Nonalcoholic fatty liver disease and carotid atherosclerosis in children

Body composition phenotypes and carotid intima-media thickness in 11-13-year-old children

Early detection of impairment in vascular structure is an important clinical pursuit. However, it is unknown which measure of body composition best predicts vascular wall changes. We assess the differences in body composition among intima-media thickness (IMT) tertiles and determined which measures of body composition are associated with IMT in 385 children aged 11-13 years (196 girls). In this cross-sectional study, body mass index (BMI), waist circumference (WC), body fat mass (BFM), and trunk fat mass (TFM) from dual-energy radiographic absorptiometry and IMT through high-resolution ultrasonography were collected. Differences in body composition measures among IMT tertiles [low IMT (LIMT), ≤ 0.46 mm; middle IMT, 0.46-0.53 mm; higher IMT (HIMT), ≥0.53 mm] were assessed with ANOVA/ANCOVA after categorization. Regression analysis was used to assess the relationships between body composition and IMT. The groups were similar for sex, age, and maturity (p > 0.05). As compared with LIMT group, subjects with HIMT had higher mean values of BMI, BFM, TFM, and WC (p < 0.05). Significant differences were found for WC even when controlling for BMI (p < 0.05). Combining all subjects, IMT was significantly correlated to BMI, BFM, TFM, and WC (p < 0.05). In multiple regression, WC was the only predictor of IMT (β = 0.22, p < 0.001).

CONCLUSION

Differences exist in body composition variables among IMT tertiles. In the overall model, WC was the only obesity-related predictor of increased IMT in 11-13-year-old children.

Atherosclerosis subclinical and inflammatory markers in obese and nonobese children and adolescents

We conducted a systematic review of intima-media thickness(IMT) and inflammatory markers, compared IMT and identified by meta-analysis related to EMI and inflammatory variables in obese and non-obese children and adolescents. We searched for articles in databases Pubmed, Bireme and Science Direct, during years 2000 to 2010, with the following key words in English: "obesity", "adolescents", "atherosclerosis" and "child ", They were used in two combinations: obesity + adolescents + atherosclerosis + child + obesity and atherosclerosis. We used meta-analysis to compare IMT between obese and non-obese patients. We carefully selected 16 articles for final analysis. There were differences in the thickness of IMT between obese and non-obese patients in 12 studies, confirmed by meta-analysis. Obese patients had concentrations of C-reactive protein higher in 13 articles analyzed (p < 0.05) and lower adiponectin levels in 4 (p < 0.05). In general, obese men had lower concentrations of adiponectin and higher values of IMT and C-reactive protein than non-obese men, showing the relationship between obesity and early inflammatory process. We concluded that there is a relationship of obesity with increased IMT and changes in concentrations of inflammatory markers in this phase.

Association between inflammatory markers and liver fat: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common liver disease. Data is emerging that an independent association between markers of subclinical atherosclerosis and NAFLD exists and it may be considered as an independent predictor of cardiovascular (CV) outcomes. We aim to better characterize the relationship between NAFLD and inflammatory markers in a multi-ethnic cohort by assessing fatty liver on computed tomography (CT) scans.

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) is a longitudinal, population-based study from four ethnic groups free of CV disease at baseline. The inflammatory markers studied include: C-reactive protein (CRP) and interleukin 6 (IL-6). On CT scans liver-to-spleen ratio (LSR: Hounsfield Units (HU) of the liver divided by HU of spleen) of <1 and liver attenuation of <40 HU were used as criteria for fatty liver. Unadjusted and adjusted multivariate linear and logistic regression analysis was performed.

RESULTS

4038 participants amongst 6814 MESA population with visible spleen on the CT scan, available CRP and IL-6 levels and no reported liver cirrhosis were included. The average age was 61 +/- 10 years, 37% Caucasians and 45% were males. Mean CRP and IL-6 were 2.36 mg/dl and 1.37 pg/ml respectively. 696 participants (17%) had LSR of <1 and 253 (6%) had liver attenuation of <40 HU. When using LSR <1 as a continuous variable, the correlation (adjusted odds ratio (OR)) with CRP >2.0 was 0.037 (95% CI: 0.02-0.054) and with IL-6 was 0.014 (95% CI: 0.004-0.023). On the other hand when presence and absence of LSR <1 was considered, higher ORs for association with CRP >2: 1.41 (95% CI: 1.16 to 1.73) and IL6:1.18 (95% CI: 1.05 to 1.31) were found. Similarly, the adjusted association of per unit decrease in liver attenuation with CRP>2 was 1.92 (95% CI: 1.20 to 2.63) while for IL-6 was 1.08 (95% CI: 0.69 to 1.47). When considering presence and absence of liver attenuation <40 HU the OR for CRP >2 was 2.27 (95% CI: 1.62 to 3.16) and for IL-6 was 1.33 (95% CI: 1.13 to 1.58).

CONCLUSION

CRP and IL-6 levels were found to be significantly associated with liver fat assessed on CT scan after adjusting for other risk factors for atherosclerosis.

Developmental origins of nonalcoholic fatty liver disease

Obese pregnant women may transmit their metabolic phenotype to offspring, leading to a cycle of obesity and diabetes over generations. Early childhood obesity predicts nonalcoholic fatty liver disease (NAFLD), the most common chronic human liver disease. The fetus may be vulnerable to steatosis because immature fetal adipose depots are not available to buffer the excess transplacental lipid delivery in maternal obesity. In animal models, in utero high-fat diet exposure results in an increase in the accumulation of liver triglycerides in offspring and increased hepatic oxidative stress and apoptosis, perhaps priming the liver for later development of NAFLD. Innate immune dysfunction and necroinflammatory changes have been observed in postnatal offspring liver of animals born to high-fat-fed dams. Postweaning, livers of offspring exposed to maternal high-fat feeding in utero share pathophysiologic features with human NAFLD, including increased de novo lipogenesis and decreased free fatty acid oxidation. Human studies using magnetic resonance imaging have shown that maternal BMI predicts infant intrahepatocellular lipid storage, as seen in animal models. The generational transfer of NAFLD may occur via epigenetic changes in offspring liver. Transmission of microbiota from mother to infant may impact energy retention and immune function that contribute to a predisposition to NAFLD.

Assessment of atherosclerosis in obese adolescents: positive correlation of mean platelet volume and carotid intima media thickness

AIMS

This study aims to assess the correlation of mean platelet volume (MPV) and common carotid artery (CCA) thickness in a population of obese adolescents.

METHODS

Sixty-eight patients and 23 controls were enrolled. Anthropometric measurements, triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transpeptidase, hemoglobin, white blood cell count, platelet count, MPV and insulin resistance by homeostasis model of assessment of insulin resistance were investigated. Furthermore, CCA thickness was measured by high-resolution ultrasound.

