFLD] vs 113 ± 73 [obese] vs 47 ± 19.9 [lean] mU/L-h; P < .001); suppression of NEFA (iAUC-NEFA: 1.7 ± 0.9 [NAFLD] vs 0.6 ± 0.3 [obese] vs 1 ± 0.7 [lean] mEq/L-h); and prolonged elevations in apolipoprotein-B48 3-6 hours after meal consumption when compared with obese and lean controls (P < .05).

CONCLUSION

A meal high in saturated fat evokes postprandial dyslipemia, hyperinsulinemia, and altered lipoprotein expression in obese children with and without NAFLD.

Anthropometric measures of visceral and subcutaneous fat are important in the determination of metabolic dysregulation in boys and girls at risk for nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is increasing at alarming rates in obese children. The study aim was to describe body composition/somatotype and its interrelationships to biomarkers of liver disease, insulin resistance, and lipid and cytokine expression in youth with NAFLD.

METHODS

Somatotype and body composition of children (7-18 years) diagnosed with NAFLD (n= 18) were compared with obese (n = 11) and lean children (n = 17). Anthropometric variables assessed included weight, height, body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHTR), and multiple skinfold thicknesses. Fat mass (FM) and somatotype analysis were measured using validated methodologies. Fasting liver biochemistries (aspartate aminotransferase [AST], alanine aminotransferase [ALT], γ-glutamyltransferase [GGT]), insulin, glucose, leptin, C-reactive protein (CRP), tumor necrosis factor-α, interleukin (IL) factors 6/10, apolipoproteins B-100/B-48 and C-III, triglycerides, and high-density lipoprotein (HDL)/low-density lipoprotein (LDL) cholesterol were measured. Insulin resistance was assessed by the homeostasis model of insulin resistance (HOMA-IR).

RESULTS

BMI z score, WC, FM, and somatotype did not differ between NAFLD and obese groups; however, lean children were lighter/leaner across all anthropometric measures (P < .001). Children with NAFLD had a higher sum-of-trunk to sum-of-extremity ratio (1.6 ± 0.4) than did obese (1.3 ± 0.2) and lean (1.1 ± 0.5) children (P < .001). Markers of central visceral (WC/WHTR) and subcutaneous fat (subscapular, abdominal, suprailiac skinfolds) were associated with elevated plasma concentrations of insulin, HOMA-IR, ALT, GGT, and AST and lower HDL cholesterol and IL-10 (P < .001).

CONCLUSION

Comprehensive assessment of body composition, including measurement of surrogate markers of subcutaneous and visceral fat, provides information regarding metabolic dysregulation and liver disease risk in obese children with NAFLD.

Non-alcoholic fatty liver disease impairs hippocampal-dependent memory in male rats

Non-alcoholic fatty liver disease (NAFLD) is a disorder observed in children and adults characterized by an accumulation of liver fat (>5% wet weight) in the absence of excessive alcohol intake. NAFLD affects 10 to 30% of the American population and is the most common cause of liver disease in the United States. NAFLD leads to serious disturbances in cardiovascular and hormonal function; however, possible effects on brain function have been overlooked. The aims of the present study were to test whether diet-induced NAFLD impairs hippocampal-dependent memory and to determine whether any observed deficits are associated with changes in hippocampal insulin signaling or concentrations of brain-derived neurotrophic factor (BDNF) and insulin-like growth factor-1 (IGF-1). Post-weanling male Sprague-Dawley rats were fed a high fructose (60% of calories) or control diet for 12 weeks and then trained and tested in a spatial water maze. NAFLD was confirmed with postmortem measures of liver mass and liver lipid concentrations. NAFLD did not affect acquisition of the spatial water maze, but did impair retention tested 48 h later. Specifically, both groups demonstrated similar decreases in latency to swim to the escape platform over training trials, but on the memory test NAFLD rats took longer to reach the platform and made fewer visits to the platform location than control diet rats. There were no differences between the groups in terms of insulin-stimulated phosphorylation of insulin receptor β subunit (IR-β) and protein kinase B (PKB/AKT) in hippocampal slices or hippocampal BDNF or IGF-1 concentrations. Thus, these data indicate that NAFLD impairs hippocampal-dependent memory function and that the deficit does not appear attributable to alterations in hippocampal insulin signaling or hippocampal BDNF or IGF-1 concentrations.

Short-term outcomes of community-based adolescent weight management: The Loozit® Study

BACKGROUND

The Loozit(®) Study is a randomised controlled trial investigating extended support in a 24 month community-based weight management program for overweight to moderately obese, but otherwise healthy, 13 to 16 year olds.

