Gender differences in healthy ranges for serum alanine aminotransferase levels in adolescence

Subnormal Serum Liver Enzyme Levels: A Review of Pathophysiology and Clinical Significance

Subnormal levels of liver enzymes, below the lower limit of normal on local laboratory reports, can be useful diagnostically. For instance, subnormal levels of aminotransferases can be observed in vitamin B6 deficiency and chronic kidney disease. Subnormal alkaline phosphatase levels may indicate the presence of hypophosphatasia, Wilson's disease, deficiencies of divalent ions, or malnutrition. Subnormal levels of gamma glutamyl transferase may be seen in cases of acute intrahepatic cholestasis, the use of certain medications, and in bone disease. Finally, subnormal levels of 5'-nucleotidase have been reported in lead poisoning and nonspherocytic hemolytic anemia. The aim of this review is to bring attention to the fact that subnormal levels of these enzymes should not be ignored as they may indicate pathological conditions and provide a means of early diagnosis.

Age and Sex-Related Differences in Teicoplanine Isoform Concentrations in SARS-CoV-2 Patients

Teicoplanin, a glycopeptide antibiotic commonly used to treat bacterial infections, was discovered to be active in vitro against SARS-CoV-2. The aim of this study was to assess the levels of teicoplanin and its components in a cohort of adult and pediatric SARS-CoV-2 patients, evaluating the effect of sex and age on analyte concentrations. The levels of AST, ALT and leukocytes were shown to be higher in females, while the C reactive protein was higher in males. Evaluating the absence/presence of teicoplanin isoforms, we observed that A2-2_3 is the only one consistently present in pediatrics and adults. In adult men and all pediatrics, A2-4_5 is always present. In pediatrics, except for A3-1, median isoform concentrations were higher in females; on the contrary, in adult patients, males showed higher levels. This is the first study to describe levels of teicoplanin isoforms in SARS-CoV-2 infected patients in males and females, and pediatrics and adults, despite the small sample size of our cohort. The observed results imply that additional testing, via therapeutic drug monitoring, may be helpful to more effectively manage infections, particularly those caused by the most recent viruses.

Effect of Cornus mas L. fruit extract on blood pressure, anthropometric and body composition indices in patients with non-alcoholic fatty liver disease: A double-blind randomized controlled trial

BACKGROUND & AIMS

Obesity is linked to the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Patients with NAFLD are at increased risk for hypertension. Some investigations have hypothesized that Cornus mas L. fruit can improve obesity and hypertension. We investigated the effect of C. mas L. fruit extract on blood pressure, anthropometric and body composition indices in patients with NAFLD.

METHODS

This 12-week double-blind randomized controlled trial was conducted on fifty patients with NAFLD. Patients received 20 cc/d C. mas L. fruit extract or placebo. We measured diastolic blood pressure (DBP), systolic blood pressure (SBP), weight, waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), body fat mass (BFM), body fat percent (BFP) and fat free mass (FFM) before and after intervention.

RESULTS

Treatment group compared to control group showed a significant reduction in DBP (-8.62 ± 11.86 mmHg vs. 0.53 ± 8.53 mmHg; P_crude = 0.003; P_adjucted = 0.03) and SBP (-8.63 ± 14.37 mmHg vs. 0.0 ± 12.67 mmHg; P_crude = 0.02; P_adjucted = 0.02). We found no difference between groups in weight, WC, HC, WHR, BFM, BFP and FFM (P > 0.05). After adjusting for confounding factors, a significant reduction was observed in treatment group compared to control group in BFM (-0.2 ± 3.9 kg vs. 0.7 ± 2.4 kg; P = 0.01) and BFP (-0.2 ± 4.9% vs. 0.8 ± 2.8%; P = 0.02).

CONCLUSIONS

C. mas L. fruit extract statistically reduced blood pressure and body fat. However, it had no effect on other anthropometric and body composition indices. Studies with larger sample sizes and higher dosages of extract are needed.