RESULTS

MPV and the left CCA thickness were significantly higher in obese adolescents than the healthy controls. The association between MPV and left CCA was checked by linear regression analysis. MPV explained 19% of the variation in left CCA (P < 0.001). At multiple regression analysis, MPV maintained a positive association with the left CCA thickness (P = 0.002) independently of fatty liver grade, relative weight, total cholesterol and homeostasis model of assessment of insulin resistance.

CONCLUSION

MPV is significantly correlated with CCA thickness in obese adolescents.

Arterial function and structure after a 1-year lifestyle intervention in children with nonalcoholic fatty liver disease

BACKGROUND AND AIMS

Lifestyle modification has been the mainstay of controlling childhood obesity and has proved to be effective in reducing cardiovascular risk factors. However, it is currently unknown whether the subclinical atherosclerotic changes associated with nonalcoholic fatty liver disease (NAFLD) in such population are reversible.

METHODS AND RESULTS

We analyzed changes of brachial flow-mediated dilation (FMD), carotid intima-media thickness (cIMT), clinical, laboratory, and imaging data in 120 obese children with NAFLD, at the end of a 1-year intervention program with diet and physical exercise. The lifestyle intervention led to a significant mean decrease of body mass index (BMI)-standard deviation score (SDS), waist circumference (WC) and fat mass, along with diastolic blood pressure, triglycerides, liver enzymes, insulin, insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR), and high-sensitivity C-reactive protein. At the end of the study, FMD improved (P < 0.0001), while cIMT did not change significantly (P = 0.20). A significant decrease in hepatic fat content as measured by magnetic resonance imaging was also observed. Changes in FMD were inversely associated with changes in BMI-SDS, WC, total cholesterol, non-HDL cholesterol, liver enzymes, HOMA-IR, physical activity, and hepatic fat content. After including in the model all the significant variables as well as age, gender, pubertal status, and baseline FMD values, changes in FMD were significantly and independently associated with changes in WC and total cholesterol.

CONCLUSION

Also in obese children with NAFLD arterial function may be restored by improving metabolic risk factors and reducing visceral adiposity following a 1-year lifestyle intervention.

Relationship between aspartate aminotransferase-to-platelet ratio index and carotid intima-media thickness in obese adolescents with non-alcoholic fatty liver disease

OBJECTIVE

There is increasing evidence for an association between non-alcoholic fatty liver disease (NAFLD) and an increased risk of cardiovascular morbidity and mortality. The aim of this study was to investigate the association between aspartate aminotransferase-to-platelet ratio index (APRI) and carotid intima-media thickness (IMT) in obese adolescents with NAFLD.

METHODS

Seventy-six obese adolescents and 36 lean subjects were enrolled in this cross-sectional single-centre study. The obese subjects were divided into two subgroups based on the presence or absence of fatty liver with high transaminase levels (NAFLD group and non-NAFLD group). Fasting blood samples were assayed for transaminase, glucose, and insulin levels. Insulin resistance was calculated by the homeostasis model assessment (HOMA-IR).

RESULTS

APRI values were higher in both obese groups (NAFLD and non-NAFLD) in comparison with the lean group. The NAFLD group had significantly higher APRI values than the non-NAFLD obese group and the lean group. Carotid IMT was higher in both obese groups (NAFLD and non-NAFLD) in comparison with the lean group. The NAFLD group had significantly higher measurements of carotid IMT than the non-NAFLD group and the lean group. APRI was positively correlated with most of the metabolic parameters (total cholesterol, low-density lipoprotein cholesterol, glucose, insulin, HOMA-IR) and with carotid IMT in the NAFLD obese group.

CONCLUSIONS

This study demonstrated that a significant relationship exists between APRI and carotid IMT in obese adolescents with NAFLD. We suggest that an increased APRI score in obese adolescents with NAFLD can possibly serve to predict a more adverse cardiovascular risk profile.

Dietary fructose in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in adults and children. A number of genetic and environmental factors are known to predispose individuals to NAFLD. Certain dietary sugars, particularly fructose, are suspected to contribute to the development of NAFLD and its progression. The increasing quantity of fructose in the diet comes from sugar additives (most commonly sucrose and high fructose corn syrup) in beverages and processed foods. Substantial links have been demonstrated between increased fructose consumption and obesity, dyslipidemia, and insulin resistance. Growing evidence suggests that fructose contributes to the development and severity of NAFLD. In human studies, fructose is associated with increasing hepatic fat, inflammation, and possibly fibrosis. Whether fructose alone can cause NAFLD or if it serves only as a contributor when consumed excessively in the setting of insulin resistance, positive energy balance, and sedentary lifestyle is unknown. Sufficient evidence exists to support clinical recommendations that fructose intake be limited through decreasing foods and drinks high in added (fructose-containing) sugars.

Intrahepatic fat is increased in the neonatal offspring of obese women with gestational diabetes

OBJECTIVES

To assess precision magnetic resonance imaging in the neonate and determine whether there is an early maternal influence on the pattern of neonatal fat deposition in the offspring of mothers with gestational diabetes mellitus (GDM) and obesity compared with the offspring of normal-weight women.

STUDY DESIGN

A total of 25 neonates born to normal weight mothers (n = 13) and to obese mothers with GDM (n = 12) underwent magnetic resonance imaging for the measurement of subcutaneous and intra-abdominal fat and magnetic resonance spectroscopy for the measurement of intrahepatocellular lipid (IHCL) fat at 1-3 weeks of age.

RESULTS

Infants born to obese/GDM mothers had a mean 68% increase in IHCL compared with infants born to normal-weight mothers. For all infants, IHCL correlated with maternal prepregnancy body mass index but not with subcutaneous adiposity.

CONCLUSION

Deposition of liver fat in the neonate correlates highly with maternal body mass index. This finding may have implications for understanding the developmental origins of childhood nonalcoholic fatty liver disease.

Accuracy of prediction scores and novel biomarkers for predicting nonalcoholic fatty liver disease in obese children

BACKGROUND

Accurate prediction scores for liver steatosis are demanded to enable clinicians to noninvasively screen for nonalcoholic fatty liver disease (NAFLD). Several prediction scores have been developed, however external validation is lacking.

OBJECTIVE

The aim was to determine the diagnostic accuracy of four existing prediction scores in severely obese children, to develop a new prediction score using novel biomarkers and to compare these results to the performance of ultrasonography.

DESIGN AND RESULTS

Liver steatosis was measured using proton magnetic resonance spectroscopy in 119 severely obese children (mean age 14.3 ± 2.1 years, BMI z-score 3.35 ± 0.35). Prevalence of steatosis was 47%. The four existing predictions scores ("NAFLD liver fat score," "fatty liver index," "hepatic steatosis index," and the pediatric prediction score) had only moderate diagnostic accuracy in this cohort (positive predictive value (PPV): 70, 61, 61, 69% and negative predictive value (NPV) 77, 69, 68, 75%, respectively). A new prediction score was built using anthropometry, routine biochemistry and novel biomarkers (leptin, adiponectin, TNF-alpha, IL-6, CK-18, FGF-21, and adiponutrin polymorphisms). The final model included ALT, HOMA, sex, and leptin. This equation (PPV 79% and NPV 80%) did not perform substantially better than the four other equations and did not outperform ultrasonography for excluding NAFLD (NPV 82%).

