The relationship between fatty liver and hyperinsulinemia in obese Japanese children

Percentage of overweight is overestimated in children of short stature

BACKGROUND

The prevalence of overweight and obesity has increased, not just in adults but also in children. In Japan, the percentage of overweight (POW) is widely used for the estimation and assessment of percentage body fat (PBF) for children. We examine whether there is a difference between normal height and short stature children in terms of the relationship between POW and PBF.

METHODS

A total of 321 children of normal height (163 boys, 158 girls) and 106 children with short stature (78 boys, 28 girls) were assessed according to sex. Percentage of overweight was used to represent the degree of obesity. The PBF of the total body was examined by dual energy X-ray absorptiometry.

RESULTS

According to their PBF, normal height subjects of both sexes were classified as obese if they had a POW of more than 20%. However, short-stature subjects of both sexes were not classified as obese until the boys had a POW of 40%, and girls had a POW of 35%, respectively. Thus, overweight or obesity is overestimated in short stature children in both males and females with the rule "POW above 20% is recognized as obesity."

CONCLUSIONS

Percentage of overweight is commonly considered as a good surrogate measure for determining overweight and obesity in children of both sexes. However, this study has clarified that body fat accumulation is overestimated in children with short stature when using the POW measurement.

Association of Serum Bilirubin Level with Metabolic Syndrome and Non-Alcoholic Fatty Liver Disease: A Cross-Sectional Study of 1672 Obese Children

As in adults, obesity also plays a central role in the development of metabolic syndrome (MS) in children. Non-alcoholic fatty liver disease (NAFLD) is considered a manifestation of MS. Not only MS but also NAFLD seem to be inversely associated with serum bilirubin concentrations, an important endogenous tissue protector when only mild elevated. The aim of the study was to evaluate the association between serum bilirubin levels and the prevalence of MS and NAFLD in Italian obese children and adolescents. A retrospective cross-sectional study was performed in 1672 patients aged from 5 to 18 years. Clinical and laboratory parameters were assessed. NAFLD was measured by liver ultrasonography. The study was approved by the Ethical Committee of the Istituto Auxologico Italiano (research project code 1C021_2020, acronym BILOB). MS was present in 24% and fatty liver (FL) in 38% of this population. Bilirubin was not associated with FL and MS as a whole, but it was inversely associated only with selected components of MS, i.e., large WC, high blood pressure and high triglycerides. Our data suggest that bilirubin is not protective against MS and NAFLD in the presence of severe obesity.

Waist circumference as a marker for screening nonalcoholic fatty liver disease in obese adolescents

Objective:

To assess the relationship between the degree of waist circumference (WC) and nonalcoholic fatty liver disease (NAFLD) in obese adolescents of both genders, analyzed according to quartiles of WC.

Methods:

Cross-sectional study that involved 247 obese adolescents aged 12–19 years. Mean values of the nutritional parameters and serum analyses were compared with the groups using the independent t-test. Pearson correlation coefficient was used to determine the relationship of the parameters studied. Chi-square test for trend was used to determine the relationship between the prevalence of the NAFLD and WC quartile by gender.

Results:

NAFLD were presented in 60% of the study participants. Obese adolescents in the 3rd and 4th quartiles of WC presented higher prevalence of NAFLD when compared with that in the 1st quartile in both genders. The NAFLD patients had significantly higher values for body weight, BMI (body mass index), BAZ-score (BMI-for-age z-scores), total fat (% and kg), WC, visceral fat, insulin, insulin resistance index (HOMA-IR), aspartate aminotransferase and alanine aminotransferase, when compared with non-NAFLD obese adolescents.

Conclusions:

In conclusion, the results presented here suggest that an increase in WC can reliably predict the risk of NAFLD in obese adolescents. This is a low cost and easy-to-use tool that can help in screening in adolescents.

A comprehensive review of noninvasive liver fibrosis tests in pediatric nonalcoholic Fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) and its spectrum ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) and fibrosis have been increasing in the pediatric population. The presence and severity of fibrosis in patients with NAFLD are important prognostic factors for the risk of disease progression to cirrhosis. The gold standard for staging liver fibrosis is a liver biopsy. However, given the risks of this procedure, especially in the pediatric population, the development of noninvasive markers to diagnose and monitor progression of NAFLD is desirable. This paper will review recently developed noninvasive methods for diagnosing liver fibrosis in children with NAFLD. These include simple fibrosis scores, advanced biochemical markers, and radiologic imaging studies. Simple fibrosis scores use readily available laboratory tests; available one include AST/ALT ratio, AST to platelet ratio index (APRI), fibrosis (FIB)-4 index, NAFLD fibrosis score (NFS), pediatric NAFLD fibrosis index (PNFI), and pediatric NALFD fibrosis score (PNFS). Advanced biochemical markers include biomarkers of hepatocyte cell death such as cytokeratin 18 fragment levels, and markers of extracellular matrix turnover such as the Enhanced Liver Fibrosis (ELF) test and hyaluronic acid. Radiologic imaging studies estimate liver stiffness as a surrogate for liver fibrosis; these include transient elastography (TE), magnetic resonance elastography (MRE), and acoustic radiation force impulse imaging (ARFI).

[Waist circumference as a marker for screening nonalcoholic fatty liver disease in obese adolescents]

OBJECTIVE

To assess the relationship between the degree of waist circumference (WC) and nonalcoholic fatty liver disease (NAFLD) in obese adolescents of both genders, analyzed according to quartiles of WC.

METHODS

Cross-sectional study that involved 247 obese adolescents aged 12-19 years. Mean values of the nutritional parameters and serum analyses were compared with the groups using the independent t-test. Pearson correlation coefficient was used to determine the relationship of the parameters studied. Chi-square test for trend was used to determine the relationship between the prevalence of the NAFLD and WC quartile by gender.

RESULTS

NAFLD were presented in 60% of the study participants. Obese adolescents in the 3rd and 4th quartiles of WC presented higher prevalence of NAFLD when compared with that in the 1st quartile in both genders. The NAFLD patients had significantly higher values for body weight, BMI (body mass index), BAZ-score (BMI-for-age z-scores), total fat (% and kg), WC, visceral fat, insulin, insulin resistance index (HOMA-IR), aspartate aminotransferase and alanine aminotransferase, when compared with non-NAFLD obese adolescents.

CONCLUSIONS

The results presented here suggest that an increase in WC can reliably predict the risk of NAFLD in obese adolescents. This is a low cost and easy-to-use tool that can help in screening in adolescents.

Improvement in nonalcoholic fatty liver disease and metabolic syndrome in adolescents undergoing bariatric surgery

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children. It is linked to obesity and the metabolic syndrome (MS), predisposing to future cirrhosis. The objective of this study was to demonstrate the effects that weight loss achieved with laparoscopic adjustable gastric band (LAGB) has on the metabolic parameters and NAFLD scores of obese adolescents with evidence of fatty liver disease.

METHODS

Adolescents undergoing LAGB were evaluated for NAFLD with evidence of fatty liver on preoperative sonogram, serum biochemistry, or both between 2005 and 2011. Primary endpoint was change in NAFLD scores after LAGB and secondary endpoint change in MS criteria.

RESULTS

Fifty-six out of 155 adolescents had evidence of fatty liver disease at presentation. The group consisted of 17 (30%) male and 39 (70%) females, mean age 16.1 years (range 14-17.8 yr). Preoperative body mass index (BMI) was 48.8 kg/m(2) (±7) dropping to 37.9 kg/m(2) (±8.3) at 12 months and 36.8 kg/m(2) (±8.2) at 24 months. Fifteen (27%) patients met the criteria for MS. When comparing 1-year postsurgery to presurgery, the NAFLD score decreased by an average of .68 (SD = 1.03, P<.01). The 2-year NAFLD score decreased by a mean of .38 (SD = .99, P = .01). The reoperation rate for band/port related complications was 10.7% at 2 years with no mortality. MS rates improved from 27% to 2% at 2 years (P< .01).

CONCLUSIONS

LAGB is a safe and effective operation for obese adolescents with NAFLD. There was significant improvement in NAFLD scores and resolution of MS.

Outcomes of group-based treatment program with parental involvement for the management of childhood and adolescent obesity

OBJECTIVE

An uncontrolled study was conducted to evaluate the effects of a group-based program on weight control, metabolic profiles, and obesity-related complications in obese youth.