TRIAL REGISTRATION

Registered on 30/9/2018 at Iranian Registry of Clinical Trials IRCT20180419039359N1 (https://www.irct.ir/trial/30707).

Influence of post-disaster evacuation on childhood obesity and liver dysfunction: The Fukushima Health Management Survey

BACKGROUND

After the Great East Japan Earthquake and subsequent Fukushima Daiichi Nuclear Power Plant accident in 2011, the Fukushima Prefectural Government launched a long-term health management survey for the population of Fukushima. Results of the Comprehensive Health Check (CHC) showed that some children aged 6-15 years, who resided in the evacuation area at the time of the disaster, had obesity, hyperlipidemia, liver dysfunction, and/or renal dysfunction from as early as 2011. The aim of the present study was to determine the long-term trend of obesity and hepatic enzyme abnormalities in Fukushima children.

METHODS

We evaluated the changes in body mass index standard deviation score (BMI-SDS), aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transpeptidase from 2011 to 2018.

RESULTS

Obesity (BMI-SDS ≥ 2) was significantly associated with hepatobiliary enzyme abnormalities. The mean BMI-SDS was significantly higher in 2011 after the disaster, but then soon showed a gradual decrease. The frequency of obesity did not increase significantly after the disaster. There were no significant differences in the prevalence of hepatobiliary enzyme abnormalities in the children aged 6-15 years of either sex from 2011 to 2018.

CONCLUSIONS

In the present study, we found that the increase in the mean BMI-SDS after the disaster was temporary, suggesting that the frequency of obesity and liver dysfunction might not have been significantly influenced by the disaster.

Updated upper limits of normal serum alanine aminotrasferase levels for screening metabolic dysfunction-associated fatty liver disease in obese children

BACKGROUND/PURPOSE

Alanine aminotransferase (ALT) is a cost-effective screening test for asymptomatic liver diseases. The aims of this study are to redefine the ULNs of ALT using the 2010-2012 Nutrition and Health Survey in Taiwan (NAHSIT) database and to determine whether the updated ULNs can better screen for metabolic dysfunction-associated fatty liver disease (MAFLD) in obese children.

METHODS

Reference data were obtained from 2895 NAHSIT participants (1442 boys, 1453 girls) aged 6-18 years. Participants with any of MAFLD-related metabolic risk factors, including overweight/obesity, elevated triglyceride, low high-density lipoprotein cholesterol and high fasting glucose, were excluded. This study compared the sensitivities of different ULNs of ALT for detecting MAFLD in our previously established cohort of obese children.

RESULTS

The ULNs of ALT defined as the 95th percentile in metabolically healthy NAHSIT participants were 23 IU/L for boys and 18 IU/L for girls. When using the updated ULNs, the percentages of elevated ALT levels were 13.0% in boys and 7.8% in girls of all NAHSIT participants. When using the updated ULNs of ALT to detect MAFLD in obese children, the sensitivity was 84.0% in boys and 74.3% in girls. In contrast, when using the conventional ALT cutoff (>40 IU/L), the sensitivity decreased to 61.4% in boys and 36.4% in girls.

CONCLUSION

After taking into account MAFLD-related metabolic risk factors, the ULNs of ALT are 23 IU/L for boys and 18 IU/L for girls in Taiwan. The updated ULNs may be better cutoffs for screening MAFLD in obese children.

Association between serum alanine and aspartate aminotransferase and blood pressure: a cross-sectional study of Chinese freshmen

Background

High blood pressure is a well-recognized risk factor for cardiovascular events, and the incidence of hypertension is increasing among young people. This study investigated the relationship between ALT and AST levels and hypertension among freshmen in China.

Methods

This cross-sectional study was conducted in the Anhui Province from September to November 2018. A total of 3114 freshmen underwent a physical examination including testing of biochemical indicators and a standardized questionnaire.

