Fatty liver and its fibrous changes found in simple obesity of children

Lack of efficacy of ursodeoxycholic acid for the treatment of liver abnormalities in obese children

OBJECTIVE

To determine whether ursodeoxycholic acid (UDCA) is effective for treatment of obesity-related liver abnormalities in children.

STUDY DESIGN

Thirty-one children (21 bboys; mean age, 8.7 years) had obesity-related persistent elevation of aminotransferase levels, which was associated with ultrasonographic images of bright liver in 27. A preliminary interview determined which patients were (n = 18) or were not (n = 13) likely to comply with a balanced low-calorie diet. Four subgroups emerged: patients who followed the diet (n = 11), patients treated with UDCA (10 mg/kg/d) given alone (n = 7) or added to the diet (n = 7), and untreated control patients (n = 6).

RESULTS

Diet alone determined weight loss and resolved biochemical liver abnormalities in all patients. Addition of UDCA to the diet was no more efficacious than weight loss alone. UDCA alone was ineffective for the treatment of liver abnormalities in all cases, and results did not differ from those observed in the untreated control group. Improvement of ultrasonographic abnormalities was observed in patients who lost weight, irrespective of UDCA administration.

CONCLUSIONS

UDCA is not effective for the treatment of obesity-related liver abnormalities in children.

Nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a liver disease that, until recently, has been underrecognized as a common cause of elevated liver enzymes. This distinct clinical entity is characterized by liver biopsy findings similar to those seen in alcoholic hepatitis but in the absence of alcohol consumption sufficient to cause such changes. Patients with NASH are often middle-aged and obese, with coexisting diabetes or hyperlipidemia, but NASH also occurs in younger lean, otherwise healthy individuals and even in children. Although NASH is generally a benign disorder, it may be progressive, leading to cirrhosis and complications of portal hypertension. Liver biopsy remains the gold standard for diagnosis. Therapy for NASH remains poorly defined, although weight reduction and ursodeoxycholic acid may have a beneficial effect.

Liver steatosis in juvenile obesity: correlations with lipid profile, hepatic biochemical parameters and glycemic and insulinemic responses to an oral glucose tolerance test

OBJECTIVE

The aim of this study was to evaluate liver steatosis in prepubertal and pubertal obese and the correlations with the lipid profile, the serum levels of hepatic parameters and the glycemic and insulinemic responses to an oral glucose tolerance test.

SUBJECTS

375 obese, 205 males and 170 females, Tanner pubertal stage I (n=82), stages II-III (n=80) and stages IV-V (n=213).

MEASUREMENTS

Body mass index (BMI), waist-hip ratio (WHR), total cholesterol and high density lipoprotein (HDL), cholesterol/HDL ratio, low density lipoprotein (LDL), very low density lipoprotein (VLDL), triglycerides (TGL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gGT, glycemia (G), insulinemia (IRI), fasting IRI/G ratio (FIGR), glycemic (mean blood glucose, MBG) and insulinemic (mean serum insulin, MSI) responses during a 120 min oral glucose tolerance test (OGTT), expressed as area under the curve (AUC)/120 min, pancreatic insulinemic response to glucose (IRG), and liver ultrasound scanning for assessing the degree of steatosis (moderate, severe).

RESULTS

Liver steatosis was found in 33% of subjects in Tanner pubertal stage I, 36% in stage II-III and 47% in stages IV-V. BMI and transaminases were correlated with the degree of steatosis in all pubertal stages. AST, ALT and gGT were higher in the presence of steatosis, while elevated TGL was present in late puberty only; however the increase of ALT is specific for steatosis.

CONCLUSION

Juvenile obesity involves a high risk of liver steatosis associated with alterations of transaminases and lipid but not glucose metabolism. These changes are apparent even to the prepubertal stage.

Nonalcoholic steatohepatitis in children

BACKGROUND

Nonalcoholic steatohepatitis occurs commonly in adults with obesity or diabetes mellitus. There are only a few reports of this condition in children.

METHODS

Prospective consecutive clinical series.