METHODS

The program consisted of an initial in-patient session and five group sessions, one, two, three, six, and nine months into the study, providing participants and their parents with information about the consequences of obesity and lifestyle modifications. The severity of obesity and obesity-related complications were evaluated at baseline and 12 months after the intervention. The participants' and their parents' perceptions of the program were assessed.

RESULTS

Of the obese youth recruited (n=126), 115 completed the study. Their percentage weight for height and percentage body fat decreased significantly (both p<0.001), and their insulin resistance, lipid profiles, and transaminases levels improved (all p<0.01). The prevalence of prediabetes, dyslipidemia, and elevated transaminases decreased significantly (all p<0.05). The participants and their parents perceived the program as valuable.

CONCLUSION

A group-based program is effective in managing childhood obesity, improving metabolic profiles, and alleviating certain obesity-related complications.

PRACTICE IMPLICATIONS

A group-based program that provides education and raises the awareness of obese children and their parents about the consequences of obesity is an effective model for treating childhood obesity.

Hepatic steatosis and severity-related factors in obese children

BACKGROUND AND AIM

Obesity is an important health-care problem in developed countries. It is considered a multisystemic disease, but it may also affect the liver, thus provoking non-alcoholic fatty liver disease. This disease has been less extensively studied among children than among adults. We propose to analyze the prevalence of hepatic steatosis among a pediatric population within an area in southern Europe besides the variables associated with its development and severity.

METHODS

Cross-sectional study carried out on a population of children aged 6-14 years inclusive, using abdominal ultrasound as a method to determine the presence and severity of hepatic steatosis; in addition, anthropometric and blood-tested parameters were examined to determine which of these were associated with steatosis.

RESULTS

One hundred forty-four children were analyzed, 84 male (58.3%). Steatosis was detected in 50 children (34.7%; 95% confidence interval [CI]: 26.0-42.0%). In six of these cases (12%), elevated aminotransferase levels were recorded. Factors found to be associated with steatosis were body mass index ≥ 99th percentile (odds ratio [OR] 3.58, 95% CI 1.16-15.6) and the level of alanine aminotransferase (ALT) (OR 1.08, 95% CI 1.03-1.13), while its severity was associated with ALT (OR 1.17, 95% CI 1.09-1.28). A level of ALT < 23.5 UI/dL predicted lack of severe steatosis with an area under receiver operating characteristic curve of 0.805 (95% CI 0.683-0.927).

CONCLUSIONS

Non-alcoholic fatty liver disease is common in the obese pediatric population in our geographical area. High levels of ALT are associated with severe steatosis, although having ALT above the normal range is not common. Also, the lack of severity of steatosis can be predicted in a subgroup of children with obesity.

Serum retinol-binding protein 4 is independently associated with pediatric NAFLD and fasting triglyceride level

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is identified as a major liver disease in children. The present study aimed to identify the prevalence and predictors of pediatric NAFLD and the correlation between serum retinol-binding protein 4 (RBP4) levels and metabolic characteristics in children.

METHODS

A total of 748 schoolchildren, ages 6 to 12 years, were enrolled in 2009. The body weight and height were measured in the morning before intake. Laboratory tests included overnight fasting serum lipids, insulin, liver enzymes, and RBP4 levels. Hepatic steatosis was determined by ultrasound in 219 volunteers.

RESULTS

The rates of NAFLD were 3% in the normal-weight, 25% in the overweight, and 76% in the obese children. Twenty (22%) of obese children had abnormal alanine aminotransferase (ALT) levels. In children with NAFLD, younger age and higher body mass index (BMI), insulin/homeostasis model of assessment, and male sex rate were associated with abnormal liver function. Stepwise increments in BMI, insulin, homeostasis model of assessment, and ALT were found in children with normal livers to simple steatosis, and to steatosis with abnormal ALT. Multiple logistic regression analysis confirmed that serum RBP4 levels (P = 0.048), ALT (P = 0.048), and BMI (P < 0.001) were independently predictors of pediatric NAFLD. Moreover, multiple linear regression analysis revealed that only serum triglycerides levels were positively related to RBP4 levels (P < 0.001).

CONCLUSIONS

Higher RBP4 and ALT levels as well as BMI are independently associated with pediatric NAFLD in Taiwan. In addition, an increment in RBP4 levels was positively correlated to hypertriglyceridemia in children.

Relationship between beta-globin gene carrier state and insulin resistance

Objective

To assess the relationship between being beta globin gene carrier and developing insulin resistance.

Methods

This study was conducted on 164 subjects including 82 healthy ones and 82 patients with beta thalassemia minor (microcytosis (MCV <80 fl) and hypochromia (MCH <25 pg) and HbA2 ≥ 3.5% using HPLC). Fasting blood glucose (FBS) values of 100–125 mg/dl were considered as impaired fasting glucose, and above 125 mg/dl as diabetes mellitus. Two hours After 75 gram glucose load(GTT), blood sugar level of 140–199 mg/dl was considered as impaired glucose tolerance and above 199 mg/dl as diabetes mellitus. Insulin resistance was diagnosed based on homeostasis model assessment method (HOMA).

Results

According to FBS and BS2hPG values, the percentages of diabetes mellitus, pre diabetes, and normal glucose tolerance in case group was 8.5%, 9.8% and 81.7%, respectively. There was no case of diabetes mellitus in control group and 6.1% of this group were pre diabetic and 93.9% of them had normal glucose tolerance test (P = 0.02). Relative risk for diabetes mellitus and insulin resistance in the cases with minor thalassemia was 2 (95% CI: 1.8-2.5) and 2.02 (95% CI: 1.7-2.4), respectively.

Conclusion

The risk of developing diabetes and insulin resistance in patients with thalassemia minor is two times greater than the general population. Considering the high serum levels of CRP in these cases, the inflammation noted in liver cells could be considered as the underlying cause of insulin resistance, impaired glucose tolerance and diabetes in these patients.

Effect of a 10-week weight loss camp on fatty liver disease and insulin sensitivity in obese Danish children

BACKGROUND AND OBJECTIVE

Childhood nonalcoholic fatty liver disease (NAFLD) associated with insulin resistance and obesity is a growing problem and increases the risk of cirrhosis, type 2 diabetes mellitus, and cardiovascular complications. We examined the effects of a 10-week "weight loss camp" residency in obese children on the prevalence and degree of NAFLD and insulin sensitivity with 12-month follow-up.

METHODS

At the camp, 117 obese white children (body mass index 28.0 ± 3.6  kg/m, age 12.1 ± 1.3 years) exercised moderately for 1 hour/day and restricted their energy intake to induce weight loss. NAFLD was diagnosed and graded using ultrasound and transaminasemia. Insulin sensitivity and glucose tolerance were assessed using homeostasis model assessment and oral glucose tolerance test. We performed anthropometric measurements and determined body composition using bioimpedance. Data were collected from 71 of 117 children at entry, after the 10 weeks at the camp, and 12 months after the camp ended.

RESULTS

The children showed an average weight loss of 7.1 ± 2.7  kg during the camp. At baseline, 43% had ultrasonographic liver steatosis, 50% elevated transaminases (>25  IU/L), and reduced insulin sensitivity. These abnormalities were mutually related and improved significantly during the camp (P ≤ 0.05). Liver fat improvement was sustained at 12 months. At the 12-month follow-up, 17 of 71 (24%) children maintained the body weight.

CONCLUSIONS

This short-term diet and exercise program induced weight loss, markedly improved all aspects of the threatening condition of NAFLD, and reduced insulin sensitivity in childhood obesity; 24% of the children maintained weight loss at least until the 12-month follow-up.

Pediatric nonalcoholic fatty liver disease: Overview with emphasis on histology

Nonalcoholic fatty liver disease (NAFLD) is a disease in which excessive fat accumulates in the liver of a patient without a history of alcohol abuse. This disease includes simple steatosis and nonalcoholic steatohepatitis (NASH). NAFLD/NASH is recognized as a hepatic manifestation of metabolic syndrome. In recent years, pediatric NAFLD has increased in line with the increased prevalence of pediatric obesity. The estimated prevalence of pediatric NAFLD is 2.6%-9.6%, and it is associated with sex, age, and ethnicity. With regard to the pathogenesis of NAFLD, the “two-hit” hypothesis is widely accepted and oxidative stress is thought to play an important role in the second hit. Although clinical symptoms, laboratory data, and imaging findings are important, liver biopsy is regarded as the gold standard for the diagnosis of NAFLD/NASH. In addition, liver biopsy is essential for assessing the degree of necro-inflammatory change and fibrosis in NASH. Two different types of steatohepatitis (type 1 and type 2 NASH) have been reported, with type 2 NASH being present in as many as 51% of pediatric NAFLD patients. However, we and others have observed that type 1 and 2 patterns commonly overlap. Although pharmacotherapy has been studied in clinical trials, lifestyle modification by diet and exercise remains the mainstay of treatment for NAFLD/NASH.