Results

The overall prevalence of elevated ALT and AST were 6.8% and 2.3% among freshmen. The mean ALT and AST levels were higher in males (22.59 ± 21.98 vs.12.62 ± 10.30 U/L; 23.55 ± 12.24 vs. 20.02 ± 5.75 U/L, respectively). The prevalence of hypertension was significantly higher in men (16.1%) than in women (1.9%). The mean values of BMI, SBP, DBP, TC, TG, and LDL-C were found to be increased with elevated levels of serum ALT and AST in the quartiles (P for trend < 0.05). After adjusting for covariates, the risk of hypertension was significantly higher in the highest ALT quartile than in the lowest quartile (OR (95% CI) of 1.681 (1.028, 2.751) in males; 2.802 (1.102, 7.124) in females). A strong linear relationship was found between serum ALT levels and the odds of hypertension after adjustment for potential confounders only in total population and females (P for trend < 0.05).

Conclusions

These findings suggest that ALT level is significantly associated with hypertension both in male and female freshmen.

Evaluation of liver function tests in the paediatric patient

INTRODUCTION

Although changes in liver function tests can be non-specific in numerous clinical conditions, they can be the first sign of a potentially serious disease in an asymptomatic patient.

MATERIAL AND METHODS

Retrospective cohort study, performed by reviewing the records of children of a reference hospital central laboratory with alanine aminotransferase enzyme (ALT) elevation during a 6-month aleatory period.

RESULTS

572 blood tests with serum ALT elevation corresponding to 403 patients have been assessed during the period studied. 98 patients were excluded for presenting abnormal liver test before the study period of comorbidity that could produce ALT elevation. The remaining 305 patients, 22.6% were diagnosed with a medical condition during the first blood test that explained the ALT elevation, although only 33.3% of them were followed up until verifying their normalisation. Final study sample consists of 236 patients with abnormal liver test without apparent liver disease. Adequate follow-up was found only in 29% of them. From this group, 9 patients (13%) were diagnosed with liver disease. The rest of the samples were not properly monitored. In patients with higher serum ALT levels, follow-up was early and more appropriate.

CONCLUSIONS

In our area, most children without apparent liver disease are no properly monitored. Therefore, an opportunity to diagnosis and treat a potential liver disease was lost in a great number of children. All children with unexplained hypertransaminasaemia must be studied.

Establishment of age- and sex-specific reference intervals for serum liver function tests in pediatric population aged 1-<18 years: A prospective study

Background

The diagnosis, treatment, and prognosis of pediatric diseases rely on the accurate establishment of the reference interval (RI). This study aimed to establish pediatric RIs for liver function tests and evaluated the correlation of the analytes.

Methods

Pediatric population (aged 1–<18 years) was prospectively recruited in Jilin Province, China. Analytes detected by Ortho VITORS 5600 automatic biochemical analyzer. All strata were divided using the regression tree and Harris and Boyd's method. The dynamic changes of RI were evaluated by the lambda‐mu‐sigma method.

Results

Reference individuals were comprised of 6,322 children and adolescents. Age and sex differences were present in all analytes except serum total protein. The serum albumin, total protein, γ‐glutamyl transferase, total bilirubin, and unconjugated bilirubin levels increased with age while serum aspartate aminotransferase was opposite. The serum alanine aminotransferase level reached a trough at the age of 5 and later steadily in males but slowly decreased in females. The serum alkaline phosphatase level dropped rapidly after reaching a peak at 9 years old in females and 12 years old in males. RIs were divided into 11 partitions at most and 5 partitions at least. The strongest correlation between analytes was total bilirubin and unconjugated bilirubin (r = 0.788), followed by total bilirubin and albumin (r = 0.511).

Conclusions

Analytes show unique dynamic changes in pediatric population. The correlations among liver function tests can inform future studies of particular variables. Age‐ and sex‐special pediatric RIs should be established to help an accurate diagnosis of disease.

Serum alanine aminotransferase activity and risk factors for cardiovascular disease in a Caucasian population: the Tromsø study

Background

High and low levels of serum alanine aminotransferase (ALT) are both associated with cardiovascular diseases (CVD) risks especially in elderly, but the mechanisms are less known. This study investigated associations between ALT and CVD risk factors including effects of sex and age in a Caucasian population.