CONCLUSION

The conclusion is in severely obese children and adolescents existing prediction scores and the tested novel biomarkers have insufficient diagnostic accuracy for diagnosing or excluding NAFLD.

Fatty liver is a good indicator of subclinical atherosclerosis risk in obese children and adolescents regardless of liver enzyme elevation

AIM

To investigate the presence of association between nonalcoholic fatty liver disease (NAFLD) and subclinical atherosclerosis using carotid intima media thickness (c-IMT) in obese children and adolescents. Additionally, we wished to investigate the relationship between fatty liver and elevated liver enzymes.

METHODS

A total of 157 obese patients (78 boys and 79 girls, mean age: 11.3 ± 2.6 years, age range: 6-16 years) were enrolled in the study. Aminotransferase, fasting glucose and lipid levels were determined. An oral glucose tolerance test was performed. The c-IMT was measured. Infectious and metabolic causes of elevated liver enzymes were excluded. The diagnosis of NAFLD was based on ultrasound scan.

RESULTS

Obese patients with NAFLD had markedly increased carotid IMT (mean: 0.48 mm, 95% CI: 0.47-0.49) than those without NAFLD (mean: 0.45 mm 95% CI: 0.44-0.45, p < 0.001). The presence of NAFLD significantly increased c-IMT whether the patient had elevated liver enzyme or not (ANOVA, p < 0.001). In a multiple-regression model, only the presence of NAFLD was associated with increased c-IMT (β = 0.031, SE (β) = 0.008, p < 0.001).

CONCLUSION

Obese children and adolescents with NAFLD are at risk of early atherosclerotic changes. As liver function tests are not sufficient to identify patients with fatty liver, ultrasonographic evaluation of NAFLD might be considered in all obese children and adolescents.

The relationship between pediatric nonalcoholic fatty liver disease and cardiovascular risk factors and increased risk of atherosclerosis in obese children

To investigate the relationship between nonalcoholic fatty liver disease and cardiovascular risk factors and increased risk of atherosclerosis in obese children. The study included 80 consecutive obese children who were stratified into group 1 [ultrasonographically diagnosed with NAFLD (n = 50)] and group 2 [not diagnosed with NAFLD (n = 30)]. The control group included 30 healthy children. The groups were compared in terms of clinical cardiovascular risk factors and carotid intimal medial thickness (CIMT) (as a marker of atherosclerosis) measured using B-mode ultrasound. Mean body mass index (BMI) and blood pressure (BP), as well as the frequency of dyslipidemia, metabolic syndrome (MetS), and insulin resistance (IR), were similar in groups 1 and 2. Mean BMI and triglyceride (TG) levels, and the frequency of IR and MetS, increased significantly as the grade of steatosis increased. Mean CIMT in group 1 was significantly greater than that in the control group (P < 0.01). There was a positive correlation between CIMT and age, BP, and BMI in groups 1 and 2. In addition, CIMT was correlated with TG, low high-density lipoprotein (HDL) cholesterol, MetS, and IR only in group 1. Linear regression analysis between CIMT and age, BP, BMI, TG level, HDL cholesterol level, IR, MetS, and grade of steatosis yielded a significant difference only for grade of steatosis. Cardiovascular risk factors are more impressive and CIMT was significantly higher in group 1 than in group 2 and the control group, indicating that they are associated with greater risk of atherosclerosis and future adverse cardiovascular events.

Genetic determinants of cardiometabolic risk: a proposed model for phenotype association and interaction

This review provides a translational and unifying summary of metabolic syndrome genetics and highlights evidence that genetic studies are starting to unravel and untangle origins of the complex and challenging cluster of disease phenotypes. The associated genes effectively express in the brain, liver, kidney, arterial endothelium, adipocytes, myocytes, and β cells. Progression of syndrome traits has been associated with ectopic lipid accumulation in the arterial wall, visceral adipocytes, myocytes, and liver. Thus, it follows that the genetics of dyslipidemia, obesity, and nonalcoholic fatty liver disease are central in triggering progression of the syndrome to overt expression of disease traits and have become a key focus of interest for early detection and for designing prevention and treatments. To support the "birds' eye view" approach, we provide a road-map depicting commonality and interrelationships between the traits and their genetic and environmental determinants based on known risk factors, metabolic pathways, pharmacologic targets, treatment responses, gene networks, pleiotropy, and association with circadian rhythm. Although only a small portion of the known heritability is accounted for and there is insufficient support for clinical application of gene-based prediction models, there is direction and encouraging progress in a rapidly moving field that is beginning to show clinical relevance.

Evaluation of serum neopterin levels and its relationship with adipokines in pediatric obesity-related nonalcoholic fatty liver disease and healthy adolescents

AIM

Nonalcoholic fatty liver disease (NAFLD) is associated with inflammation and increased risk of atherosclerosis. Neopterin is regarded as a biochemical marker of cell-mediated immunity, which is secreted by monocytes and macrophages, mainly in response to interferon-gamma. The aim of the present study was to investigate the serum neopterin levels in obese adolescents and compare the neopterin levels in patients with and without NAFLD and also with healthy controls. The second aim of the study was to research the possible relationship between neopterin levels and adipokines (leptin, adiponectin, resistin, and ghrelin).

METHODS

Ninety-three obese adolescents (39 with NAFLD, 54 without NAFLD) and 55 healthy controls were enrolled in the study. Serum levels of neopterin and adipokines were measured with high-performance liquid chromatography and sandwich enzyme-linked immunosorbent assay, respectively.

RESULTS

Serum neopterin levels were significantly higher in patients with NAFLD (3.20 ± 0.09 nmol/L) than in their healthy peers (2.91 ± 0.08 nmol/L) (p=0.020). Neopterin levels were positively correlated with leptin levels in obese patients (r=0.380, p<0.001) and in the group comprising all individuals (r=0.206, p<0.05). There was no correlation between neopterin concentrations and relative weight, alanin aminotransferase, adiponectin, resistin, and ghrelin levels.

CONCLUSION

The serum neopterin levels were significantly higher in obese adolescents with fatty liver disease compared to controls, and this may be related to increased cell-mediated immunity in fatty liver disease.

Evaluation of carotid artery stiffness in obese children using ultrasound radiofrequency data technology

OBJECTIVES

The goals of this study were to investigate the difference in carotid arterial stiffness in obese children compared to healthy children and to study the correlation between carotid arterial stiffness parameters and obesity using ultrasound (US) radiofrequency (RF) data technology.