Pediatric nonalcoholic fatty liver disease: A clinical and laboratory challenge

The true prevalence of pediatric nonalcoholic fatty liver disease (NAFLD) is unknown. Challenges in determining the population prevalence of NAFLD include the type of test (and the reference intervals used to define normal and abnormal), the type of population (general population, hospital series), the demographic characteristics of the population sampled, and the nature of the study design. The natural history of pediatric NAFLD remains uncertain. The issue of when to perform a liver biopsy in children with suspected NAFLD remains controversial. Children with NAFLD but normal alanine aminotransferase are rarely investigated. However, evidence of alterations in glucose metabolism parameters should prompt a better understanding of the natural history of pediatric NAFLD not only in terms of the progression of liver disease but also regarding its potential relationship with other health outcomes such as type 2 diabetes mellitus and cardiovascular disease. This evidence could make liver biopsy mandatory in the majority of cases at risk of progressive and severe hepatic and extrahepatic disease. This conclusion, however, raises the question of the feasibility of liver biopsy assessment in an extremely large at risk population, and of the cost/effectiveness of this policy. There is a considerable, continuous interest in reliable, noninvasive alternatives that will allow the prognosis of pediatric NAFLD to be followed in large community or population-based studies.

Obese boys at increased risk for nonalcoholic liver disease: evaluation of 16,390 overweight or obese children and adolescents

OBJECTIVE

Comorbidities of childhood obesity challenge health-care systems in Europe. Further, there is a lack of population-specific prevalence data and diagnostic strategies available, especially for obesity-related disturbances of liver function. Therefore, the prevalence of elevated liver enzymes and their relationship to biological parameters were studied in a large pediatric obesity cohort.

METHODS

In 111 specialized pediatric obesity centers in Germany, Austria and Switzerland, 16,390 children and adolescents (age 12.4±2.6 years, 58% boys) were categorized as overweight (body mass index (BMI) >90th percentile) and obese (>97th percentile) and studied for related comorbidities, especially nonalcoholic fatty liver disease (NAFLD; as defined by aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) >50 U l(-1)). Data were collected using a standardized software program (APV) for longitudinal multicenter documentation. Pseudonymized data were transmitted for central statistical analysis.

RESULTS

In this pediatric cohort, 16% of the study population was overweight, 46% obese and 35% extremely obese (>99.5th percentile extreme obesity (Xob)). NAFLD was present in 11% of the study population, but predominantly in boys (boys vs girls; 14.4:7.4%; P<0.001), in Xob (obese vs Xob; 9.5:17.0%; P<0.001) and in older age (< 12 vs ≥12 years; 8:12%; P<0.001; adjusted for BMI). ALT >50 U l(-1) was significantly associated with fasting insulin and BMI-SDS. In multiple logistic regression models, Xob and male gender were strongly associated with NAFLD (odds ratio Xob vs normal weight=3.2; boys vs girls OR=2.3).

CONCLUSION

In a large cohort of overweight and obese European children and adolescents, markers of nonalcoholic liver disease, especially ALT, are frequent and predicted by Xob and male gender. The results underline the epidemiological dimension of this obesity-related morbidity even in childhood. Therefore, at least ALT is recommended as a screening parameter in basic care.

Risk factors for liver steatosis in obese children and adolescents

BACKGROUND

Concurrent with the recent rise of the incidence in obesity, nonalcoholic fatty liver disease is increasingly prevalent in childhood. The aim of this study was to identify non-invasive biomarkers for liver steatosis in obese children and adolescents.

METHODS

We used a cross-sectional study to examine risk factors for liver steatosis in obese children and adolescents. Sixty-nine obese subjects aged 6-17 years were recruited. The diagnosis of liver steatosis was made by liver ultrasonography. Anthropometric, serum biochemical variables, and oral glucose tolerance tests were measured.

RESULTS

Thirty-eight (55.1%) subjects had liver steatosis. Elevated alanine aminotransferase levels (> 30 IU/L in boys and >19 IU/L in girls) were found in 27 (71.1%) of the 38 subjects with liver steatosis. In multivariate logistic regression analysis, liver steatosis was associated with waist circumference and the change of plasma glucose level before and after oral glucose tolerance testing (C-OGTT). For every 5 cm increase in waist circumference, there was an odds ratio of 1.391 for predicting liver steatosis (95% confidence interval: 1.009-1.916, p = 0.044). C-OGTT was the only laboratory variable that independently predicted liver steatosis, with an odds ratio of 1.198 (95% confidence interval: 1.022-1.404, p = 0.026) for each 5 mg/dL of increase.

CONCLUSION

In this hospital-based sample of obese children and adolescents, liver steatosis was common. Liver steatosis was positively associated waist circumference and C-OGTT. These findings have implications for screening liver steatosis in obese children and adolescents.

Obesity in children and adolescents: the relation between metabolic syndrome and non-alcoholic fatty-liver disease

This article aims to review clinical and diagnostic aspects of non-alcoholic fatty liver disease associated with obesity and its relation to metabolic syndrome in children and adolescents. An on-line search was carried out of original articles in the Medical Literature Analysis and Retrieval System Online (MEDLINE), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) and Scientific Eletronic Library Online (SciELO) databases, using the following key words: "hepatic steatosis", "nonalcoholic fatty liver diseases", "overweight", "obesity", "children", "adolescents", "ultrasound" and "metabolic syndrome" in English and Portuguese. Two hundred and seventy-five articles were initially selected, all published between 1993 and 2008. After reading this was narrowed down to 67. The literature consulted revealed no consensus regarding the need to screen for metabolic syndrome and non-alcoholic fatty liver disease, especially in obese children and adolescents and those who have excess fat in the abdominal region. An ultrasound examination of the liver is typically used for screening and, in the case of children who present alterations in aminotransferases in addition to fatty infiltration of the liver, a strict clinical follow-up and a liver biopsy are recommended if these symptoms do not disappear on treatment.

Is there any association between high-density lipoprotein, insulin resistance and non-alcoholic fatty liver disease in obese children?

Non-alcoholic fatty liver disease (NAFLD) is estimated to occur in about 50% of obese children. The purpose of this study is to examine the association of anthropometric, biochemical and liver indexes in obese children with and without NAFLD and its relation with insulin resistance (IR). Forty-three obese children participated in the study. NAFLD was diagnosed by ultrasonography. Liver indices (SGOT, SGPT), lipid profile, glucose and insulin levels were performed in all patients. IR was measured by means of the homeostasis model assessment and oral glucose insulin sensitivity. Among the 43 obese patients, 18/43 (41.8%) had NAFLD based on ultrasonography. Fifty percent of them had mild steatosis and 50% had moderate/severe steatosis. In logistic regression analysis of factors associated with NAFLD, homeostasis model assessment IR (ExpB, 1.607; 95% confidence interval, 1.058-2.440; P <0.02) and high-density lipoprotein (0.952; 95% confidence interval, 0.814-1.075; P <0.03) were the most significant. IR, as has already been proved, is associated with NAFLD. Furthermore, high-density lipoprotein levels seem to play an additional role in predicting NAFLD in obese children.

Pediatric non-alcoholic fatty liver disease: Preventive and therapeutic value of lifestyle intervention

Nonalcoholic fatty liver disease (NAFLD), ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), and eventually cirrhosis and liver failure, is seen to be increasing amongst Western children. NAFLD rates are rising in parallel with the epidemic of childhood obesity, and in particular, fatty liver evolves more easily in NASH when poor dietary habits and sedentary lifestyle are combined. In fact, its general prevalence in the child population varies between 2.6% and 10%, but increases up to 80% in obese children. Since NASH is expected to become the most common cause of pediatric chronic liver disease in the near future, there is broad interest amongst clinical researchers to move forward, both in diagnosis and treatment. Unfortunately, to date, the expensive and invasive procedure of liver biopsy is seen as the gold standard for NASH diagnosis and few noninvasive diagnostic methods can be applied successfully. Moreover, there are still no approved pharmacological interventions for NAFLD/NASH. Therefore, current management paradigms are based upon the presence of associated risk factors and aims to improve an individual’s quality of life, thus reducing NAFLD-associated morbidity and mortality. Today, lifestyle intervention (diet and exercise) is the treatment of choice for NAFLD/NASH. Thus far, no study has evaluated the potential preventive effect of lifestyle intervention on children at risk of NAFLD/NASH. Future studies will be required in this area with the perspective of developing a national program to promote nutrition education and increase physical activity as means of preventing the disease in individuals at risk. Here, we outline the clinical course, pathogenesis and management of NAFLD in children, highlighting the preventive and therapeutic value of lifestyle intervention.