RESULTS

Between December 1985 and April 1995, 36 children (21 boys, 15 girls) were diagnosed with nonalcoholic steatohepatitis at the Hospital for Sick Children, Toronto. The median age at diagnosis was 12 years (range, 4-16 years). Most patients were referred because of elevated serum aminotransferases or abnormal hepatic sonogram. Thirty patients (83%) were obese. Two patients had diabetes mellitus at diagnosis, and it developed later in two. Fifteen patients had palpable hepatomegaly, and one of these had splenomegaly. None had physical signs of chronic liver disease. Thirteen of 36 patients had acanthosis nigricans. Serum aminotransferases were elevated in all but one patient. Tests for Wilson disease and chronic hepatitis B and C were negative. Serum lipid profiles were abnormal in 18 patients: 7 had hypercholesterolemia, and 11 had hypertriglyceridemia. Twenty-four of 31 examined had abnormal liver sonograms suggestive of fatty infiltration. Twenty-four patients underwent percutaneous liver biopsy: all showed large-droplet fat. Inflammation was present in 88% and fibrosis-cirrhosis in 75%. One 10-year-old patient had established cirrhosis at diagnosis.

CONCLUSIONS

Nonalcoholic steatohepatitis occurs in children, is clinically diverse, and may not be benign.

Childhood obesity

Approximately 10% of children are obese. Twin and adoption studies demonstrate a large genetic component to obesity, especially in adults. However, the increasing prevalence of obesity over the last 20 years can only be explained by environmental factors. In most obese individuals, no measurable differences in metabolism can be detected. Few children engage in regular physical activity. Obese children and adults uniformly underreport the amount of food they eat. Obesity is particularly related to increased consumption of high-fat foods. BMI is a quick and easy way to screen for childhood obesity. Treating childhood obesity relies on positive family support and lifestyle changes involving the whole family. Food preferences are influenced early by parental eating habits, and when developed in childhood, they tend to remain fairly constant into adulthood. Children learn to be active or inactive from their parents. In addition, physical activity (or more commonly, physical inactivity) habits that are established in childhood tend to persist into adulthood. Weight loss is usually followed by changes in appetite and metabolism, predisposing individuals to regain their weight. However, when the right family dynamics exist--a motivated child with supportive parents--long-term success is possible.

Health Consequences of Obesity in Youth: Childhood Predictors of Adult Disease

Obesity now affects one in five children in the United States. Discrimination against overweight children begins early in childhood and becomes progressively institutionalized. Because obese children tend to be taller than their nonoverweight peers, they are apt to be viewed as more mature. The inappropriate expectations that result may have an adverse effect on their socialization. Many of the cardiovascular consequences that characterize adult-onset obesity are preceded by abnormalities that begin in childhood. Hyperlipidemia, hypertension, and abnormal glucose tolerance occur with increased frequency in obese children and adolescents. The relationship of cardiovascular risk factors to visceral fat independent of total body fat remains unclear. Sleep apnea, pseudotumor cerebri, and Blount's disease represent major sources of morbidity for which rapid and sustained weight reduction is essential. Although several periods of increased risk appear in childhood, it is not clear whether obesity with onset early in childhood carries a greater risk of adult morbidity and mortality.

Obesity is now the most prevalent nutritional disease of children and adolescents in the United States. Although obesity-associated morbidities occur more frequently in adults, significant consequences of obesity as well as the antecedents of adult disease occur in obese children and adolescents. In this review, I consider the adverse effects of obesity in children and adolescents and attempt to outline areas for future research. I refer to obesity as a body mass index greater than the 95th percentile for children of the same age and gender.

Nonalcoholic steatohepatitis

NASH is an important form of chronic liver disease that is increasingly recognized. The diagnosis is secured by biopsy findings with similarities to alcoholic hepatitis in a patient with a confirmed history of abstinence. Obesity is a major risk factor, but the disease also occurs in the nonobese. In 20% to 40% of patients the disease can progress to various stages of fibrosis and ultimately cause cirrhosis and death from end-stage liver disease. For this reason, recognition of NASH is important, and establishing the diagnosis provides a further impetus for performing a liver biopsy as part of the evaluation of unexplained liver abnormalities. The mainstay of treatment is weight reduction in the obese. For those individuals who are not obese, continued observation is the only option currently available. Patients who develop decompensated cirrhosis should be considered for liver transplantation unless advanced age or other underlying medical illnesses are a problem. With the increasing knowledge about the pathophysiology of hepatic steatosis, it is hoped that better diagnostic tests for specific causes of NASH will be available and lead to efficacious therapy.