Methods

Cross-sectional data were analysed sex-stratified in 2555 men (mean age 60.4 years) and 2858 women (mean age 60.0 years) from the population study Tromsø 6. Associations were assessed by variance analysis and multivariable logistic regression of odds to have abnormal ALT. Risk factors included body mass index (BMI), waist-to-hip-ratio, blood pressure, lipids, glucose, glycated haemoglobin and high-sensitive C-reactive protein (CRP).

Results

Abnormal elevated ALT was detected in 113 men (4.4%) and 188 women (6.6%). Most CVD risk factors associated positively with ALT in both sexes except systolic blood pressure and CRP (women only), while ALT was positively associated with age in men when adjusted for CVD risk factors, P < 0.001. BMI predicted ALT in men (OR 0.94; 95% CI 0.88–1.00, P = 0.047) and women (OR 0.90; 95% CI 0.86–0.95, P < 0.001). A linear inversed association between age and ALT in men and a non-linear inversed U-trend in women with maximum level between 60 and 64 years were found.

Conclusion

This study confirms a positive relationship between ALT and CVD risk factors, particularly BMI. Age is not a major confounder in the ALT-CVD relationship, but separate sex-analyses is recommended in such studies.

Upper Normal Limits of Serum Alanine Aminotransferase in Healthy Population: A Systematic Review

BACKGROUND

Measuring serum alanine aminotransferase (ALT) enzyme is a routine clinical test commonly used to evaluate abnormalities in the body in general, and in the liver function in particular. Higher ALT levels are associated with some metabolic disorders. The upper limit normal (ULN) is considered as a reliable threshold for the definition of high ALT.

OBJECTIVES:

To assess the existing evidence on the ULN for ALT in the general population.

DATA SOURCE:

PubMed (Medline), EMBASE, Scopus, and Web of Science (ISI) were searched using a specified search strategy.

ELIGIBILITY CRITERIA:

We collected documents published from 1980 to 2018 in the English language, focusing on human samples at the population level and extracted the data after qualitative evaluation.

METHODS

We conducted this study in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement. We used specific search terms and their combinations to find documents from relevant databases. We used a snowballing approach to find documents not captured in the main phase of the search. Two authors separately conducted the search, screened the articles, and selected documents that were qualified for data extraction based on the defined inclusion criteria. Finally, data extraction was conducted by two authors using PRISMA checklist. Reported ULNs for ALT and 95% confidence intervals (CIs) were documented in previously developed datasheets.

RESULTS

Out of 15242 studies, 47 articles were included for data extraction and analysis. Data were sparse and lacked the consistency to precisely estimate ULN for serum ALT. The ULN of ALT was significantly diverse across various geographical locations and sexes. The lowest value of ULN for ALT was 19 IU/L in Chinese children (age range: 7 to < 10 years), and the highest value of ULN for ALT was 55 IU/L in children from Ghana aged < 5 years.

LIMITATIONS:

The main limitation of the current systematic review was the scarcity of the reported measures for ULN of ALT.

CONCLUSION

Based on the results of the current systematic review, it is suggested that the normal range of ALT be redefined, but this redefinition should be done according to the localized data. In order to redefine the ULN for ALT, regional differences, methods used in ALT measurements, and ULN determination should be considered.

Prevalence of Elevated Alanine Aminotransferase by Diagnostic Criterion, Age, and Gender among Adolescents

Background

Serum alanine aminotransferase (ALT) activity was measured not only to detect liver disease, but also to monitor overall health. The purpose of this study was to obtain the prevalence of elevated ALT levels among adolescents.

Methods

In a school-based cross-sectional study, a representative sample was analyzed from 9 middle and high schools in Shenzhen, China, during 2017 to 2018. Elevated ALT was defined as diagnostic criterion I (>30 U/L for boys and >19 U/L for girls) and diagnostic criterion II (>40 U/L).