METHODS

This pre-post study examines the two month outcomes of the initial Loozit(®) group intervention received by both study arms. Adolescents (n = 151; 48% male) and their parents separately attended seven weekly group sessions focused on lifestyle modification. At baseline and two months, adolescents' anthropometry, blood pressure, and fasted blood sample were assessed. Primary outcomes were two month changes in body mass index (BMI) z-score and waist-to-height-ratio (WHtR). Secondary outcomes included changes in metabolic profile, self-reported dietary intake/patterns, physical and sedentary activities, psychological characteristics and social status. Changes in outcome measures were assessed using paired samples t-tests for continuous variables or McNemar's test for dichotomous categorical variables.

RESULTS

Of the 151 adolescents who enrolled, 130 (86%) completed the two month program. Among these 130 adolescents (47% male), there was a statistically significant (P < 0.01) reduction in mean [95% CI] BMI (0.27 kg/m2 [0.41, 0.13]), BMI z-score (0.05 [0.06, 0.03]), WHtR (0.02 [0.03, 0.01]), total cholesterol (0.14 mmol/L [0.24, 0.05]) and low-density lipoprotein cholesterol (0.12 mmol/L [0.21, 0.04]). There were improvements in all psychological measures, the majority of the dietary intake measures, and some physical activities (P < 0.05). Time spent watching TV and participating in non-screen sedentary activities decreased (P < 0.05).

CONCLUSIONS

The Loozit(®) program may be a promising option for stabilizing overweight and improving various metabolic factors, psychological functioning and lifestyle behaviors in overweight adolescents in a community setting.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials RegistryACTRNO12606000175572.

Safety of blind percutaneous liver biopsy in obese children: a retrospective analysis

GOAL

To determine the safety and adequacy of blind percutaneous liver biopsy (PLB) in obese children.

BACKGROUND

PLB is an important diagnostic tool that, while invasive, enjoys a relatively low major complication rate. An ever increasing reason for pediatric liver biopsy is nonalcoholic fatty liver disease associated with obesity. There is a lack of data assessing the safety of liver biopsy in obese compared to nonobese children.

STUDY

A retrospective study of all children over 5 years of age having PLB was conducted. Data collected included age, gender, weight, height, BMI, reason for biopsy, number of passes, biopsy length, number of portal triads per biopsy, and complication rates.

RESULTS

A total of 107 biopsies were reviewed. All biopsies were successful. Overall, major complications occurred in 1.3% and minor complications in 8.4%; there were no deaths. Comparison revealed no difference for number of passes (1.5±0.7 vs. 1.7±0.7), biopsy length (2.0±1.3 cm vs. 1.5±1.1 cm), number of portal tracts per biopsy (9.8±5.8 vs. 9.9±3.4), or complication rates (major: 0% vs. 1.3%; minor: 10.0% vs. 7.8%) between obese and nonobese children.

CONCLUSION

Blind PLB can be safely carried out in obese children with no increase in complication rate compared with nonobese children. Similarly, there is no difference in number of passes, biopsy size, portal triads per biopsy, or biopsy success for obese children.

Endotoxin and plasminogen activator inhibitor-1 serum levels associated with nonalcoholic steatohepatitis in children

OBJECTIVES

Recent evidence supports a role for endotoxemia in the progression from nonalcoholic fatty liver disease (NAFLD) to nonalcoholic steatohepatitis (NASH). We investigated the association between serum levels of endotoxin, proinflammatory molecules, and histology in children with NAFLD.

PATIENTS AND METHODS

A total of 40 children, mean age of 11.9 +/- 2.8 years (27 male and 13 female), with biopsy-proven NAFLD were consecutively enrolled. Anthropometrics, blood pressure, and parameters of the metabolic syndrome were collected. Serum levels of endotoxin, plasminogen activator inhibitor-1 (PAI-1), tumor necrosis factor (TNF)-alpha, and interleukin (IL)-6 were measured by an enzyme-linked immunosorbent assay and compared with circulating levels of the same soluble factors in 9 age- and sex-matched normal weight controls (age 11.4 +/- 1.7 years; 6 boys and 3 girls).