Liver involvement in obese children. Ultrasonography and liver enzyme levels at diagnosis and during follow-up in an Italian population

Our aim was to evaluate incidence and risk factors of liver involvement in obese Italian children as assessed by both ultrasonographic and biochemical parameters. In seventy-five consecutive obese children (age 9.5 +/- 2.9 years, males/females 41/34), serum levels of enzymes and ultrasonography of the liver were evaluated. Tests were repeated one, three, and six months after starting a moderate hypocaloric diet and an exercise program. Three obese children who were found to have chronic viral hepatitis were excluded from the study. Thirty-eight of 72 (53%) obese children had an ultrasonographic image of bright liver consistent with liver steatosis. The latter was severe in nine children, moderate in 16, and mild in 13. Eighteen obese children (25%) had elevated transaminase levels. Bright liver and hypertransaminasemia were not due to any of the most common causes of liver disease. Both were rapidly responsive to loss of weight, confirming that liver involvement was secondary to obesity and that steatosis or steatohepatitis rather than fibrosis were involved. Obesity duration not more than three years (odds ratio = 4.77), a higher degree of obesity (odds ratio = 2.09), and hypertransaminasemia (odds ratio = 2.15) appeared as important predictive factors of liver involvement at ultrasonography. Incidence of liver involvement assessed by means of ultrasonography is significantly higher than that revealed by measurement of serum liver enzymes. A short duration of obesity emerged as a potentially new risk factor of liver involvement in the pediatric obese population and needs to be confirmed in future studies.

Effect of weight changes on serum transaminase activities in obese children

To examine the effect of weight changes on serum transaminase activities, glutamic oxaloacetic and pyruvic transaminases (GOT/GPT), a 3-month observation of 110 obese outpatients treated by a mild regimen for obesity was carried out. Patients were divided into two major groups, group I (n = 73) and group II (n = 37), with or without persistent elevation of serum GOT/GPT (> 30 IU/L), and retrospectively classified into four subgroups according to weight changes: group A, weight loss > 5%; group B, weight loss of < 5%; group C, an increase of < 5%; group D, an increase > 5%. In group IA, the incidence of cases with normalization of serum GOT/GPT was 70% and was significantly greater than those of the other three subgroups, respectively (P < 0.01). The incidences of decreased serum GOT/GPT activities were observed corresponding to the degree of weight changes not only in group I (100-27%) but also in group II (100-33%). These facts indicate that a mild regimen for obese outpatients for 3 months, significantly improves serum transaminase activities in patients not only with weight reduction but also weight gain, and that fatty liver may be present even in obese children with normal serum transaminase levels. The normalization of serum GPT activity in patients with weight gain suggests the presence of another factor contributing hypertransaminasemia in pediatric obese patients.

The relationship between fatty liver and hyperinsulinemia in obese Japanese children

BACKGROUND

Previous reports have revealed that fatty liver involving obesity is closely related to insulin resistance or hyperinsulinemia in adulthood. This study investigates the importance of hyperinsulinemia in obese children with fatty liver.

METHODS

The subjects were 228 obese children 6 to 15 years old in Niigata Prefecture, Japan. The serum level of glutamic pyruvic transaminase (GPT) was evaluated as an indicator of fatty liver. The effects of their percent obesity (percent over ideal body weight), Rohrer index (g/cm3), skinfold thickness, percent body fat measured by bioelectrical impedance analysis, total cholesterol (TC), high-density lipoprotein cholesterol, triglyceride (TG), blood glucose, and immuno-reactive insulin (IRI) on GPT were evaluated using regression analyses.

RESULTS

The incidence of fatty liver (GPT over 35 IU/I) was 24.1% in this study. In simple regression analyses, percent obesity, Rohrer index, skinfold thickness, TC, TG, blood glucose, and IRI correlated positively with GPT (p < 0.05). In stepwise regression analysis including these seven variables, the predictive equation for GPT as a function of IRI alone accounted for 24.2% of the total variance of GPT. The addition of TC alone, and TC and percent obesity together increased the coefficients of determination to 28.4% and 29.9%, respectively. Rohrer index, skinfold thickness, Tg, and blood glucose were not taken as related variables with GPT.