Results

From the adolescent population, a total of 7281 students (boys, 4014, and girls, 3267) aged from 10 to 17 years were collected. The prevalence of elevated ALT was 7.11% (6.88% for boys and 7.41% for girls) by criterion I and 2.72% (3.96% for boys and 1.19% for girls) by criterion II. Based on the Shenzhen census and Chinese national census population, the adjusted prevalence of elevated ALT was 7.65% (boys 7.19% and girls 8.21%) and 6.79% (boys 6.07% and girls 7.56%) by criterion I and 2.85% (boys 4.20% and girls 1.16%) and 2.43% (boys 3.49% and girls 1.29%) by criterion II. For age, the overall trends were increasing progressively, regardless of the use of diagnostic criteria for an elevated ALT activity.

Conclusions

This study supplements the gap that the prevalence of elevated ALT levels differed in gender, age, and criteria among adolescents of Shenzhen. We should take the prevalence as a predictor and continue to play a warning and preventive role in preparation for further intervention.

Revision of serum ALT upper limits of normal facilitates assessment of mild liver injury in obese children with non-alcoholic fatty liver disease

Background

The serum alanine aminotransferase (ALT) level is a critical parameter for evaluating liver injury in non‐alcoholic fatty liver disease (NAFLD). However, the currently accepted upper limits of normal (ULN) for serum ALT (ULN‐ALT) are debated, as they may be excessively high.

Methods

A total of 1638 children aged 6‐16 years, comprising 507 children with normal BMI (500 healthy children and 7 children with NAFLD), 199 overweight children, and 932 obese children, were included in the analysis. We re‐evaluated the ULN‐ALT in 500 healthy Chinese children using the 95th percentiles of serum ALT levels as revised ULN‐ALT. Fatty liver was identified by ultrasound examination.

Results

Significant positive correlations between serum ALT levels and body mass index (BMI) were detected in overweight boys (r = .399, P < .001), obese boys (r = .398, P < .001), and obese girls (r = .392, P < .001). The prevalence percentages of NAFLD were 93.6%, 75.8%, and 37.9% in obese boys with serum ALT levels of >50, 25‐50, and ≤25 U/L and were 81.6%, 67.9%, and 20.6% in obese girls with serum ALT levels of >40, 20‐40, and ≤20 U/L, respectively.

Conclusion

Serum ALT levels significantly correlated with abnormal BMI values in children, suggesting a rigorous BMI threshold is needed to establish the cutoffs for serum ULN‐ALT in children. Besides, the revised serum ULN‐ALT can uncover mild liver injury in obese children with NAFLD.

Obesity Predicts Liver Function Testing and Abnormal Liver Results

OBJECTIVE

Abnormal liver function tests in children and young people (CYP) predict a greater burden of liver disease in adulthood, especially in the context of obesity. This study aimed to determine whether obesity and metabolic risk factors predict liver function testing and abnormal liver test results in CYP.

METHODS

This was a retrospective cross-sectional population study using electronic health care records from 257,746 CYP aged 10 to 25 years who were registered with 170 contiguous general practices in London, UK. Demographic and clinical data were extracted, including serum alanine aminotransferase (ALT) tests between 2015 and 2017. BMI category thresholds were adjusted according to age group and ethnicity.

RESULTS

Fourteen percent of CYP had ALT measured, of whom 5.4% had abnormal results; 36.3% had BMI indicating overweight or obesity. Nonalcoholic fatty liver disease was the most common liver diagnosis. Multivariate analyses demonstrated that overweight or obesity was an independent predictor of ALT testing in young people (ages 18-25) but not in children (ages 10-17) and of abnormal test results in all CYP, irrespective of ALT threshold.

CONCLUSIONS

Overweight and obesity are predictors of liver testing (not in children) and abnormal test results, irrespective of ALT threshold. Given the rising prevalence of metabolic dysfunction, a coordinated strategy is needed for liver testing and interpreting results in this young population.

Increased liver echogenicity and liver enzymes are associated with extreme obesity, adolescent age and male gender: analysis from the German/Austrian/Swiss obesity registry APV

Background

Childhood obesity is often associated with non-alcoholic fatty liver disease (NAFLD), the most common chronic liver disease in pediatrics.