RESULTS

Children with NAFLD had markedly higher serum concentrations of endotoxin (P < 0.01), PAI-1 (P < 0.001), TNF-alpha, and IL-6 (P < 0.05) than control subjects. Endotoxin (P = 0.002), PAI-1, (P < 0.001), IL-6 (P = 0.002), TNF-alpha (P = 0.02), and body mass index (P = 0.03) were significantly associated with a NAFLD activity score >or=5 at the univariate analysis. At the stepwise regression analysis, endotoxin (P < 0.0001) and PAI-1 (P = 0.009) were the most significant predictors for NAFLD activity score.

CONCLUSIONS

Our findings demonstrate that, apart from TNF-alpha and IL-6, endotoxin and PAI-1 may represent good markers of NASH. They also reinforce the hypothesis that elevated levels of endotoxin may contribute to the progression from NAFLD to NASH.

Association of the components of the metabolic syndrome with non-alcoholic fatty liver disease among normal-weight, overweight and obese children and adolescents

OBJECTIVES

This study aimed to determine the prevalence of the metabolic syndrome, abnormalities of liver enzymes and sonographic fatty liver, as well as the inter-related associations in normal weight, overweight and obese children and adolescents.

METHODS

This cross-sectional study was conducted among a sample of 1107 students (56.1% girls), aged 6-18 years in Isfahan, Iran. In addition to physical examination, fasting blood glucose, serum lipid profile and liver enzymes were determined. Liver sonography was performed among 931 participants. These variables were compared among participants with different body mass index (BMI) categories.

RESULTS

From lower to higher BMI category, alanine aminotransferase (ALT), total cholesterol, LDL-cholesterol, triglycerides and systolic blood pressure increased, and HDL-cholesterol decreased significantly. Elevated ALT, aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were documented in respectively 4.1%, 6.6% and 9.8% of normal weight group. The corresponding figure was 9.5%, 9.8% and 9.1% in overweight group, and 16.9%, 14.9% and 10.8% in obese group, respectively. In all BMI categories, ALT increased significantly by increasing the number of the components of the metabolic syndrome. Odds ratio for elevated liver enzymes and sonographic fatty liver increased significantly with higher number of the components of the metabolic syndrome and higher BMI categories before and after adjustment for age.

CONCLUSIONS

Because of the interrelationship of biochemical and sonographic indexes of fatty liver with the components of the metabolic syndrome, and with increase in their number, it is suggested to determine the clinical impact of such association in future longitudinal studies.

Can the insulin sensitivity index (ISI) in association with insulin-like growth factor binding protein-1 identify insulin resistance early in overweight children?

Association between insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD) has been reported. This prompted us to evaluate the power of the insulin sensitivity index (ISI) in association with IGFBP-1 to identify IR early in obese children/adolescents. OGTT was performed in 34 obese/overweight children/adolescents. Glucose, insulin and IGFBP-1 were measured in serum samples and ISI was calculated. Considering the presence of three or more risk factors for IR as a criterion for IR, ISI < 4.6 showed 87.5% sensitivity and 94.5% specificity in diagnosing IR. IGFBP-1 was lower in the group with ISI < 4.6 (p < 0.01). In this group, three patients had higher than expected IGFBP-1, suggesting hepatic IR, while three patients with ISI > 4.6 showed very low IGFBP-1 levels.

CONCLUSION

ISI < 4.6 is a good indicator of early peripheral IR and, associated with IGFBP-1, can identify increased risk of hepatic IR. Low IGFBP-1 levels among non-IR children may indicate increased portal insulin levels.

Prevalence of non-alcoholic fatty liver disease in children and relationship to metabolic syndrome, insulin resistance, and waist circumference

OBJECTIVES

To investigate the prevalence of non-alcoholic fatty liver disease (NAFLD) in children and its relationship to metabolic syndrome, insulin resistance, and waist circumference (WC).

METHODS

This was a population-based cross-sectional, case-control study. Cases were selected among students of a primary and junior high school, respectively, and age- and sex-matched control subjects were selected randomly (ratio of cases to control subject was 37:113).

RESULTS

Of the 846 students, aged between 6 and 15 years, enrolled in the study and screened by ultrasonography, 37 children were diagnosed as having NAFLD (score >/= 1). There was a significant sex difference in the prevalence of NAFLD(P = 0.003). The trend test revealed a strong dose-response relationship (P < 0.001) between pediatric NAFLD and the number of the proposed components of pediatric metabolic syndrome in Japan (MetS-JC), such as a clustering of the components of MetS-JC. Additionally, the linear trend of the odds ratios (ORs) with increasing percentile of the homeostasis model assessment-insulin resistance (HOMA-IR) was statistically significant (P < 0.001). However, when WC was added to the logistic model, the ORs were no longer significant, whereas WC turned out to be an independent risk factor for NAFLD regardless of the HOMA-IR index.