METHODS

Carotid artery stiffness parameters, including the compliance coefficient, stiffness index, and pulse wave velocity, were evaluated in 71 obese patients and 47 healthy controls with US RF data technology. In addition, all participants were evaluated for fat thickness in the paraumbilical abdominal wall and fatty liver using abdominal US.

RESULTS

Compared to the control group, the blood pressure (BP), body mass index (BMI), fat thickness in the paraumbilical abdominal wall, presence of fatty liver, and carotid stiffness parameters (stiffness index and pulse wave velocity) were significantly higher in the obese group, whereas the compliance coefficient was significantly lower in the obese group. Furthermore, the pulse wave velocity was weakly positively correlated with the BMI, systolic BP, diastolic BP, and paraumbilical abdominal wall fat thickness, whereas the compliance coefficient was weakly negatively correlated with the systolic BP, BMI, and paraumbilical abdominal wall fat thickness. The presence of a fatty liver was moderately positively correlated with the BMI and weakly positively correlated with the pulse wave velocity.

CONCLUSIONS

Ultrasound RF data technology may be a sensitive noninvasive method that can be used to accurately and quantitatively detect the difference in carotid artery stiffness in obese children compared to healthy children. The detection of carotid functional abnormalities and nonalcoholic fatty liver disease in obese children should allow early therapeutic intervention, which may prevent or delay the development of atherosclerosis in adulthood.

Association between nonalcoholic fatty liver disease and cardiovascular risk in obese children and adolescents

BACKGROUND

The recent rise in the prevalence of obesity likely explains nonalcoholic fatty liver disease (NAFLD) epidemic worldwide. We evaluated cardiac functions, cardiovascular risk, and associated parameters with grades of NAFLD in obese children.

METHODS

Four hundred obese children were enrolled in the study. Obese children with NAFLD were classified in 2 subgroups according to ultrasonographic visualizing. Ninety-three obese children with NAFLD (mean age 11.73 ± 2.72 years in group 2 and 12.69 ± 2.61 years in group 3) were compared with 307 age- and sex-matched non-NAFLD obese children and 150 control subjects. Laboratory parameters were measured during the fasting state. Pulsed and tissue Doppler echocardiography were performed. Intima-media (IMT) and epicardial adipose tissue (EAT) thicknesses were measured.

RESULTS

NAFLD groups had a significantly higher body mass index (29.15 ± 3.42 and 30.46 ± 4.60; P < 0.001), total adipose tissue mass (37.95 ± 4.46% and 46.57 ± 6.45%; P < 0.001), higher insulin, alanine aminotransferase, and aspartate aminotransferase levels. Increased end-systolic thickness of the interventricular septum (P < 0.001), larger left ventricular mass (P < 0.003) and index (P < 0.003) were found in NAFLD groups. Children with NAFLD had higher Tei index values. Also, carotid artery IMT and EAT thickness were significantly higher in obese children. Waist and hip circumference, total cholesterol level, total adipose tissue mass, and interventricular septum were statistically different in NAFLD groups.

CONCLUSIONS

Children with NAFLD had mildly altered left and right ventricular functions and all obese children had increased IMT and EAT thickness. Also, grade of liver steatosis was positively correlated with total adipose tissue mass and interventricular septum systolic thickness.

Non-alcoholic fatty liver disease and cardiovascular disease: epidemiological, clinical and pathophysiological evidences

Non-alcoholic fatty liver disease is recognized as the most common and emerging chronic liver disease in western countries. The disease has been traditionally interpreted as a possibly progressing condition to liver fibrosis and cirrhosis. However, recently, a large number of publications have demonstrated that people with non-alcoholic fatty liver have an increased chance of developing cardiovascular diseases, which represent the major causes of death in this setting. This association is mainly explained by the atherogenic profile of the metabolic syndrome a condition frequently associated with fatty liver, which may represent its hepatic component. Some studies have also shown an association independent of traditional risk factors or of the clinical features of the metabolic syndrome. In this setting, cardiovascular disease seems to be the consequence of low-grade chronic inflammation and increased oxidative stress. Most studies did not differentiate cardiovascular risk between simple steatosis and non-alcoholic steatohepatitis, although the latter seems to be at higher cardiovascular risk. Few studies have investigated the direct correlation between hepatic inflammation and atherosclerosis. Genetic studies will probably improve the interpretation of the increased cardiovascular risk in patients with fatty liver and no metabolic syndrome.

Relationship between Nonalcoholic Fatty Liver Disease and Carotid Artery Atherosclerosis Beyond Metabolic Disorders in Non-Diabetic Patients

Background

The objective of this study was to investigate the association between nonalcoholic fatty liver disease (NAFLD) and carotid artery atherosclerosis beyond metabolic disorders.

Methods

We studied 320 non-diabetic patients with ultrasonographically diagnosed NAFLD and 313 non-diabetic patients without NAFLD who have less than 40 g alcohol/week drinking history. Carotid atherosclerotic burden was assessed by carotid intima-media thickness (IMT) and plaque. All subjects were divided to the metabolic syndrome (MetS) according to International Diabetes Federation criteria.

Results

NAFLD patients had a significantly increased mean carotid IMT (0.79 ± 0.18 vs. 0.73 ± 0.13 mm; p < 0.001) than those without the condition. The prevalence of increased IMT, defined as IMT ≥ 1 mm, and carotid plaque were 52.5% and 34.1% in the patients with NAFLD vs. 35.8% and 18.8% in the patients without this condition (p < 0.001). The difference in IMT and prevalence of plaque was also significant even in patients without MetS as well as those with MetS (all p < 0.05). NAFLD-associated adjusted odds ratio for increased IMT was 1.236 [95% confidence interval (CI), 1.023-1.467, p = 0.016] without MetS and 1.178 (95% CI, 1.059-1.311, p = 0.003) with MetS. NAFLD-associated adjusted odds ratio of carotid plaque was 1.583 (95% CI, 1.309-1.857, p = 0.024) without MetS and 1.536 (95% CI, 0.512-4.604, p = 0.444) with MetS.

Conclusion

NAFLD is significantly associated with carotid atherosclerosis in non-diabetic outpatients even without MetS. Carotid screening for NAFLD might be beneficial for assessment of future atherosclerotic complications.

Children with NAFLD are more sensitive to the adverse metabolic effects of fructose beverages than children without NAFLD

CONTEXT

Dietary fructose induces unfavorable lipid alterations in animal models and adult studies. Little is known regarding metabolic tolerance of dietary fructose in children.

OBJECTIVES

The aim of the study was to evaluate whether dietary fructose alters plasma lipids in children with nonalcoholic fatty liver disease (NAFLD) and in healthy children.

DESIGN AND SETTING

We performed a 2-d, crossover feeding study at the Inpatient Clinical Interaction Site of the Atlanta Clinical and Translational Science Institute at Emory University Hospital.