Gender-specific prevalences of fatty liver in obese children and adolescents: roles of body fat distribution, sex steroids, and insulin resistance

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is known to have a gender-dimorphic prevalence in obese children. Less information is available on predictive factors for NAFLD in obese youths.

OBJECTIVE

The aim of the study was to examine the prevalence pattern and to identify clinical and laboratory markers associated with the risk for NAFLD.

DESIGN

This was a cross-sectional study.

SETTING

The study setting was a rehabilitation clinic.

STUDY PARTICIPANTS

A total of 532 obese subjects (291 girls) aged 8-19 yr participated in the study.

MAIN MEASUREMENTS

Steatosis hepatis and visceral fat mass were determined by ultrasound. Laboratory tests included serum lipids, adiponectin, high-sensitivity C-reactive protein, sex steroids, and an oral glucose tolerance test.

RESULTS

Prevalence of hepatic steatosis was significantly higher in boys (41.1%) than in girls (17.2%) and was highest in postpubertal boys (51.2%) and lowest in postpubertal girls (12.2%). Severity of steatosis was associated with increased visceral fat mass, insulin resistance, lower adiponectin levels, and higher blood pressure. Three factors were extracted from the panel of investigated parameters by principal component analysis. Logistic regression analysis revealed significant associations of simple steatosis with the "insulin resistance and visceral fat" factor and the "body fat distribution and inflammation" factor in both genders and additionally with the "steroid hormones" factor in girls. Risk for steatosis hepatis with concomitantly elevated ALT was associated only with "insulin resistance and visceral fat" in girls and with all three factors in boys.

CONCLUSION

Our results suggest significant associations of NAFLD with markers of visceral obesity and insulin resistance in both genders and gender-specific associations with parameters of body fat distribution and sex steroids.

The metabolic syndrome and nonalcoholic fatty liver disease in children

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent in pediatric-age individuals, in parallel with increasing obesity, and can lead to liver inflammation, fibrosis, and even cirrhosis. NAFLD appears tightly linked with features of the metabolic syndrome (MetS). This review aims to reconsider the clinical presentation, laboratory and pathologic assessment, and treatment of NAFLD, with a focus on its relationship with the MetS.

RECENT FINDINGS

NAFLD occurs with a high prevalence and severity in obese, insulin-resistant adolescents, especially Hispanic males. Pediatric NAFLD may improve with lifestyle therapy and agents that improve insulin sensitivity. In youth, NAFLD appears tightly correlated with components of the MetS, especially visceral fat, which appears to predict fibrosis as well as liver fat. In addition, noninvasive techniques such as transient elastography may help provide data on fibrosis in youth with NAFLD and avoid biopsy.

SUMMARY

The close association between NAFLD and the MetS supports screening for other comorbidities associated with the MetS. Further research is urgently required to best identify effective therapies to prevent and treat NAFLD, but its close association with MetS argues for a focus on strategies designed to improve insulin resistance and components of the MetS.

Preventive effect of a melon extract rich in superoxide scavenging activity on abdominal and liver fat and adipokine imbalance in high-fat-fed hamsters

Studies showed that dietary antioxidants could be a therapy against obesity that is associated with a state of oxidative stress. Thus, this paper investigates whether a dietary ingredient, a melon juice extract rich in superoxide dismutase, would prevent the development of such obesity in hamsters. Five groups received a standard diet or a high-fat diet (HF) plus a daily gavage with water (control) or extract at 0.7, 2.8, or 5.6 mg/day. After 84 days, the higher dose lowered triglyceridemia (68%), production of liver superoxide anion (12%), mitochondrial cytochrome c oxidase activity (40%), lipid and protein oxidation products (35 and 35%, respectively), and leptinemia (99%) and increased adiponectinemia (29%), leading to a concomitant reduction in insulinemia (39%), insulin resistance (41%), and abdominal lipids (25%). The extract triggered a remarkable decrease of liver lipids (73%) and fully prevented the steatohepatitis induced by the HF diet. Chronic consumption of this melon extract may represent a new alternative to reduce obesity induced by a high-fat diet.

Nonalcoholic fatty liver disease as a comorbidity of childhood obesity

Childhood obesity is a worldwide health problem associated with an increase in the prevalence and severity of comorbid conditions including nonalcoholic fatty liver disease (NAFLD). The increasing number of children with NAFLD presents a major public health concern. This review focuses on the recent advancements in the understanding of the epidemiology, diagnosis, histology, pathogenesis and treatment of pediatric NAFLD and highlights ongoing challenges and unmet needs in the area.

Ghrelin and leptin modulate immunity and liver function in overweight children

BACKGROUND

The rising prevalence of obesity represents a growing worldwide public health problem. Interactions of adipocytokines and low-grade systemic inflammation presently are considered important in the development of obesity, as well as associated chronic disease including bronchial asthma, obesity-related liver disease and type 2 diabetes mellitus. The purpose of the present study was to investigate metabolic, hormonal, immunologic and inflammatory factors in overweight children and to further clarify possible immunomodulatory effects of obesity-related hormones and cytokines.

METHODS

Forty-nine prepubertal overweight children and 49 age-matched controls of normal weight without underlying disease were enrolled. Levels of plasma ghrelin and serum leptin, cytokines (interleukin [IL]-4, IL-10, IL-12, 1L-13), C-reactive protein, immunoglobulin, and insulin were measured, and liver function tests were done to better understand their status in the setting of obesity.

RESULTS

Overweight subjects had significantly higher measures of adiposity (body mass indexI, % body fat) and had significantly higher serum levels of IgG, IgA and IgE than non-obese children (P = 0.038, 0.0043, 0.0034, respectively); the opposite was true for IgM (P = 0.025). The incidence of presumed non-alcoholic fatty liver disease was 28.6% in overweight children. In overweight children, serum leptin levels were associated with liver function index (aspartate aminotransferase/alanine aminotransferase ratio) and serum insulin levels. Some elevated immunoglobulin levels significantly correlated with plasma ghrelin levels and liver function index.

CONCLUSIONS

It is possible that appetite-regulating hormones modulate both humoral immunity and liver function. Further studies with a larger number of subjects are needed to clarify the precise mechanisms of this association.

Treatment of non-alcoholic fatty liver disease with metformin versus lifestyle intervention in insulin-resistant adolescents

The presence of fatty liver per ultrasound and liver-associated enzymes were measured in a select cohort of youth with both obesity and insulin resistance, and the effect of metformin on these parameters evaluated. Fifty obese, multiethnic, insulin-resistant adolescents (mean age 15.1 yr, mean body mass index 39.8 kg/m2) were randomized to receive lifestyle recommendations plus either twice per day doses of 850 mg of metformin or placebo. Fasting and post-glucose challenge biochemistries and liver ultrasounds were compared at baseline and 6 months. The prevalence of fatty liver was 74%, elevated alanine aminotransferase (ALT) 14%, aspartate aminotransferase (AST) 14%, and gamma-glutamyl transferase (GGT) 17%. Fatty liver was mild in 23%, moderate in 31%, and severe in 46%. Fatty liver was more common in male and Hispanic subjects and elevated ALT more common in Hispanic subjects. Subjects with fatty liver appeared more insulin resistant (higher fasting insulin and triglycerides, lower high-density lipoprotein cholesterol) and had higher ALT and AST. At 6 months, mean ALT, GGT, and fasting insulin improved significantly in all subjects. Fatty liver prevalence (p < 0.04), severity (p < 0.04), and fasting insulin (p < 0.025) improved significantly with metformin compared to placebo. Non-alcoholic fatty liver disease (NAFLD) occurs with a high prevalence and severity in obese, insulin-resistant adolescents. While metformin plus lifestyle intervention appears promising, defining NAFLD therapies capable of preventing fibrosis and cirrhosis requires further study.