CONCLUSION

The prevalence of NAFLD in children and adolescents is closely related to metabolic syndrome, insulin resistance, and WC.

MRI in identifying hepatic steatosis in obese children and relation to ultrasonography and metabolic findings

OBJECTIVES

The aim of this study was to identify nonalcoholic fatty liver in obese children by magnetic resonance imaging (MRI) and to compare the findings with the data from ultrasonography and from clinical and laboratory testing.

PATIENTS AND METHODS

Sixty obese children, 6 to 14 years old, underwent hepatic MRI and abdominal ultrasonography. Biochemistry determinations included serum aminotransferases, lipid profile, glucose, and insulin. Anthropometry included body mass index, total and trunk fat, and fat-free mass obtained by dual-energy radiographic absorptiometry. Hepatic steatosis, judged as hepatic fat fraction by MRI, was >or=9%.

RESULTS

By MRI, 14 (23%) children had hepatic steatosis; of those, 5 had a fat fraction of 9% to 18%, and 9 had a fat fraction >18%. At univariate analysis, fat fraction was positively associated with being male, serum alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyltransferase, body mass index z score, insulin, systolic pressure, and total and trunk fat mass. Hepatic steatosis was independently associated with alanine aminotransferase (P < 0.01). Overall, liver echogenicity on ultrasonography correlated well with fat fraction by MRI (correlation coefficient 0.527, P < 0.0001). Among the 27 children with increased liver echogenicity, 13 (48%) had hepatic fat fraction >or=9%, and 89% of children with echogenicity graded 2 or 3 had fat fraction >18%. All of the children (n = 9) with fat fraction >18% had increased liver echogenicity, and in 8 of them it was graded 2 or 3, but the MRI fat fraction ranged greatly (28%-45%).

CONCLUSIONS

In obese children, nonalcoholic hepatic steatosis may be associated with the metabolic syndrome. Ultrasonography may be valuable in identifying high hepatic fat accumulation, but its ability to identify lower fat accumulation in the liver is scanty compared with MRI.

Bicyclol, a synthetic dibenzocyclooctadiene derivative, decreases hepatic lipids but increases serum triglyceride level in normal and hypercholesterolaemic mice

Bicyclol is used for the treatment of chronic hepatitis B in China. In this study, the effects of bicyclol (100 or 300 mg kg(-1), p.o.) on serum and liver lipid contents were investigated in both normal and experimentally induced hypercholesterolaemic mice. Hypercholesterolaemia was induced by either oral administration of cholesterol/bile salt or feeding a diet containing lard/cholesterol. Daily administration of bicyclol for 7 days dose-dependently increased the serum triglyceride level (29-80%) but slightly decreased the hepatic total cholesterol level (12-17%) in normal mice. Co-administration of bicyclol with cholesterol/bile salt decreased the hepatic triglyceride and total cholesterol levels (7-15% and 25-31%, respectively), when compared with the drug-untreated and cholesterol/bile salt-treated group. Bicyclol treatment for 7 days decreased hepatic triglyceride (5-76%) and total cholesterol (5-48%) levels in mice fed with high-fat/cholesterol diet. In contrast, bicyclol treatment increased the serum triglyceride level (18-77%) in mice treated with cholesterol/bile salt or fed with high-fat/cholesterol diet. Bicyclol treatment also caused an increase in hepatic index of normal and hypercholesterolaemic mice (3-32%). The results indicate that bicyclol treatment can invariably decrease hepatic lipid levels and increase serum triglyceride levels in normal and hypercholesterolaemic mice.

Schisandrin B from Schisandra chinensis reduces hepatic lipid contents in hypercholesterolaemic mice

The effects of schisandrin B (Sch B) on liver and serum lipid contents were investigated in mice with experimentally-induced hypercholesterolaemia. Hypercholesterolaemia was induced either by oral administration of a cholesterol/bile salts mixture (2/0.5 g kg(-1)) for four days or by feeding a high fat/cholesterol/bile salts (10/1/0.3%, w/w) diet for seven days. Daily co-administration of Sch B (50-200 mg kg(-1), i.g.) for four or six days, respectively, decreased hepatic total cholesterol (TC) and triglyceride (TG) levels (by up to 50% and 52%, respectively) in hypercholesterolaemic mice. Sch B treatment also increased hepatic indices (14-84%) in hypercholesterolaemic mice. The results indicated that Sch B treatment could decrease hepatic TC and TG levels, and increase liver weight, in mouse models of hypercholesterolaemia. Fenofibrate treatment (100 mg kg(-1)) produced effects similar to those of Sch B on the hepatic index and lipid levels of hypercholesterolaemic mice.