PARTICIPANTS AND INTERVENTION

Nine children with NAFLD and 10 matched controls without NAFLD completed the study. We assessed plasma lipid levels over two nonconsecutive, randomly assigned, 24-h periods under isocaloric, isonitrogenous conditions with three macronutrient-balanced, consecutive meals and either: 1) a fructose-sweetened beverage (FB); or 2) a glucose beverage (GB) being consumed with each meal.

MAIN OUTCOME MEASURES

Differences in plasma glucose, insulin, triglyceride, apolipoprotein B, high-density lipoprotein cholesterol, and nonesterified free fatty acid levels were assessed using mixed models and 24-h incremental areas under the time-concentration curve.

RESULTS

After FB, triglyceride incremental area under the curve was higher vs. after GB both in children with NAFLD (P = 0.011) and those without NAFLD (P = 0.027); however, incremental response to FB was greater in children with NAFLD than those without NAFLD (P = 0.019). For all subjects, high-density lipoprotein cholesterol declined in the postprandial and overnight hours with FB, but not with GB (P = 0.0006). Nonesterified fatty acids were not impacted by sugar but were significantly higher in NAFLD.

CONCLUSIONS

The dyslipidemic effect of dietary fructose occurred in both healthy children and those with NAFLD; however, children with NAFLD demonstrated increased sensitivity to the impact of dietary fructose.

Association of liver enzymes with metabolic syndrome and carotid atherosclerosis in young adults. The Cardiovascular Risk in Young Finns Study

OBJECTIVE

We examined whether metabolic syndrome (MetS) predicts increased alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) levels in young adults, whether spontaneous recovery from MetS has a favorable effect on liver enzyme activities, and whether these enzymes contribute to the atherogenicity of MetS (assessed by carotid intima-media thickness (IMT)).

METHODS

The study included 1,553 subjects (base-line age 31.5 ± 5.0 years). ALT and GGT were measured in 2007. MetS was diagnosed by the new Joint Interim Societies definition.

RESULTS

ALT and GGT levels were higher in subjects with MetS compared to those without in 2007. The association was independent of alcohol intake and BMI. In multivariable models adjusted for base-line age, LDL cholesterol, CRP, alcohol intake, and adiponectin, MetS in 2001 predicted increased ALT (β ± SEM = 0.320 ± 0.062, P < 0.0001 in men; 0.134 ± 0.059, P = 0.02 in women) and GGT (β ± SEM = 0.222 ± 0.067, P < 0.0001 in men; 0.236 ± 0.060, P < 0.0001 in women) levels after 6 years. Subjects with MetS only at base-line (2001) had lower ALT levels after 6 years compared to subjects with persistent and incident MetS. No statistically significant interaction for MetS*ALT (P = 0.81) or MetS*GGT (P = 0.92) on IMT was observed.

CONCLUSION

In young adults MetS may induce liver enzyme changes that indicate increased risk of non-alcoholic fatty liver disease, but we found no evidence that increased enzyme levels would amplify the atherogenicity of MetS.

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.

Nonalcoholic fatty liver disease and cardiovascular disease: has the time come for cardiologists to be hepatologists?

Nonalcoholic fatty liver disease (NAFLD) is prevalent in people with the metabolic syndrome and type 2 diabetes and is present in up to one-third of the general population. Evidence is now accumulating that NAFLD is associated with obesity and diabetes and may serve as a predictor of cardiovascular disease (CVD). The possible mechanisms linking NAFLD and CVD include inflammation and oxidative stress, hyperlipidaemia, insulin resistance, and direct impact of NAFLD on coronary arteries and left ventricular dysfunction. In addition, several studies suggest that NAFLD is associated with high risk of CVD and atherosclerosis such as carotid artery wall thickness and lower endothelial flow-mediated vasodilation independently of classical risk factors and components of the metabolic syndrome. It is not yet clear how treatment of NAFLD will modulate the risk of CVD. Furthermore, studies are urgently needed to establish (i) the pathophysiology of CVD with NAFLD and (ii) the benefit of early diagnosis and treatment of CVD in patients with NAFLD. In the absence of biochemical markers, it is crucial that screening and surveillance strategies are adopted in clinical practice in the growing number of patients with NAFLD and at risk of developing CVD. Importantly, the current evidence suggest that statins are safe and effective treatment for CVD in individuals with NAFLD.

Advances in pediatric nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most common cause of pediatric liver disease in the developed world. Children have a form of NAFLD that is pathologically distinct from adults. Although NAFLD remains a pathologic diagnosis, biomarkers and imaging studies hold promise as noninvasive means of both establishing the diagnosis and following the disease course. Significant advancements have recently been made in genetics, pathophysiology, and the treatment of NAFLD. The purpose of this article is to provide a clinically relevant review of pediatric NAFLD with an emphasis on recent developments in the field.

Mechanisms linking nonalcoholic fatty liver disease with coronary artery disease

The most common cause of death in patients with nonalcoholic fatty liver disease (NAFLD) is coronary artery disease (CAD), not chronic liver disease. Fatty liver increases cardiovascular risk by classical (dyslipidemia, hypertension, diabetes) and by less conventional mechanisms. Common pathways involved in the pathogenesis of fatty liver and CAD includes hepatic insulin resistance and sub clinical inflammation. The hepatic insulin resistance state of fatty liver infiltration is characterized by increased FFA, which causes lipotoxicity and impairs endothelium-dependent vasodilatation, increases oxidative stress, and has a cardio toxic effect. Additional metabolic risk factors include leptin, adiponectin, pro inflammatory cytokines [such as IL-6, C-reactive protein and plasminogen activator inhibitor-1 (PAI-1)], which together lead to increased oxidative stress and endothelial dysfunction, finally promoting coronary artery disease (CAD). When classical risk factors are superimposed on fatty liver accumulation, they may further increase the new metabolic risk factors, exacerbating CAD. The clinical implication is that patients with NAFLD are at higher risk (steatohepatitis, diabetes, obesity, atherogenic dyslipidemia) and should undergo periodic cardiovascular risk assessment including the Framingham score, cardiac effort test, and measurement of intimae-media thickening of the carotids arteries. This may improve risk stratification for CAD.

Low 25(OH)D3 levels are associated with total adiposity, metabolic syndrome, and hypertension in Caucasian children and adolescents

OBJECTIVES

Evidence of the association between vitamin D and cardiovascular risk factors in the young is limited. We therefore assessed the relationships between circulating 25-hydroxyvitamin D(3) (25(OH)D(3)) and metabolic syndrome (MetS), its components, and early atherosclerotic changes in 452 (304 overweight/obese and 148 healthy, normal weight) Caucasian children.