Methods

This multi-center study analyzed liver echogenicity and liver enzymes in relation to obesity, age, gender and comorbidities. Data were collected using a standardized documentation software (APV) from 1.033 pediatric patients (age: 4–18 years, body mass index = BMI: 28–36 kg/m², 50% boys) with overweight (BMI >90th percentile), obesity (BMI >97th percentile) or extreme obesity (BMI > 99.5th percentile) and obesity related comorbidities, especially NAFLD from 26 centers of Germany, Austria and Switzerland. Liver enzymes aspartate aminotransferase (AST), alanine-aminotransferase (ALT) and gamma glutamyltransferase (gammaGT) were evaluated using 2 cut-off values a) > 25 U/L and b) > 50 U/L. Multiple logistic regression models were used for statistical analysis.

Results

In total, 44% of the patients showed increased liver echogenicity. Liver enzymes > 25 U/L were present in 64% and > 50 U/L in 17%. Increased liver echogenicity was associated with elevated liver enzymes (> 25 U/L: odds ratio (OR) = 1.4, 95% CI: 1.1–1.9, P < 0.02; > 50 U/L: OR = 3.5, 95% CI: 2.4–5.1, P < 0.0001). Extreme obesity, adolescence and male gender were associated with increased liver echogenicity (extreme obesity vs overweight OR = 3.5, 95% CI: 1.9–6.1, P < 0.0001; age > 14 years vs age < 9 years OR = 2.2, 95% CI: 1.4–3.5, P < 0.001; boys vs girls OR = 1.6, 95% CI: 1.2–2.0, P < 0.001) and elevated liver enzymes (extreme obesity vs overweight > 25 U/L: OR = 4.1, 95% CI: 2.4–6.9, P < 0.0001; > 50 U/L: OR = 18.5, 95% CI: 2.5–135, P < 0.0001; age > 14 years vs age < 9 years > 50 U/L: OR = 1.9, 95% CI: 1.0–3.7, P > 0.05; boys vs girls > 25 U/L: OR = 3.1, 95% CI: 2.4–4.1, P < 0.0001; > 50 U/L: OR = 2.1, 95% CI: 1.5–2.9, P < 0.0001). Impaired glucose metabolism showed a significant correlation with elevated liver enzymes > 50 U/L (OR = 4.4, 95% CI: 1.6–11.8, P < 0.005). Arterial hypertension seemed to occur in patients with elevated liver enzymes > 25 U/L (OR 1.6, 95% CI: 1.2–2.0, P < 0.005).

Conclusions

NAFLD is strongly related to extreme obesity in male adolescents. Moreover impaired glucose tolerance was observed in patients with elevated liver enzymes > 50 U/L, but arterial hypertension was only present in patients with moderately elevated liver enzymes > 25 U/L.

Non-alcoholic fatty liver infiltration in children: an underdiagnosed evolving disease

Non-alcoholic fatty liver disease (NAFLD) constitutes the most common liver disease, one that is still underdiagnosed in pediatric populations (as well as in the general population), this due to the progressive increase in childhood obesity observed both in developed and developing countries during the last few decades. The pathophysiology of the disease has not been thoroughly clarified yet. The condition displays common pathways in adults and children; however, there are age-related differences. Unlike adults, children with NAFLD require extensive laboratory analysis, because underlying pathologies other than obesity may contribute to the evolution of the disease. Despite the presence of several serum markers and imaging techniques that contribute to NAFLD diagnosis, liver biopsy remains the gold standard diagnostic procedure. Early intervention and obesity prevention are mandatory, as NAFLD is reversible at an early stage. If left undiagnosed and untreated, NAFLD can progress to steatohepatitis (NASH) and subsequent liver failure, a potentially lethal complication. Of note, there are no treatment options when advanced liver fibrosis occurs. This review summarizes literature data on NAFLD in childhood indicating that this is an evolving disease and a significant component of the metabolic syndrome. Pediatricians should be aware of this entity, screening children at high risk and providing appropriate early management, in collaboration with pediatric subspecialists.