Nonalcoholic fatty liver disease and carotid atherosclerosis in children

Nonalcoholic fatty liver disease (NAFLD) is closely associated with several metabolic syndrome features, including obesity, dyslipidemia, insulin resistance, and increased cardiovascular risk. The present study was undertaken to assess whether NAFLD in children is associated with increased carotid artery intima-media thickness (IMT), a marker of early-generalized atherosclerosis. We analyzed carotid IMT along with serum triglycerides, total, low-density lipoprotein and high-density lipoprotein cholesterol, glucose, insulin, insulin resistance index (as homeostasis model assessment of insulin resistance), aminotransferases, leptin, and adiponectin in 29 obese children with NAFLD, 33 obese children without liver involvement, and 30 control children. The diagnosis and severity of NAFLD was based on ultrasound scan, after exclusion of infectious and metabolic disorders. Obese children with NAFLD had significantly increased carotid IMT [mean 0.58 (95% confidence intervals 0.54-0.62 mm)] than obese children without liver involvement [0.49 (0.46-0.52) mm; p = 0.001] and control children [0.40 (0.36-0.43) mm; p < 0.0005]. In a stepwise multiple regression model, after adjusting for age, gender, Tanner stage, and cardiovascular risk factors, the severity of fatty liver was significantly associated with maximum IMT (b = 0.08; p < 0.0005). Our results suggest that NAFLD is strongly associated with carotid atherosclerosis even in childhood.

Pathology of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are gaining increasing recognition as components of the emerging epidemic of obesity in North America and in other parts of the world. These entities are considered the hepatic manifestations of the insulin resistance syndrome and represent the spectra of fatty liver disease associated with it. All features of metabolic syndrome are associated with NAFLD/NASH, including obesity, type 2 diabetes, arterial hypertension, and hyperlipidemia in the form of elevated triglyceride levels. NAFLD/NASH can progress to liver cirrhosis and has been reported as a cause of hepatocellular carcinoma. In this review, the histopathologic features of NAFLD/NASH and differential diagnostic considerations are discussed. In addition, grading and staging schema proposed and currently in use are reviewed. Finally, other aspects for consideration by practicing pathologists, such as sampling issues, histopathologic findings after therapeutic interventions, and recurrence after liver transplantation, are addressed.

Microarray analyses and molecular profiling of steatosis induction in immortalized human hepatocytes

Hepatic steatosis is an important risk factor for the development of inflammation, fibrosis and impaired liver regeneration. The factors regulating lipid accumulation and driving hepatic steatosis toward inflammation, fibrosis and impaired regeneration are largely unknown. The aim of this study was to identify major alterations in gene expression occurring in steatotic hepatocytes, and to analyze how these changes impact cellular processes associated with steatosis. Microarray gene chips and RT-PCR were performed to analyze changes in gene expression induced in fatty human immortalized hepatocytes after treatment with 50 muM oleic acid for 7 days. Lipid metabolism and triglyceride accumulation in these cells was examined by Oil-Red-O staining, thin-layer chromatography (TLC) and immunofluorescence. Caspase 3 activity, BrdU incorporation and trypan blue exclusion were used to study apoptosis, proliferation and cell viability. Finally, quantitative analysis of signalling induced by insulin was performed by Western blot. Characterization of steatosis in three hepatocyte-derived cell lines indicated that the immortalized human hepatocytes (IHH) line was the most appropriate cell line for this study. Gene expression analysis showed significant alterations in the transcription of two major classes of genes involved either in cholesterol and fatty acid biosynthesis, as well as lipid export, or in apoptosis and cell proliferation. Such changes were functionally relevant, since TLC indicated that synthesis and accumulation of triglycerides were increased in steatotic cells, while synthesis of cholesterol and fatty acids were decreased. Lipid accumulation in IHH was associated with an increased apoptosis and an inhibition of cell proliferation and viability. No detectable changes in genes associated with insulin resistance were observed in steatotic cells, but signalling induced by insulin was more efficient in steatotic IHH as compared to control cells. We conclude that IHH represent a new valuable model of steatosis, not associated with insulin resistance, to study at both the genetic and functional level factors involved in the process of lipid accumulation and steatosis-associated liver injury.