CONCLUSION

Hyperinsulinemia is an important contributor to the development of fatty liver, apparently more than anthropometric data, blood glucose, or serum lipids in childhood obesity.

Serum alanine aminotransferase activity in obese children

To confirm the significance of the serum alanine aminotransferase (ALT) test for the diagnosis of fatty liver and to clarify the relationship between serum ALT activity and the duration of obesity, we analysed 310 obese young school children (195M, 115F), who were classified into three duration groups (1-3 y, 4-6 y, 7 + y), three age groups (6-7 y, 8-9 y, 10-11 y), and four obesity groups (weight excess: mild, 20-29%; moderate, 30-39%; severe, 40-49%; very severe, 50%). Seventy-seven patients with abnormal ALT test, > 30 IU/l, and 27 patients with normal ALT test were examined by ultrasound study to identify the fatty-fibrotic pattern of the liver. Abnormal results of the serum ALT test were found in 24% of all patients. The fatty-fibrotic pattern was identified in 64/77 (83%) patients with abnormal ALT test and in 5/27 (18%) patients with normal ALT test. The serum ALT test has a sensitivity of 0.92 for detecting the fatty-fibrotic pattern proven by ultrasound study. Frequencies of cases with abnormal serum ALT levels increased with the duration of obesity. In the shortest duration group, however, the frequencies of abnormal results in serum ALT test did not increase with advanced ages or the grades of obesity. In conclusion, the present study confirmed the usefulness of the serum ALT test for screening fatty liver, and showed that a longer duration of obesity is generally associated with the occurrence of fatty liver in a paediatric obese population. In young patients with mild obesity or a short duration of obesity, however, fatty liver or fatty fibrosis may develop. Early intervention should be made in the case of obese children.

Nonalcoholic steatohepatitis

NASH is a form of chronic liver disease that is defined by biopsy findings and has the appearance of alcoholic hepatitis. Although this disease was once thought to be a problem of women, diabetics, and the obese, more recent studies have identified a significant proportion of patients who do not fit these risk factors. In a fraction of patients, the disease can progress to various stages of fibrosis leading ultimately to cirrhosis and death from end-stage liver disease. For this reason, recognition of NASH is important and provides a further impetus for performing a liver biopsy as part of the evaluation of unexplained liver biochemical abnormalities. The mainstay of treatment is weight reduction in the obese. For those individuals who are not obese, continued observation is the only available option at this point. With increasing knowledge about the pathophysiology of hepatic steatosis, perhaps more specific diagnostic tests for the cause of the disease in specific patients will be available and will guide appropriate therapy.

Idiopathic steatohepatitis in childhood: a multicenter retrospective study

OBJECTIVE

To describe the clinical, laboratory, and histopathologic features of idiopathic steatohepatitis in children.

STUDY DESIGN

Retrospective review of all liver biopsies performed at Boston Children's Hospital, Massachusetts General Hospital, and the University of Massachusetts Medical Center from 1991 to 1994. Chart review was performed when biopsies demonstrated steatosis.

RESULTS

Eighty-two patients had biopsy-proven hepatic steatosis. Fourteen patients had fatty liver without evidence of inherited, infectious, autoimmune, endocrinologic, toxicologic, or iatrogenic causes. All 14 patients were obese, averaging 159% of ideal body weight (range, 121% to 222%). Nine patients initially had transient abdominal pain, two had hepatomegaly, and one was identified by incidental laboratory evaluation. These 12 patients had biopsies because of persistent elevations of aminotransferase levels. Two other patients without risk factors for steatosis were identified at staging laparotomy for Hodgkin lymphoma. The 10 boys and 4 girls had an average age of 13.5 years (range, 10 to 18 years). Aminotransferase elevations were modest, with aspartate aminotransferase and alanine aminotransferase values averaging 77 +/- 38 IU and 129 +/- 73 IU, respectively. All had imaging studies demonstrating diffuse fatty change. Histologic examination of biopsy specimens revealed varying degrees of steatosis with inflammation and fibrosis.