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.

Evaluation of focal fatty infiltration of the liver using color Doppler and contrast-enhanced sonography

PURPOSE

To investigate the vascular characteristics of focal fatty infiltration (FFI) in the liver using color Doppler sonography (CDUS) and contrast-enhanced sonography (CEUS).

METHODS

We prospectively examined 25 areas of FFI of the liver in 20 patients via conventional gray-scale sonography, CDUS, and CEUS. Cadence contrast pulse sequencing and the contrast agent SonoVue were used for CEUS examination. CEUS criteria for diagnosis of FFI were isoenhancement or hypoenhancement in the arterial phase and homogeneous isoenhancement in the portal and late phases.

RESULTS

CDUS revealed a draining vein in 4 of 9 (44%) lesions in the hepatic hilum, whereas CEUS revealed a draining vein in 8 (89%) lesions. A vein was associated with the 2 lesions located at the edge of segment II on both CDUS and CEUS. Blood flow was seen on both CDUS and CEUS in the 2 lesions adjacent to the falciform ligament. In one patient, CDUS and CEUS revealed the mid-hepatic vein coursing between 2 FFIs. In the arterial phase of CEUS, the lesions were hypoenhancing in 44% (11/25), iso-enhancing in 44% (11/25), and hyperenhancing in 12% (3/25). In the portal phase and in the late vascular phase, all 25 lesions (100%) were iso-enhancing. Sensitivity of combined sonography and CDUS in the diagnosis of FFI was 44%, and overall accuracy was 81%. The sensitivity of CEUS in the diagnosis of FFI was 88%, and its overall accuracy was 96%.

CONCLUSION

FFI in the porta hepatis is correlated with aberrant venous drainage. FFI around the falciform ligament may be related to divergence of the portal vein or unusual blood supply. In the arterial phase of CEUS, FFI lesions were iso-enhancing as often as they were hypoenhancing.

Relationship between insulin resistance and serum alanine aminotransferase as a surrogate of NAFLD (nonalcoholic fatty liver disease) in obese Korean children

There has been increasing number of obese children who accompany obesity-related comorbidities. It has been known that nonalcoholic fatty liver disease (NAFLD) as one of obesity-related comorbidities is related with insulin resistance. So, we investigated the relation between insulin resistance and NAFLD, using serum alanine aminotransferase (ALT) as a surrogate of NAFLD among obese children in Korea. The study subjects were 909 obese children aged 9-12 years (boys 613, girls 296). Body mass index (BMI), waist circumference (WC), blood pressure, fasting blood glucose, fasting insulin, lipid profile were measured. ALT, liver enzyme was used as a surrogate of NAFLD and homeostasis model assessment of insulin resistance (HOMA-IR) was used as the index of insulin resistance. The prevalence of elevated serum ALT (>or=40 mg/dl) was 33.4% in boys, and 19.6% in girls respectively. In boys, ALT was correlated with BMI, waist circumference, total cholesterol, triglyceride, HDL-cholesterol, systolic and diastolic blood pressure, HOMA-IR, fasting serum insulin. Odds ratio for HOMA-IR against the elevated ALT (>or=40 mg/dl) was 1.061 (95% confidence interval, 1.020-1.103, P=0.003). In girls, ALT was correlated with BMI, waist circumference, total cholesterol, triglyceride, glucose, systolic and diastolic blood pressure, HOMA-IR, fasting serum insulin. Odds ratio for HOMA-IR against the elevated ALT (>or=40 mg/dl) was 1.042 (95% confidence interval, 0.998-1.088, P=0.063). Among obese Korean children, insulin resistance and ALT, lipid profile, BMI, WC, blood pressure showed significant correlation. Especially, in boys, higher ALT is founded to be independently associated with insulin resistance.

Association of raised liver transaminases with physical inactivity, increased waist-hip ratio, and other metabolic morbidities in severely obese children

OBJECTIVE

To identify factors associated with raised alanine transaminase, aspartate transaminase, and gamma-glutaryl transferase in severely obese children

PATIENTS AND METHODS

In all, 201 children with early-onset obesity and greater than 140% ideal weight for height were recruited. Anthropometric and body fat measurements, fasting blood tests, and oral glucose tolerance tests were performed.

RESULTS

The mean and standard deviation (SD) for age was 11.1 (3.0) years, for weight for height 170.5% (22.7%), and for percentage body fat was 40.7% (5.2%). Elevated liver transaminases were present in 53 subjects (26.4%), who were therefore at risk for nonalcoholic fatty liver disease, and was associated with male sex (odds ratio [OR] 2.144, 95% confidence interval [CI] 1.033-4.448), Chinese ethnicity (OR 2.062, 95% CI 1.038-4.096), reduced physical activity (OR 2.389, 95% CI 1.163-4.909), insulin resistance (P < 0.05), elevated triglyceride levels (P = 0.029), and increased waist-hip ratio (P = 0.005). Stepwise logistic regression analysis of the main factors as covariates revealed Chinese ethnicity, waist-hip ratio, reduced physical activity, and homeostasis model assessment index were significant predictors. Alanine transaminase/aspartate transaminase were not well correlated with percentage body fat and weight for height. Subjects with type 2 diabetes mellitus and impaired glucose tolerance were more likely to have raised hepatic transaminases (OR 6.176, 95% CI 1.326-28.754). The severity of metabolic syndrome correlated with increasing aspartate transaminase, alanine transaminase, and gamma-glutaryl transferase (P < 0.01).

CONCLUSIONS

Insulin resistance, truncal adiposity, and physical inactivity are major determinants potentially modifiable to reduce risk of nonalcoholic fatty liver disease. Increasing physical activity levels were associated with decreasing insulin resistance and transaminases, despite lack of correlation with waist-hip ratio, which supports the direct benefit of regular physical activity in preventing nonalcoholic fatty liver disease.

Review article: epidemiology, pathogenesis and potential treatments of paediatric non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of paediatric liver disease. Similar to NAFLD in adults, NAFLD in children is associated with obesity and insulin resistance and requires liver histology for diagnosis and staging. However, significant histological differences exist between adult and paediatric NAFLD to warrant caution in extrapolation of adult data.

AIM

To review the available data on the epidemiology, pathogenesis, diagnosis and treatment of paediatric NAFLD.

METHODS

Relevant articles were identified by Medline searches using the keywords: nonalcoholic fatty liver disease, steatohepatitis, obesity and children.

RESULTS

The rise in childhood obesity has been accompanied by an increase in paediatric NAFLD. Age, gender and race/ethnicity are significant determinants of risk, and sex hormones, insulin sensitivity and adipocytokines are implicated in the pathogenesis of paediatric NAFLD. There is no consensus for treatment of NAFLD; however, data suggest that diet, exercise and some pharmacological therapies may be of benefit.

CONCLUSIONS

To evaluate and effectively treat paediatric NAFLD, the pathophysiology and natural history of the disease should be clarified and non-invasive methods for screening, diagnosis, and longitudinal assessment developed. Randomized, controlled, double-blind trials of pharmacological therapies in children with biopsy-proven disease are necessary.

Presence of the metabolic syndrome in obese adolescents predicts impaired glucose tolerance and nonalcoholic fatty liver disease

PURPOSE

To evaluate whether the presence of metabolic syndrome (MS) in obese adolescents is associated with other comorbidities of obesity

METHODS

A total of 85 obese teens (70% female and 30% male) with fasting insulin >25 microU/ml and family history of type 2 diabetes mellitus and/or acanthosis nigricans were studied. Mean age was 15.8 +/- 1.7 years and body mass index (BMI) was 39.3 +/- 6.6 kg/m(2). Of the subjects, 54% were Hispanic and 35% black, 5% white, 5% American Indian, and 1% Asian. Laboratory analysis included fasting lipids, glucose, gamma-glutamyl transpeptidase (GGT), and oral glucose tolerance testing. Additional liver transaminase levels were determined and liver ultrasound (US) was performed to evaluate the presence and severity of fatty liver.

RESULTS

All subjects met MS criteria for children for waist circumference, 49% for blood pressure, 54% for high-density lipoprotein, 54% for triglycerides, and 20% for impaired fasting glucose (IFG) or impaired glucose tolerance [IGT]). In all, 47 subjects had three or more MS criteria. BMI was no different between groups with and without MS. Subjects with three or more MS criteria were more likely to have IGT (p = .004), elevated alanine aminotransferase (p = .039), elevated GGT (p = .036), fatty liver on US (p < .001), and more severe fatty liver (p = .001).