METHODS

We determined serum 25(OH)D(3) concentrations in relation to MetS, its components (central obesity, hypertension, low high-density lipoprotein (HDL)-cholesterol, hypertriglyceridemia, glucose impairment, and/or insulin resistance (IR)), and impairment of flow-mediated vasodilatation (FMD) and increased carotid intima-media thickness (cIMT) - two markers of subclinical atherosclerosis.

RESULTS

Higher 25(OH)D(3) was significantly associated with a reduced presence of MetS. Obesity, central obesity, hypertension, hypertriglyceridemia, low HDL-cholesterol, IR, and MetS were all associated with increased odds of having low 25(OH)D(3) levels, after adjustment for age, sex, and Tanner stage. After additional adjustment for SDS-body mass index, elevated blood pressure (BP) and MetS remained significantly associated with low vitamin D status. The adjusted odds ratio (95% confidence interval) for those in the lowest (<17 ng/ml) compared with the highest tertile (>27 ng/ml) of 25(OH)D(3) for hypertension was 1.72 (1.02-2.92), and for MetS, it was 2.30 (1.20-4.40). A similar pattern of association between 25(OH)D(3), high BP, and MetS was observed when models were adjusted for waist circumference. No correlation was found between 25(OH)D(3) concentrations and either FMD or cIMT.

CONCLUSIONS

Low 25(OH)D(3) levels in Caucasian children are inversely related to total adiposity, MetS, and hypertension.

Pediatric nonalcoholic fatty liver disease, metabolic syndrome and cardiovascular risk

Nonalcoholic fatty liver disease (NAFLD) encompasses a range of liver histology severity and outcomes in the absence of chronic alcohol use. The mildest form is simple steatosis in which triglycerides accumulate within hepatocytes. A more advanced form of NAFLD, non-alcoholic steatohepatitis, includes inflammation and liver cell injury, progressive to cryptogenic cirrhosis. NAFLD has become the most common cause of chronic liver disease in children and adolescents. The recent rise in the prevalence rates of overweight and obesity likely explains the NAFLD epidemic worldwide. NAFLD is strongly associated with abdominal obesity, type 2 diabetes, and dyslipidemia, and most patients have evidence of insulin resistance. Thus, NAFLD shares many features of the metabolic syndrome (MetS), a highly atherogenic condition, and this has stimulated interest in the possible role of NAFLD in the development of atherosclerosis. Accumulating evidence suggests that NAFLD is associated with a significantly greater overall mortality than in the general population, as well as with increased prevalence of cardiovascular disease (CVD), independently of classical atherosclerotic risk factors. Yet, several studies including the pediatric population have reported independent associations between NAFLD and impaired flow-mediated vasodilatation and increased carotid artery intimal medial thickness-two reliable markers of subclinical atherosclerosis-after adjusting for cardiovascular risk factors and MetS. Therefore, the rising prevalence of obesity-related MetS and NAFLD in childhood may lead to a parallel increase in adverse cardiovascular outcomes. In children, the cardiovascular system remains plastic and damage-reversible if early and appropriate interventions are established effectively. Therapeutic goals for NAFLD should address nutrition, physical activity, and avoidance of smoking to prevent not only end-stage liver disease but also CVD.

T1-weighted dual-echo MRI for fat quantification in pediatric nonalcoholic fatty liver disease

AIM: To determine in obese children with nonalcoholic fatty liver disease (NAFLD) the accuracy of magnetic resonance imaging (MRI) in assessing liver fat concentration.

METHODS: A case-control study was performed. Cases were 25 obese children with biopsy-proven NAFLD. Controls were 25 obese children matched for age and gender, without NAFLD at ultrasonography and with normal levels of aminotransferases and insulin. Hepatic fat fraction (HFF) by MRI was obtained using a modification of the Dixon method.

RESULTS: HFF ranged from 2% to 44% [mean, 19.0% (95% CI, 15.1-27.4)] in children with NAFLD, while in the controls this value ranged from 0.08% to 4.69% [2.0% (1.3-2.5), P < 0.0001]. HFF was highly correlated with histological steatosis (r = 0.883, P < 0.0001) in the NAFLD children. According to the histological grade of steatosis, the mean HFF was 8.7% (95% CI, 6.0-11.6) for mild, 21.6% (15.3-27.0) for moderate, and 39.7% (34.4-45.0) for severe fatty liver infiltration. With a cutoff of 4.85%, HFF had a sensitivity of 95.8% for the diagnosis of histological steatosis ≥ 5%. All control children had HFF lower than 4.85%; thus, the specificity was 100%. After 12 mo, children with weight loss displayed a significant decrease in HFF.

CONCLUSION: MRI is an accurate methodology for liver fat quantification in pediatric NAFLD.

Atherogenic dyslipidemia and cardiovascular risk in children with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease is now regarded as the most common form of chronic liver disease in adults and children. The close association between nonalcoholic fatty liver disease (NAFLD) and the metabolic syndrome has been extensively described. Moreover, a growing body of evidence suggest that NAFLD by itself confers a substantial cardiovascular risk independent of the other components of the metabolic syndrome. Given the significant potential for morbidity and mortality in these patients, and the large proportion of both pediatric and adult population affected, it is important that we clearly define the overall risk, identify early predictors for cardiovascular disease progression, and establish management strategies. In this article, we will focus on current data linking NAFLD and the severity of liver damage present in children with cardiovascular risk.

Increased intima-media thickness of the carotid artery in childhood: a systematic review of observational studies

Increased carotid intima-media thickness (cIMT) in adults may be caused by a childhood exposure to cardiovascular risk factors. We systematically reviewed observational studies to determine whether obesity, insulin-dependent diabetes mellitus (IDDM), dyslipidemia (DL), hypertension (HT), and chronic renal failure (CRF) are associated with increased cIMT in children and adolescent patients compared with control subjects. We performed a PubMed literature search from January 1986 to February 2010. Two reviewers separately verified the inclusion criteria of relevant studies for the objective of the review. The data extracted in the patient and control groups were sample size, age, gender, cIMT measurement methods, cIMT values, and statistical analysis results. From 348 citations, 65 cross-sectional studies (2 cited twice) with case-control design met the inclusion criteria: 26 in obesity, 14 in IDDM, 11 in DL, 8 in HT, and 8 in CRF. cIMT measurement protocols varied according to the studies, with measurements being performed on the common carotid artery in 65/67 cases and on the far wall in 57/67 cases. From the 67 studies cited, 22/26 reported a significantly increased cIMT in obese children and adolescents compared with the control group, 8/14 in IDDM patients, 10/11 in DL patients, 7/8 in HT patients, and 8/8 in CRF patients.

CONCLUSION

Despite the heterogeneity of ultrasound measurement methods, cIMT was significantly increased in 55 out of the 67 cited studies, confirming early vascular damages in pediatric populations with an increased future risk for vascular diseases.