MRI and ultrasound for hepatic fat quantification:relationships to clinical and metabolic characteristics of pediatric nonalcoholic fatty liver disease

OBJECTIVE

The aims of this study were to evaluate hepatic steatosis severity in a series of obese children through both magnetic resonance imaging (MRI) and ultrasound, and to correlate imaging findings to clinical and metabolic characteristics of the study population.

METHODS

Fifty obese children presenting hepatomegaly and/or elevated aminotransferases were candidates for assessment of hepatic fat fraction (HFF) by MRI. All subjects underwent dual energy X-ray absorptiometry scan measurement, and liver ultrasound scanning. Fasting blood samples were taken for the estimation of serum concentrations of glucose, insulin, leptin, aminotransferases and serum lipid profile.

RESULTS

A diagnosis of fatty liver was established by MRI in 20 (40%) children; of these, 12 had HFF of 9-18%, while the remaining ones had HFF of 19% or higher. HFF was not correlated to age, SDS-BMI, pubertal status and fat mass. HFF was positively associated with serum concentrations of alanine aminotransferase (ALT; r=0.62; p<0.0001) and AST (r=0.39; p=0.006), as well as with insulin (r=0.44; p=0.001) and insulin resistance (r=0.49; p<0.0001). Overall, ultrasound correlated well with MRI (p<0.0001). However, HFF ranged greatly in subjects with moderate (2-37%) as well as with severe (11-25%) degree of ultrasound hepatic steatosis. In fact, the mean hepatic fat fraction in children with severe steatosis was not statistically different from that found in patients with moderate steatosis (p=0.98). In multiple regression analysis, the most powerful predictors of elevated ALT, after correction for age, gender, BMI and pubertal status, were insulin resistance (p<0.01) and MRI HFF (p<0.0001).

CONCLUSIONS

Unlike sonography, an operator-dependent procedure, MRI is not subject to interpretation or inter-observer variation, and may be more useful than ultrasound for the monitoring of young patients with hepatic steatosis.

Bifendate treatment attenuates hepatic steatosis in cholesterol/bile salt- and high-fat diet-induced hypercholesterolemia in mice

Effects of bifendate, a synthetic intermediate of schisandrin C (a dibenzocyclooctadiene derivative), on liver lipid contents were investigated in experimentally-induced hypercholesterolemia in mice. Hypercholesterolemia was induced by either chronic administration of cholesterol/bile salt or feeding a high-fat diet containing cholesterol and/or bile salt. Hepatic and serum total cholesterol levels were significantly increased (42-268% and 23-124%, respectively) in cholesterol or high-fat diet-treated mice, when compared with control animals receiving vehicle or normal diet. Hepatic triglyceride level was increased (up to 108%), but serum triglyceride level was significantly reduced by 23-63% in hypercholesterolemic mice. Daily administration of bifendate (0.03-1.0 g/kg, i.g.) for 4 days decreased hepatic levels of total cholesterol (9-37%) and triglyceride (10-37%) in hypercholesterolemic mice. Supplementing the high-fat diet with bifendate (0.25%, w/w) caused decreases in hepatic total cholesterol (25-56%) and triglyceride (22-44%) levels following 7 or 14 days of experiment, respectively, when compared with animals fed with high-fat diet not supplemented with bifendate. While fenofibrate treatment decreased both hepatic and serum lipid levels in hypercholesterolemic mice, bifendate treatment did not reduce serum lipid levels. Bifendate and fenofibrate caused an increase (10-41% and 59-98%, respectively) in hepatic index of hypercholesterolemic mice. The results indicate that bifendate treatment can invariably decrease hepatic (but not serum) lipid levels in various mouse models of hypercholesterolemia.

Non-alcoholic fatty liver disease (NAFLD)--a novel common aspect of the metabolic syndrome

Non-alcoholic fatty liver disease (NAFLD) is emerging as one of the most common liver disorders claiming the urgent attention of both medical professionals and the public sphere because of the imminent epidemic of advanced liver injury that appendages epidemic of obesity. Recent research reveals simple triglyceride accumulation in hepatocytes (i.e., liver steatosis) frequently becoming complicated by inflammation (i.e., non-alcoholic steatohepatitis, or NASH) that may progress into more advanced stages of the disease including cirrhosis or, eventually, hepatocellular carcinoma. The exact mechanisms of the progression of NAFLD into overt NASH and advanced disease stages are largely unknown. There is urgent need in terms of both intensive research pursuits and effective practical measures to deal with this common threat.