CONCLUSIONS

Abnormal glucose regulation and evidence of nonalcoholic fatty liver disease (NAFLD) were more common in subjects meeting three criteria for MS than in those meeting fewer criteria. The identification of MS provides value to the primary care provider. Those patients meeting criteria for MS should be evaluated for glucose intolerance and NAFLD.

Visceral adipose tissue area is an independent risk factor for hepatic steatosis

BACKGROUND AND AIM

Recent data indicate that hepatic steatosis is associated with insulin resistance, dyslipidemia and obesity (especially central body fat distribution). There have been few studies on the correlation between biopsy-proven hepatic steatosis and the above factors in a disease-free population. The aim of the present study was to evaluate the relation between hepatic steatosis assessed by biopsy and clinical characteristics including regional fat distribution measured by computed tomography (CT) in living liver donors.

METHODS

Laboratory data, liver/spleen Hounsfield ratio (L/S ratio), regional fat distribution by CT and liver status by biopsy were evaluated retrospectively in a total of 177 living liver donors without a history of alcohol intake.

RESULTS

The unpaired t-test showed that age, triglycerides (TG), high density lipoprotein, total cholesterol, alanine aminotransferase, body mass index, L/S ratio, visceral adipose tissue area (VAT) and subcutaneous adipose tissue area (SAT) were associated with hepatic steatosis. In the multiple logistic regression analysis, VAT (odds ratio 1.031, 95% CI 1.013-1.048, P < 0.01) and TG (odds ratio 1.012, 95% CI 1.004-1.020, P < 0.01) were independent risk factors of hepatic steatosis. Subgroup analysis also showed that VAT was an independent risk factor in men (odds ratio 1.022, 95% CI 1.003-1.041, P < 0.05) and women (odds ratio 1.086, 95% CI 1.010-1.168, P < 0.05).

CONCLUSION

Our results suggest that visceral abdominal adiposity is correlated with hepatic steatosis in healthy living liver donors.

Non-alcoholic fatty-liver disease in pediatric populations

The increasing prevalence of obesity is not only observed in adults. Children are affected by obesity and related diseases, such as chronic liver disease, more frequently than in the past. Nonalcoholic fatty-liver disease is an important cause of chronic liver disease and in the near future will become important worldwide. Considering this phenomenon, it is important for gastroenterologists and hepatologists to be aware of the presence of nonalcoholic fatty-liver disease in pediatric populations and to treat it adequately. This practice will have important benefits for future generations. This review discusses the most important aspects in epidemiology, diagnostics and treatment of nonalcoholic fatty-liver disease in children.

Update on non-alcoholic fatty liver disease in children

Non-alcoholic fatty liver disease (NAFLD) is probably the most common cause of liver disease in the pediatric community. It is closely associated with obesity and insulin resistance. NAFLD may lead to non-alcoholic steatohepatitis (NASH). Although NASH is a prerequisite for the definition of NAFLD in adults and children, distinct differences are often apparent in the extent or location of fat, inflammation and fibrosis. Confirmation of the diagnosis of NAFLD can usually be achieved by imaging studies; however, staging the disease requires a liver biopsy. Current treatment relies on weight loss and exercise, although various insulin-sensitizing agents, antioxidants and medications appear promising. The aim of this review is to summarize what is known about pediatric NAFLD in terms of prevalence, pathogenesis, diagnosis, histology and treatment.

Non-alcoholic fatty liver disease and childhood obesity

Obesity has emerged as a significant global health problem in the pediatric population. Pediatric liver disease is a serious complication of childhood obesity. Non-alcoholic steatohepatitis (NASH) is an entity in the spectrum of non-alcoholic fatty liver disease (NAFLD) ranges from fat in the liver--simple steatosis, NASH/ steatohepatitis--fat with in.ammation and/or fibrosis to advanced fibrosis and cirrhosis when fat may no longer be present. NASH is associated with obesity, diabetes, insulin resistance (IR), and hypertriglyceridemia. Children get NAFLD, and the incidence of this pediatric liver disease is rising as childhood obesity becomes increasingly prevalent. Although much remains to be learned about pediatric NAFLD, it is already evident that children with NASH risk progressive liver damage, including cirrhosis. Liver biopsy is required for definitive diagnosis, and other causes of fatty liver in childhood must be excluded. Gradual weight loss through increased regular exercise and a low-fat, low-refined carbohydrate diet appears to be effective. Drug treatments are being developed. The important message is that childhood obesity poses important health problems, including but not limited to potentially severe chronic liver disease. Early diagnosis of children who are only overweight is a worthy goal so that strategies to limit obesity can be instituted as early as possible. Identification of genetic risks is important, but management will invariably require changes in environmental factors. In addition to individual treatment, a multifaceted, societal initiative is required for solving the childhood obesity epidemic.

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.

Risk for nonalcoholic fatty liver disease in Hispanic youth with BMI > or =95th percentile

OBJECTIVES

To characterize children at risk for nonalcoholic fatty liver disease (NAFLD) and to explore possible mechanisms underlying the development of NAFLD in Hispanic youth with a body mass index > or =95th percentile.

PATIENTS AND METHODS

Hispanic nonoverweight (n = 475) and overweight (n = 517) children, ages 4 to 19 y, were characterized in terms of body composition (dual-energy x-ray absorptiometry), maturation (Tanner stage), diet (24-h recall), physical activity (accelerometry), fitness (maximal oxygen uptake), and biochemical profile (fasting alanine aminotransferase [ALT], glucose, insulin, and lipids; inflammation markers such as adiponectin, leptin, C-reactive protein, and soluble intercellular adhesion molecule-1; and total antioxidants) using standard laboratory techniques. Risk for NAFLD was defined by fasting serum ALT values >97.5th percentile for age- and sex-specific reference values.

RESULTS

Fasting serum ALT was elevated in 24% of overweight children and in only 4% of nonoverweight children. Therefore, to identify risk factors associated with elevated ALT, the remaining statistical analysis was restricted to the overweight group. The percentage of overweight children with elevated ALT did not differ by sex, age, or Tanner stage. Weight, body mass index, z score, waist-to-hip ratio, fat-free mass, fat mass, and percent truncal fat mass were higher in the overweight children with elevated ALT. Fasting insulin, glucose, and homeostasis model-insulin resistance were higher in the overweight children with elevated ALT, as were triglycerides, total cholesterol, low-density lipoprotein, thyroid-stimulating hormone, and triiodothyronine. Fasting serum leptin, C-reactive protein, and soluble intercellular adhesion molecule-1 were significantly higher and adiponectin was lower in the overweight children with elevated ALT.

CONCLUSIONS

The risk for developing NAFLD was high in the overweight Hispanic children. The proportion of "at risk" children was not influenced by gender, age, or maturation. The risk for elevated ALT was predicted by the severity of obesity, central adiposity, hyperinsulinemia, hypertriglyceridemia, elevated thyroid-stimulating hormone, and systemic inflammation.

The association between non-alcoholic fatty liver disease and insulin resistance in 20 obese children and adolescents

AIM

To investigate whether there are correlations between non-alcoholic fatty liver disease (NAFLD) and insulin resistance in obese children. For the first time, we present clinical data of 20 obese children with NAFLD, including an oral glucose tolerance test.

METHODS

Twenty obese children were diagnosed as having NAFLD by abdominal ultrasonography. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (gamma-GT) were reported. Insulin sensitivity was evaluated by oral glucose tolerance test, oral glucose insulin sensitivity (OGIS) and homeostasis is model assessment (HOMA) index. All parameters were compared to 20 obese age- and sex-matched patients without NAFLD.

RESULTS

With 81% the prevalence of insulin resistance according to HOMA or OGIS criteria was high in the NAFLD-patients compared to the other group with 63%. Statistically significant differences between both groups were found for mean serum ALT levels, mean glucose levels after 30, 60 and 90 minutes and mean insulin levels after 60 minutes of the glucose tolerance test.

CONCLUSION

The high prevalence of insulin resistance we found in children with NAFLD confirms the suggestion that there may be an association between insulin resistance and NAFLD in obese children and indicates that markers of insulin sensitivity could be useful screening parameters for NAFLD.