CONCLUSION

Idiopathic steatohepatitis occurs predominantly or exclusively in obese peripubertal children. This entity represents a frequent reason for liver biopsy in this age group. The degree of steatosis, fibrosis, and inflammation does not correlate with symptoms or signs, and significant liver injury with bridging fibrosis may be present.

The relationship between serum transaminase activities and fatty liver in children with simple obesity

To determine hepatic diseases in obese children, biochemically and histologically, 11 obese patients with abnormal serum transaminase activities were subjected to this study. Fat accumulation in the liver was semiquantitatively graded, and histologically the 11 patients were classified into four groups; fatty liver, fatty hepatitis, fatty fibrosis and fatty cirrhosis. All patients had fat deposition in liver specimens, the grade of which did not significantly correlate with the degree of obesity. The grade of fat deposition in the liver specimens also did not significantly correlate with either serum transaminase activities or GOT/GPT ratio. Five patients were grouped into the fatty liver group, three into the fatty hepatitis group, and the remaining three patients into the fatty fibrosis group. However, no significant differences were found among the three histologically classified groups in terms of serum transaminase activities or GOT/GPT ratio. The usefulness of serum transaminase activities and GOT/GPT ratio was limited in predicting the severity of fat deposition or histological abnormality in pediatric obese patients.

Prevalence of fatty liver in Japanese children and relationship to obesity. An epidemiological ultrasonographic survey

The prevalence of fatty liver in children is unknown and its relationship to obesity is poorly defined. The present study of 810 northern Japanese children (4-12 years old) determined the prevalence of fatty liver in the pediatric population and its relationship to obesity. Diagnosis of fatty liver was based on established real-time ultrasonographic criteria. The overall prevalence of fatty liver was 2.6% and was higher for boys (3.4%) than for girls (1.8%), although not statistically significant (P = 0.15). Fatty liver was found in children as young as 6 years of age. There was no significant association between the prevalence of fatty liver and height (physical growth). There was a strong positive correlation between fatty liver prevalence and established obesity indices: Rohrer's Index--chi 2 linear trend = 59.2, P < 0.0001; body mass index--chi 2 linear trend = 91.6, P < 0.0001; and age-gender-adjusted Japanese standard index of weight for height--chi 2 linear trend = 93.2, P < 0.0001. However, direct measurement of abdominal subcutaneous fat thickness by ultrasonography was the best predictor of fatty liver: chi 2 linear trend = 159, P < 0.0001. These results indicate that fatty liver may develop very early in life, and there is a direct relationship between degree of obesity and fatty liver in children.

Persistent hyperaminotransferasemia resolving after weight reduction in obese children

Nine obese children were referred to our liver disease unit because of asymptomatic, long-standing (range, 4 to 49 months) hyperaminotransferasemia of unknown origin. Ultrasonography showed a "bright" liver in most patients. A hypocaloric diet was prescribed, and the hepatic abnormalities of the complaint patients showed a prompt and persistent improvement that paralleled the loss of excess weight.

Effect of weight reduction on hepatic abnormalities in overweight patients

The effects of weight reduction on hepatic test results and physical findings related to the liver were retrospectively evaluated in 39 overweight patients screened to exclude other factors affecting the liver. An additional 11 overweight patients with primary liver disease were retrospectively evaluated to compare the effect of weight reduction in patients with liver disease with its effect in those without primary liver disease. This study showed that in overweight adults without primary liver disease, a weight reduction of greater than or equal to 10% corrected abnormal hepatic test results, decreased hepatosplenomegaly, and resolved some stigmata of liver disease. In similarly studied overweight patients with primary liver disease, some findings improved, but the changes did not correlate with a greater than or equal to 10% weight loss. Increased alanine aminotransferase activity was the most frequent hepatic enzyme abnormality in this population. For every 1% reduction in body weight, alanine aminotransferase activity improved by 8.1%. After other causes of liver disease are eliminated by clinical and biochemical parameters, weight reduction should be tried for overweight patients with abnormal hepatic test results in the absence of obvious primary liver disease as judged by clinical and biochemical parameters before extensive and expensive studies are undertaken.