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.
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.
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.
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.
"Ko et al. reported that 96% of their pediatric patients with NAFLD demonstrated IR (HOMA-IR > 2) (61). Chan et al. showed a positive correlation between IR and male obese children affected by NASH (62). Adipo-IR (FFA × INS) index quantifies Adipose tissue-IR ratio (63). "
[Show abstract][Hide abstract] ABSTRACT: Nonalcoholic Fatty Liver Disease (NAFLD) is the major chronic liver disease in the pediatric population. NAFLD includes a broad spectrum of abnormalities (inflammation, fibrosis and cirrhosis), ranging from accumulation of fat (also known as steatosis) towards non-alcoholic steatohepatitis (NASH). The development of NAFLD in children is significantly increased.
A literature search of electronic databases was undertaken for the major studies published from 1998 to today. The databases searched were: PubMed, EMBASE, Orphanet, Midline and Cochrane Library. We used the key words: "non-alcoholic fatty liver disease, children, non-alcoholic steatohepatitis and fatty liver".
NAFLD/NASH is probably promoted by "multiple parallel hits": environmental and genetic factors, systemic immunological disorders (oxidative stress, persistent-low grade of inflammation) as well as obesity and metabolic alterations (insulin resistance and metabolic syndrome). However its exact cause still underdiagnosed and unknown.
Pediatric NAFLD/NASH is emerging problem. Longitudinal follow-up studies, unfortunately still insufficient, are needed to better understand the natural history and outcome of NAFLD in children. This review focuses on the current knowledge regarding the epidemiology, pathogenesis, environmental, genetic and metabolic factors of disease. The review also highlights the importance of studying the underlying mechanisms of pediatric NAFLD and the need for complete and personalized approach in the management of NAFLD/NASH.
"Secondly, visceral adiposity is related to an accumulation of fat in the liver, a condition known as NAFLD. The result of NAFLD is an excessive release of free fatty acids into the bloodstream (due to increased lipolysis), and an increase in hepatic glucose production, both of which have the effect of exacerbating peripheral insulin resistance and increasing the likelihood of T2DM (32). In NAFLD, hepatic insulin resistance mediates the failure of the insulin-signaling pathway, leading to molecular and cellular changes that result in excess accumulation of triglycerides in the hepatocytes (33). "
[Show abstract][Hide abstract] ABSTRACT: 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.
Conflict of interest:None declared.
Journal of Clinical Research in Pediatric Endocrinology 09/2013; 5(3):182-8. DOI:10.4274/Jcrpe.891
"Radetti et al (40) showed a decreased insulin sensitivity in all of the obese children, but no difference was found in insulin sensitivity between children with or without NAFLD. Chan et al (41) showed a positive correlation between insulin resistance markers and presumed NASH only in male obese children. "
[Show abstract][Hide abstract] ABSTRACT: Objective: Non-alcoholic fatty liver disease (NAFLD) has become one of the most common chronic liver diseases in children. The aim of this study was to investigate the associations of oxidative stress with insulin resistance and metabolic risk factors in obese adolescents with NAFLD.
Methods: Forty-six obese adolescents (23 girls and 23 boys, mean age: 12.8±2.2 years) and 29 control subjects (15 girls and 14 boys, mean age: 12.7±2.7 years) were enrolled in the study. The obese subjects were divided into two groups (NAFLD group and non-NAFLD group) based on the elevated alanine aminotransferase levels (>30 IU/L) and the presence or absence of liver steatosis detected by ultrasonography. Insulin resistance was evaluated by homeostasis model assessment (HOMA-IR) from fasting samples. Plasma total antioxidant status (TAS) and total oxidant status (TOS) level measurements (REL Assay Diagnostics) were done in all participants. The ratio of TOS to TAS was regarded as an oxidative stress index (OSI), an indicator of the degree of OS.
Results: Fasting insulin levels and HOMA-IR values in the NAFLD group were significantly higher than in the non-NAFLD and control groups. TAS measurements were decreased in both obese groups (NAFLD and non-NAFLD) in comparison with the control group. TOS and OSI measurements were higher in the NAFLD group than in the non-NAFLD and control groups. OSI was positively correlated with fasting insulin (r=0.67, p=0.01) and HOMA-IR (r=0.71, p=0.02) in the NAFLD obese group.
Conclusions: In this cross-sectional study, elevated OS markers in obese adolescents with NAFLD were associated with insulin resistance. This data suggest that an antioxidant therapy might have a potential for treating NAFLD associated with insulin resistance.
Conflict of interest:None declared.
Journal of Clinical Research in Pediatric Endocrinology 07/2013; 5(1). DOI:10.4274/Jcrpe.825
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