Increased arterial stiffness and impaired endothelial function in nonalcoholic Fatty liver disease: a pilot study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease both in the general and pediatric population and has been associated with increased cardiovascular risk. Arterial function and early atherosclerotic changes are markers of cardiovascular disease and independent predictors of the corresponding risk. Through a global approach, we investigated the relationships between NAFLD and functional arterial changes and early atherosclerosis.

METHODS

A total of 23 consecutive patients (mean age 55 ± 14 years, 11 males) with biopsy evidence of NAFLD and 28 control subjects matched for age, gender, body mass index, and other cardiovascular risk factors participated in the study.

RESULTS

Compared to controls, NAFLD subjects had significantly higher carotid-femoral pulse wave velocity (PWV; 8.2 ± 1.3 m/s vs. 6.9 ± 1.3 m/s, P = 0.001), higher carotid intima-media thickness (IMT; 0.79 ± 0.18 mm vs. 0.67 ± 0.13 mm, P = 0.01), and reduced flow-mediated dilatation (FMD; 1.92 ± 2.11% vs. 4.8 ± 2.43%, P < 0.001). In multivariable analysis, presence of NAFLD was an independent determinant of both PWV and FMD, whereas leptin was an independent determinant of PWV (B = 0.036, P < 0.05), and adiponectin was independently associated with FMD (B = 0.104, P < 0.05). In addition, histological activity of liver disease expressed by the global Brunt Grade was associated independently with FMD (B = -1.054, P < 0.05).

CONCLUSIONS

NAFLD is associated with arterial stiffness and endothelial dysfunction. Given the important independent prognostic role of these arterial indexes, these findings have important implications for increased cardiovascular risk in patients with NAFLD.

Functional and morphological vascular changes in pediatric nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has been consistently found to be associated with features of the metabolic syndrome (MS), a condition carrying a high risk of cardiovascular events. The present study aimed to determine whether, in children and adolescents, NAFLD is atherogenic beyond its association with MS and its components. We assessed both flow-mediated dilation of the brachial artery (FMD) and carotid intima-media thickness (cIMT), along with lipid profile, glucose, insulin, insulin resistance, and high-sensitivity C-reactive protein (CRPHS), in 250 obese children, 100 with and 150 without NAFLD, and 150 healthy normal-weight children. NAFLD was diagnosed by ultrasound examination and persistently elevated alanine aminotransferase, after exclusion of infectious and metabolic disorders. Compared to controls and children without liver involvement, those with ultrasound-diagnosed NAFLD (and elevated alanine aminotransferase) demonstrated significantly impaired FMD and increased cIMT. Patients with NAFLD had more features of MS and elevated CRPHS levels. In addition, percent FMD was remarkably reduced, whereas cIMT was increased in obese children with MS compared to those without MS. Using logistic regression analysis, the presence of NAFLD was found to be an independent predictor of low percent FMD (odds ratio, 2.25 [95% confidence interval, 1.29 to 3.92]; P = 0.004) as well as of increased cIMT (1.98 [1.16 to 3.36]; P = 0.031), after adjustment for age, gender, Tanner stage, and presence of MS. When we analyzed the relations between cIMT and measures of FMD in patients with NAFLD, the disease was associated with increased cIMT in children with impaired FMD status.

CONCLUSION

The presence of liver disease entails more severe functional and anatomic changes in the arterial wall. Its detection may help identify individuals with increased cardiometabolic risk.

Carotid Intima-media thickness in childhood and adolescent obesity relations to abdominal obesity, high triglyceride level and insulin resistance

AIM

To investigate risk factors which impact on common carotid artery intima media thickness (IMT).

METHODS

A total of 86 obese children and adolescents and 22 healthy children and adolescents with normal weight were enrolled. Moreover, 23 of 86 obese children and adolescents were diagnosed with metabolic syndrome (MetS). The clinical, biochemical data and the IMT of the common carotid artery were measured in all subjects.

RESULTS

Obese and obese with MetS subjects demonstrated a significantly (p < 0.01) thicker intima media (0.69mm, 0.66mm) as compared to the control group (0.38mm), but there was no significant difference of IMT between obese and MetS group. IMT was correlated to body weight, body mass index, waist circumference, waist to hip ratio, systolic blood pressure, diastolic blood pressure, fasting insulin, homoeostasis model assessment-insulin resistance, triglyceride, high-density lipoprotein- cholesterol, low-density lipoprotein-cholesterol, alanine aminotransferase, aspartate aminotransferase and fatty liver. Waist circumference, waist to hip ratio, triglyceride and homoeostasis model assessment-insulin resistance were independent determinants of mean IMT level.

CONCLUSION

Obesity especially abdominal obesity, high TG and insulin resistance may be the main risk predictors of increased IMT.

Mean platelet volume in obese adolescents with nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the accumulation of excess fat in the liver in the absence of alcohol consumption, which commonly coexists with obesity. NAFLD is associated with increased risk of atherosclerosis and insulin resistance. Mean platelet volume (MPV) is a marker of platelet activation, which is a determinant of atherosclerosis.

AIMS

The first aim of the present study was to investigate the MPV levels in obese adolescents and compare the MPV levels in patients with and without NAFLD and also with healthy controls. The second aim of this study was to evaluate the relationship between IR and MPV.

PATIENTS AND METHODS

Case records of 128 exogenous obese adolescents were retrospectively evaluated. Laboratory parameters were collected by using a computerized patient database. Insulin resistance was calculated by a homeostasis model assessment (HOMA-IR) index. Patients were divided into two groups: patients with NAFLD (Group 1) and patients without NAFLD (Group 2). Forty-seven healthy children constituted the control group.

RESULTS

MPV was significantly higher in obese adolescents than their healthy peers. Group 1 had significantly higher MPV than group 2. HOMA-IR was significantly higher in group 1 than group 2. MPV was significantly higher in patients with IR than patients without IR. There was a positive correlation between MPV and HOMA-IR. MPV was inversely correlated with HDL cholesterol and platelet count.

CONCLUSION

MPV may be used as a follow-up marker in patients with NAFLD at the point of atherosclerosis.

Cardiovascular risk factors, nonalcoholic fatty liver disease, and carotid artery intima-media thickness in an adolescent population in southern Italy

The objective of this study was to determine, in an adolescent population, the prevalence of nonalcoholic fatty liver disease (NAFLD) and the association of NAFLD and cardiovascular risk factors with carotid artery intima-media thickness (IMT), a marker of subclinical atherosclerosis. The authors conducted a population-based study among 642 randomly selected adolescents aged 11-13 years in Reggio Calabria, southern Italy, between November 2007 and October 2008. Prevalences of overweight and obesity were 30.5% and 13.5%, respectively. The overall prevalence of NAFLD was 12.5%, increasing to 23.0% in overweight/obese adolescents. In univariate analysis, increased IMT was positively associated with the presence of NAFLD, body mass index (BMI), waist circumference, systolic blood pressure (all P's < 0.001), diastolic blood pressure (P = 0.006), gamma-glutamyl transpeptidase (P = 0.006), alanine aminotransferase (P = 0.007), and C-reactive protein (P = 0.008) and was inversely associated with high density lipoprotein cholesterol (P < 0.001). In multivariate analysis, NAFLD (P = 0.002), BMI (P = 0.004), waist circumference (P = 0.003), and systolic blood pressure (P = 0.005) retained significant associations. The authors conclude that NAFLD, BMI, waist circumference, and systolic blood pressure are independent markers of increased IMT in a random sample of adolescents.