Alanine Aminotransferase and Body Composition in Obese Men and Women

There is a known relationship between serum alanine aminotransferase (ALT) and obesity in humans, but the mechanism(s) are not clarified. This study investigated the associations between serum ALT and body composition in an overweight and obese population. The results are based on data from a previous randomized controlled trial treating obesity with vitamin D₃. A sample of 448 overweight and obese individuals underwent dual-energy X-ray absorptiometry (DEXA) and measured serum ALT along with supplementary blood samples at study baseline. Body fat mass and lean mass indexes were calculated by dividing total body fat/lean weight (kg) by body height squared (kg/m²). ALT correlated with body mass index (BMI) in men but not women (r = 0.33, P < 0.0001 vs. r = 0.06, P = 0.29). In men, serum ALT correlated positively with fat mass index (r = 0.23, P = 0.004) and lean mass index (r = 0.32, P < 0.0001). In women, ALT correlated with lean mass index (r = 0.13, P = 0.031) but not fat mass index (r = 0.003, P = 0.96). In a multivariate model adjusted for age and fat mass index, a 1-unit increase in lean mass index associated with a 0.37 U/L higher ALT in the male subgroup (95% CI 0.024 to 0.040, P < 0.0001). In conclusion, serum ALT was associated with body fat mass index in men and with lean mass index in men and women in an overweight and obese population. The findings also demonstrate a gender difference in the role of fat.

Hepatic enzyme ALT as a marker of glucose abnormality in men with cystic fibrosis

AIM

Cystic fibrosis (CF) patients are at high risk of developing CF-related diabetes (CFRD). In non-CF patients, liver disease, specifically steatosis and non-alcoholic fatty liver disease (NAFLD), is strongly associated with type 2 diabetes. We compared glycemic status and metabolic profiles in CF patients according to a biomarker of hepatic injury, alanine aminotransferase (ALT).

METHODS

We conducted a cross-sectional study among 273 adult CF patients recruited from the Montreal CF Cohort. A 2-hour oral glucose tolerance test (OGTT) was performed to collect glucose and insulin measures every 30 minutes. Fasting ALT levels and anthropometric measures were also obtained. Patients were categorized into 2 groups based on ALT cut-off of 25 U/L.

RESULTS

Patients in the high ALT group were mostly men (83%), had higher mean weight and BMI (p<0.001) and showed elevated glucose levels throughout OGTT (p≤0.01). When stratified by sex, only men with high ALT showed significantly higher weight (p<0.001), higher glycemic values at 60, 90 and 120 minutes of OGTT (p≤0.01), higher frequency of de novo CFRD (20.5% vs 8.2%, p = 0.04) as well as lower insulin sensitivity than men with normal ALT (p = 0.03). ALT levels were strongly associated with HOMA-IR in CFRD patients (p = 0.001, r2 = 0.28).

CONCLUSIONS

Adult CF men with higher ALT show an increased frequency of dysglycemia and de novo CFRD, lower insulin sensitivity and higher eight. Our data suggests that ALT levels could be an interesting tool to guide targeted diabetes screening, particularly among CF men. Prospective studies are needed to confirm these observations.

Clinical significance of low transaminase levels in children with inflammatory bowel disease

BACKGROUND

Low alanine aminotransaminase (LALT) levels may be seen in patients with inflammatory bowel disease (IBD), but there has been no study about the frequency and its clinical significance. We aimed to analyze the frequency of LALT, and its clinical significance in children with IBD.

METHODS

The study included the 89 patients with IBD without hepatobiliary involvement. LALT was defined as ALT levels < 5 U/L. Demographic and clinical findings and outcome of the patients with and without LALT were compared.