Lower Birth Weight Associated with Current Overweight Status Is Related with the Metabolic Syndrome in Obese Japanese Children

The purpose of this study was to clarify the relationship between lower birth weight and current overweight status and to examine the involvement of these factors in the development of the metabolic syndrome (MS) in obese Japanese children. We examined 97 obese boys (mean age 11.3 years; mean percentage overweight [POW] 52.4%) and 29 obese girls (mean age 11.1 years; mean POW 58.3%). The anthropometric measurements, blood pressure, fasting serum insulin and blood glucose, liver enzymes, lipids and lipoproteins were measured. Birth weight and gestational weeks were also recorded. The subjects were divided into either an MS group or a Non-MS group using criteria proposed for Japanese children. We compared the weight parameters (birth weight, current weight and current weight-to-birth weight ratio [WBWR]) between the two groups and analyzed the relationships between the weight parameters and metabolic derangements. There were no significant differences in age or anthropometric measurements between the two groups. However, birth weight in the MS group was lower than that in the Non-MS group, while WBWR of the MS group was higher than that in the Non-MS group. Blood pressure and serum insulin correlated positively with WBWR. These findings suggested that lower birth weight with current overweight status was associated with the MS in obese Japanese children. We were unable to clarify whether subjects with lower birth weight who achieved proper weight gains had the same risk as subjects with appropriate birth weight. However, they should be assisted to grow adequately to prevent future metabolic derangements.

Predictors of non-alcoholic fatty liver disease in obese children

OBJECTIVE

To evaluate predictors of non-alcoholic fatty liver disease (NAFLD) in obese children.

DESIGN

Cross-sectional study.

SUBJECTS

Two hundred and sixty-eight obese children not consuming alcohol and without hepatitis B or C were consecutively studied at an auxology clinic.

MEASUREMENTS

Alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl-transferase (GGT), cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides, uric acid, glucose, glucose during oral glucose tolerance testing (OGTT), insulin, insulin during OGTT, insulin resistance as estimated by homeostasis model assessment (HOMA), C-reactive protein (CRP), and systolic and diastolic blood pressure were measured. Fatty liver was diagnosed by ultrasonography using standard criteria. Univariable and multivariable logistic regression was used to evaluate predictors of NAFLD. All predictors except gender and pubertal status were modeled as continuous variables.

RESULTS

NAFLD was detected in 44% of obese children. At univariable analysis, male gender, Z-score of body mass index (BMI) (Z-BMI), ALT, AST, GGT, triglycerides, uric acid, glucose, glucose during OGTT, insulin, insulin during OGTT, HOMA, CRP and systolic blood pressure were predictors of NAFLD, whereas HDL-cholesterol and late-pubertal status were predictors of the normal liver. At multivariable analysis, however, only Z-BMI, ALT, uric acid, glucose during OGTT and insulin during OGTT were independent predictors of NAFLD.

CONCLUSION

Z-BMI, ALT, uric acid, glucose during OGTT and insulin during OGTT are independent predictors of NAFLD in Italian obese children, with most of the prediction explained by ALT and Z-BMI.

Alanine aminotransferase levels and fatty liver in childhood obesity: associations with insulin resistance, adiponectin, and visceral fat

BACKGROUND

Concurrent with the rise in obesity, nonalcoholic fatty liver disease is recognized as the leading cause of serum aminotransferase elevations in obese youth. Nevertheless, the complete metabolic phenotype associated with abnormalities in biomarkers of liver injury and intrahepatic fat accumulation remains to be established.

METHODS

In a multiethnic cohort of 392 obese adolescents, alanine aminotransferase (ALT) levels were related with parameters of insulin sensitivity, glucose, and lipid metabolism as well as adipocytokines and biomarkers of inflammation. A subset of 72 adolescents had determination of abdominal fat partitioning and intrahepatic fat accumulation using magnetic resonance imaging.

FINDINGS

Elevated ALT (> 35 U/liter) was found in 14% of adolescents, with a predominance of male gender and white/Hispanic race/ethnicity. After adjusting for potential confounders, rising ALT was associated with reduced insulin sensitivity and glucose tolerance as well as rising free fatty acids and triglycerides. Worsening of glucose and lipid metabolism was already evident as ALT levels rose into the upper half of the normal range (18-35 U/liter). When hepatic fat fraction was assessed using fast magnetic resonance imaging, 32% of subjects had an increased hepatic fat fraction, which was associated with decreased insulin sensitivity and adiponectin, and increased triglycerides, visceral fat, and deep to superficial sc fat ratio. The prevalence of the metabolic syndrome was significantly greater in those with fatty liver.

INTERPRETATION

Deterioration in glucose and lipid metabolism is associated even with modest ALT elevations. Hepatic fat accumulation in childhood obesity is strongly associated with the triad of insulin resistance, increased visceral fat, and hypoadiponectinemia. Hence, hepatic steatosis may be a core feature of the metabolic syndrome.

Pediatric nonalcoholic fatty liver disease: a critical appraisal of current data and implications for future research

Although population prevalence is very difficult to establish, nonalcoholic fatty liver disease (NAFLD) is probably the most common cause of liver disease in the preadolescent and adolescent age groups. There seems to be an increase in the prevalence of NAFLD, likely related to the dramatic rise in the incidence of obesity during the past 3 decades. Despite an increase in public awareness, overweight/obesity and related conditions, such as NAFLD, remain underdiagnosed by health care providers. Accurate diagnosis and staging of nonalcoholic steatohepatitis (NASH) requires liver biopsy. The development of noninvasive surrogate markers and the advancements in imaging technology will aid in the screening of large populations at risk for NAFLD. Two distinct histological patterns of NASH have been identified in the pediatric population, and discrete clinical and demographic features are observed in children with these 2 patterns. The propensity for NASH to develop in obese, insulin-resistant pubertal boys of Hispanic ethnicity or a non-Hispanic white race may provide clues to the pathogenesis of NAFLD in children. The natural history of pediatric NASH has yet to be defined, but most biopsies in this age group demonstrate some degree of fibrosis. In addition, cirrhosis can be observed in children as young as 10 years. While the optimal treatment of pediatric NAFLD has yet to be determined, lifestyle modification through diet and exercise should be attempted in children diagnosed with NAFLD. A large, multicenter trial of vitamin E and metformin is underway as part of the NASH clinical research network.

Alanine amino transferase concentrations are linked to folate intakes and methylenetetrahydrofolate reductase polymorphism in obese adolescent girls

OBJECTIVE

The objective of this study was to investigate the consequences of low dietary folate intake and the impact of the 677 C-->T methylenetetrahydrofolate reductase (MTHFR) common mutation on liver function in obese adolescents.

METHODS

Fifty-seven obese girls (BMI = 36.1 +/- 6.0 kg/m) aged 14.1 +/- 1.5 years were included before starting a weight reduction program. Dietary intakes for folate were assessed by means of an adapted food frequency questionnaire (n = 50). Liver enzymes, plasma lipids, glucose metabolism parameters, ferritin, homocysteine and erythrocyte folate content were measured in plasma or blood obtained under fasting conditions. The MTHFR 677 C-->T polymorphism, which is associated with decreased enzyme activity, was determined using PCR. Body composition was assessed using dual x-ray absorptiometry.

RESULTS

Twenty-three subjects were heterozygote (CT) for the mutation and 5 were homozygote (TT). An increase in alanine amino transferase (ALT) and ALT/aspartate aminotransferase ratio was associated with the mutation (F = 4.46, P = 0.016 and F = 5.92, P = 0.0049, respectively). Alanine amino transferase was correlated negatively to folate intake (r = -0.32, P = 0.024) (n = 50) and positively to homocysteine concentrations (r = 0.30, P = 0.025). Body composition was similar among the 3 genotypic groups. Ferritin was also correlated to ALT concentrations of the entire group (P = 0.009).

CONCLUSION

Our data suggest that folate intake and the MTHFR polymorphism represent a part of the link between antioxidant status and liver disease in obese adolescent girls.

Decreased serum adiponectin: an early event in pediatric nonalcoholic fatty liver disease

OBJECTIVE

To evaluate the relative concentrations of cytokines in pediatric nonalcoholic fatty liver disease (NAFLD).

STUDY DESIGN

Thirty children were evaluated at a fasting morning visit to a pediatric research unit.