Severity of liver injury and atherogenic lipid profile in children with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. The aim of this study was to assess the relationship between severity of liver injury and atherogenic lipid profile in a large group of children with NAFLD. A total of 118 consecutive children with biopsy-proven NAFLD were included. Patients underwent extensive metabolic profiling. The NAFLD activity and fibrosis scores showed a significant positive correlation with triglyceride/HDL, total cholesterol/HDL, and LDL/HDL ratios (p<0.05) but not with apolipoprotein B/apolipoprotein A-1 ratio (p=0.58). After adjusting for BMI, homeostatic model assessment, impaired glucose tolerance, and presence of metabolic syndrome, both the NAFLD activity score and stage of fibrosis remained independent predictors of proatherogenic lipid profile. All lipid ratios, except for apolipoprotein B/apolipoprotein A-1, were found to be markedly higher in children with nonalcoholic steatohepatitis compared with those with simple steatosis or borderline disease (p<0.05). This study shows for the first time that in children with NAFLD, the severity of liver injury is strongly associated with the presence of a more atherogenic lipid profile, having potential significant diagnostic and therapeutic implications.

Non-alcoholic fatty liver disease: the hepatic consequence of obesity and the metabolic syndrome

Non-alcoholic fatty liver disease (NAFLD) is now the most common liver disease in both adults and children worldwide. As a disease spectrum, NAFLD may progress from simple steatosis to steatohepatitis, advanced fibrosis and cirrhosis. An estimated 20–35% of the general population has steatosis, 10% of whom will develop the more progressive non-alcoholic steatohepatitis associated with markedly increased risk of cardiovascular- and liver-related mortality. Development of NAFLD is strongly linked to components of the metabolic syndrome including obesity, insulin resistance, dyslipidaemia and type 2 diabetes. The recognition that NAFLD is an independent risk factor for CVD is a major public health concern. There is a great need for a sensitive non-invasive test for the early detection and assessment of the stage of NAFLD that could also be used to monitor response to treatment. The cellular and molecular aetiology of NAFLD is multi-factorial; genetic polymorphisms influencing NAFLD have been identified and nutrition is a modifiable environmental factor influencing NAFLD progression. Weight loss through diet and exercise is the primary recommendation in the clinical management of NAFLD. The application of systems biology to the identification of NAFLD biomarkers and factors involved in NAFLD progression is an area of promising research.

Hepatic steatosis, carotid atherosclerosis and metabolic syndrome: the STEATO Study

PURPOSE

Hepatic steatosis is frequently observed in subjects with metabolic syndrome (MS). In type 2 diabetics, it is independently associated with cardiovascular diseases. In order to confirm and extend this finding, a large group of patients with risk factors for atherosclerosis was studied.

METHODS

Carotid atherosclerosis was investigated by echo-Doppler, and hepatic steatosis by ultrasound and transaminase values. Strict exclusion criteria were chosen in order to avoid secondary forms of fatty liver and interference on transaminase values.

RESULTS

Among 970 enrolled patients, about 20% were diabetics, half had MS and 76% presented echographic hepatic steatosis. In multivariate analyses, fatty liver and MS were associated with carotid atherosclerosis [odds ratio (95% confidence intervals) 2.15 (1.27-3.63) and 1.72(1.12-2.64), respectively], whereas HOMA index was not. Aspartate aminotransferase and alanine aminotransferase were not independently associated with carotid atherosclerosis, whereas gamma-glutamyl transferase showed a link with atherosclerosis beyond MS and steatosis presence. The analyses of the 780 non diabetics recruited showed similar results.

CONCLUSIONS

The results of the present study demonstrate that hepatic steatosis measured by echography is associated with carotid atherosclerosis in a large population mostly carrying cardiovascular or metabolic risk factors, independently of MS, cardiovascular diseases, diabetes mellitus and/or insulin resistance.

Vascular health in children and adolescents: effects of obesity and diabetes

The foundations for cardiovascular disease in adults are laid in childhood and accelerated by the presence of comorbid conditions, such as obesity, diabetes, hypertension, and dyslipidemia. Early detection of vascular dysfunction is an important clinical objective to identify those at risk for subsequent cardiovascular morbidity and events, and to initiate behavioral and medical interventions to reduce risk. Typically, cardiovascular screening is recommended for young adults, especially in people with a family history of cardiovascular conditions. Children and adolescents were once considered to be at low risk, but with the growing health concerns related to sedentary lifestyle, poor diet and obesity, cardiovascular screening may be needed earlier so that interventions to improve cardiovascular health can be initiated. This review describes comorbid conditions that increase cardiovascular risk in youth, namely obesity and diabetes, and describes noninvasive methods to objectively detect vascular disease and quantify vascular function and structure through measurements of endothelial function, arterial compliance, and intima-media thickness. Additionally, current strategies directed toward prevention of vascular disease in these populations, including exercise, dietary interventions and pharmacological therapy are described.

Intima-media thickness and liver histology in obese children and adolescents with non-alcoholic fatty liver disease

OBJECTIVE

To evaluate the relationship between biopsy-proven non-alcoholic fatty liver disease (NAFLD) and carotid artery intima-media thickness (CIMT) in children and adolescents.

METHODS

A case-control study was performed. Cases were 31 mostly obese children and adolescents, with NAFLD detected at ultrasonography, and confirmed by liver biopsy. Controls were 49 mostly obese children matched for gender, age and BMI without NAFLD at ultrasonography and with normal levels of aminotransferases. Besides standard laboratory measurements, subjects underwent an oral glucose tolerance test to evaluate glucose tolerance and to estimate whole body insulin sensitivity (ISI).

RESULTS

CIMT was similar in cases and controls on the right side but higher in cases on the left side. Although statistically significant, this difference is unlikely to be clinically relevant because of substantial overlap of CIMT values between cases and controls. Moreover, there was no association between CIMT and the severity of steatosis, ballooning, fibrosis, and the non-alcoholic steato-hepatitis score in cases. At multivariable analysis in the pooled sample (n=80), age and the z-score of BMI but not NAFLD, gender, blood pressure and triglycerides, were associated with CIMT.

CONCLUSIONS

We found no association between CIMT and NAFLD in children and adolescents. More importantly, there was no association between histological severity and CIMT in children with NAFLD.