RESULTS

Compared with normal-weight children (n = 12) and children who were overweight (n = 11), children who had presumed NAFLD (elevated Alanine aminotransferase [ALT] with negative work-up) (n = 7) had significantly lower mean serum adiponectin levels (P = .004). Adiponectin negatively correlated with body mass index (r = -0.60, P = .001), insulin (r = -0.74, P < .001), glucose (r = -0.52, P = .004), and ALT (r = -0.53, P = .003). There was no difference between normal-weight, obese, and presumed NAFLD subjects in mean serum tumor necrosis factor alpha and interleukin-6 and -8 concentrations nor in tumor necrosis factor alpha and interleukin-8 and -10 levels in an ex vivo lipopolysaccharide-stimulated system.

CONCLUSIONS

Serum adiponectin is reduced in children with elevated ALT, similar to adults. However, children with presumed NAFLD do not have elevated pro-inflammatory cytokine levels. This suggests that depressed adiponectin plays a more proximal role than elevated levels of circulating pro-inflammatory cytokines in the development of NAFLD in children.

Decreased prevalence of nonalcoholic fatty liver disease in black obese children

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is a common cause of pediatric liver disease. Studies suggest decreased prevalence in blacks, females, and younger children. However, the proportion of black subjects in these studies was small, and children under 12 were not included. We propose that abnormal alanine aminotransferase (ALT) is more common in whites than blacks, males than females, and children over 12 compared with younger children in a prospective study.

METHODS

We enrolled 181 consecutive asymptomatic obese children attending general pediatric clinics who denied recent fever or known liver disease. Obesity was defined as body mass index (BMI) z score of greater than 1.64 (95th percentile for age and sex). Elevated ALT was defined as greater than 40 U/L. BMI z score, race, sex, age, and parental obesity were compared using the chi-square test and Fisher's exact test.

RESULTS

The population included 81 males and 100 females, 147 non-Hispanic black, 33 non-Hispanic white, and 1 Hispanic white. Elevated ALT occurred in 14 (8%) subjects. White children were significantly more likely to have abnormal ALT (odds ratio [OR] = 4.0, P < .02). Very obese children (BMI z score >2.3) were more likely to have abnormal ALT compared with mildly obese children (OR = 4.0, P < 0.05). Sex, age, hepatomegaly, acanthosis nigricans, and parental obesity did not significantly predict elevated ALT.

CONCLUSION

Eight percent of asymptomatic, obese children had an elevated ALT suggestive of NAFLD. White and very obese children are more likely to be affected. Sex and age are not good clinical predictors of NAFLD. We suggest that all obese children be screened for NAFLD.

Metabolic, hormonal, oxidative, and inflammatory factors in pediatric obesity-related liver disease

OBJECTIVE

To examine the role of metabolic, hormonal, oxidative, and inflammatory factors in pediatric obesity-related liver disease.

STUDY DESIGN

In 50 obese children (age 7 to 14 years) with (n = 20, group 1) or without (n = 30, group 2) hypertransaminasemia and ultrasonographic liver brightness, we studied insulin resistance (fasting glucose/insulin ratio [FGIR]) and serum levels of leptin, iron, transferrin, ferritin, C-reactive protein (CRP), white blood cell (WBC) count, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, C282Y and H63D mutations, and erythrocytic glutathione peroxidase (GPX) activity.

RESULTS

FGIR (6.7 +/- 4.1 vs 9.2 +/- 5.2; P = .02), serum ferritin (88.8 +/- 36.0 vs 39.9 +/- 24.0 ng/mL; P = .0001), serum CRP (5.4 +/- 6.0 vs 1.1 +/- 1.6 mg/dL; P = 0.004), and GPX (8.4 +/- 0.9 vs 5.0 +/- 0.5 U/g Hb; P = .05) were significantly higher and more frequently deranged in group 1 than in group 2. FGIR, ferritin, and CRP values were simultaneously deranged in 41% of the group 1 patients and in none of the group 2 patients ( P = .098). Serum leptin, iron, and transferrin, WBC, TNF-alpha, IL-6, and C282Y and H63D mutations were similar in the 2 groups.

CONCLUSIONS

Insulin resistance, oxidative stress, and low-grade systemic inflammatory status are implicated in pediatric obesity-related liver disease. These findings may be useful in planning pathophysiologically based therapeutic trials for hepatopathic obese children who are unable to follow hypocaloric diets.

Type 2 diabetes in children is frequently associated with elevated alanine aminotransferase

BACKGROUND

Nonalcoholic fatty liver disease, a cause of chronic liver disease in obese adults also occurs in obese children. In susceptible populations, fatty liver progresses to nonalcoholic steatohepatitis and eventually to fibrosis and cirrhosis. Nonalcoholic steatohepatitis is associated with elevation of alanine aminotransferase, although the aminotransferases can also be normal. The prevalence of nonalcoholic fatty liver disease in type 2 diabetes is unclear in adults and unknown in children.

OBJECTIVES

The aim of this study was to estimate the prevalence of elevated serum aminotransferases as a marker of nonalcoholic fatty liver disease in pediatric type 2 diabetes and to identify correlates of aminotransferase elevation.

METHODS

A chart review was completed on 115 children with type 2 diabetes at a pediatric diabetes clinic. The prevalence of elevated alanine aminotransferase was calculated from the 42% of patients with available aminotransferase measurements and correlations with fasting lipids, hemoglobin A-1c, body mass index, age and diabetes therapy were sought.

RESULTS

The prevalence of elevated alanine aminotransferase was 48%. There was no association between elevations and other variables. Among subjects with elevated alanine aminotransferase, 39% were one to two times above normal, 26% were two to three times normal and 35% were greater than three times above normal. Several patients experienced improvement in aminotransferase elevations after using insulin-sensitizing medications.

CONCLUSIONS

There is a high prevalence of elevated serum aminotransferases among children with type 2 diabetes unrelated to age, body mass index, glycemic control, blood lipids or diabetic therapy. The significance of this abnormality and its relationship to nonalcoholic fatty liver disease requires further evaluation.

Hepatic steatosis in obese Chinese children

OBJECTIVES

THE AIMS OF OUR STUDY WERE

(1) to determine the prevalence of asymptomatic hepatic steatosis and presumed nonalcoholic steatohepatitis, in our local population of obese Chinese children referred for medical assessment; and (2) to assess the correlation between severity of ultrasonographic hepatic steatosis and degree of obesity, insulin resistance and serum biochemical abnormalities.

DESIGN

Cross-sectional study.

METHODS

In total, 84 obese children, 25 girls and 59 boys with median age and body mass index (BMI) of 12.0 years (interquartile range (IR): 9.5-14.0) and 30.3 kg/m(2) (IR: 27.1-33.4), respectively, referred for medical assessment were studied. All subjects underwent physical examination, anthropometric and dual energy X-ray absorptiometry (DEXA) scan measurements and real-time ultrasonographic (US) examination of the liver. Fasting blood samples were collected for the measurement of liver function, hepatitis status, levels of serum glucose and insulin and lipid profile. Degree of fatty infiltration of the liver was graded according to ultrasonic appearance of liver echotexture, liver-diaphragm differentiation in echo amplitude, hepatic echo penetration and clarity of hepatic blood vessels.

RESULTS

All recruited subjects had no history of alcohol abuse and tests for Hepatitis B or C virus were negative. Thorough examination showed all of them to be in general good health without signs of chronic liver disease. Hepatic steatosis identified by defined ultrasonic appearances was diagnosed in 65 subjects (77%); 17 girls and 48 boys. The severity of fatty liver was positively related to anthropometric measurements including BMI, waist and hip circumference, subscapular skinfold thickness; insulin resistance markers [QUICKI and homeostasis model assessment (HOMA)], and hypertriglyceridaemia. Multvariate ordinal regression analysis showed that BMI and raised alanine aminotransferase (ALT) were positively associated with fatty liver. Combination of hepatic steatosis with raised ALT (presumptive NASH) was found in 19 subjects (24%). This group of patients had significantly higher waist hip ratio and conicity index compared to those with isolated hepatic steatosis. Boys with presumed NASH were also found to have significantly higher insulin resistance.

CONCLUSION

Nonalcoholic fatty liver disease (NAFLD) was common among our cohort of obese children referred for medical assessment. The prevalence of simple steatosis and presumed NASH was 77 and 24%, respectively. The severity of US steatosis was positively correlated with BMI, raised ALT, insulin resistance and hypertryglyceridaemia. Ultrasonography being noninvasive and readily available could be used for the monitoring of the progression of hepatic steatosis. Further longitudinal studies are required to determine the natural disease progression and the role of insulin resistance and other factors in the pathophysiology of NAFLD.