RESULTS

LALT was found 47.1% of the patients. At initial examination, it was more common in female patients (92.3 vs. 41.3%, P < 0.001) and patients with CD (57.7 vs. 30.2%, P = 0.01). 75% of the patients with penetrating Crohn's disease (CD) had LALT (P = 0.002). Hemoglobin (10.4 ± 2.1 vs. 11.7 ± 1.9 g/dL, P = 0.01), folic acid (5.2 ± 3.3 vs. 8.6 ± 5.9 ng/mL, P = 0.02) and serum albumin levels (3.6 ± 0.8 vs. 4.7 ± 5 g/dL, P = 0.002) were significantly low in patients with LALT. LALT was associted with the disease relapse within 2 weeks in 12 of the 16 patients with LALT whereas it was seen in 16 of the 73 patients without LALT during the follow-up (75 vs. 21.9%, P < 0.001). Additionally, steroid dependency was more common in patients with LALT during the follow-up (62.5 vs. 12.3%, P < 0.001).

CONCLUSIONS

LALT is common in children with IBD especially in CD and associated with low hemoglobin, albumin and folic acid levels. It may be a marker of relapse and steroid dependency.

Validation of Serum Aminotransferases Levels to Define Severe Dengue Fever in Children

PURPOSE

We aimed to study the pattern of liver-injury in children with dengue fever (DF) and validate serum aminotransferase ≥1,000 IU/L as a marker of severe DF.

METHODS

Children admitted with DF were included. DF was defined by presence of clinical criteria and positive serological or antigen tests in absence of other etiology. DF severity was graded as dengue without or with warning signs and severe dengue. Liver-injury was defined as alanine aminotransferase (ALT) more than twice the upper limit of normal (boys, 30 IU/L; girls, 21 IU/L).

RESULTS

Of 372 children with DF, 144 (38.7%) had liver-injury. Risk of liver-injury and aminotransferase levels increased with DF severity (p<0.001). Recommended ALT and aspartate aminotransferase (AST) cut-off at ≥1,000 IU/L had sensitivity 4.8% (5/105), specificity 99.3% (265/267) for detection of severe DF. In children with ALT and AST <1,000 IU/L (n=365), the area under receiver operating curves for prediction for severe DF, were 0.651 (95% confidence interval [CI], 0.588-0.714; p<0.001) for ALT and 0.647 (95% CI, 0.582-0.712; p<0.001) for AST. Serum ALT at 376 IU/L and AST at 635 IU/L had sensitivity and specificity comparable to ≥1,000 IU/L for defining severe DF.

CONCLUSION

Liver-injury is common in DF. The ALT and AST levels increase with DF severity. ALT and AST levels of ≥1,000 IU/L could be lowered to 376 IU/L and 635 IU/L respectively for defining severe DF.

New pediatric percentiles of liver enzyme serum levels (alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase): Effects of age, sex, body mass index, and pubertal stage

The present study aims to clarify the effects of sex, age, body mass index (BMI), and puberty on transaminase serum levels in children and adolescents and to provide new age- and sex-related percentiles for alanine aminotransferase (ALT), aspartate aminotransferase (AST), and γ-glutamyltransferase (GGT). Venous blood and anthropometric data were collected from 4,126 cases. Excluded were cases of participants with potential hepatotoxic medication, with evidence of potential illness at the time of blood sampling and non-normal BMI (BMI <10th or >90th). The resulting data (N = 3,131 cases) were used for the calculations of ALT, AST, and GGT percentiles. Age- and sex-related reference intervals were established by using an LMS method of Cole-type method. Serum levels of transaminases follow age-specific patterns and relate to the onset of puberty. This observation is more pronounced in girls than in boys. ALT percentiles showed similar-shaped patterns in both sexes. Multivariate regression confirmed significant effects of puberty and BMI-SDS (β = 2.21) on ALT. Surprisingly, AST serum levels were negatively influenced by age (β = -1.42) and BMI-SDS (β = -0.15). GGT percentiles revealed significant sex-specific differences, correlated positively with age (β = 0.37) and showed significant association with BMI-SDS (β = 1.16).

CONCLUSION

Current reference values of ALT, AST, and GGT serum levels were calculated for children between 11 months and 16.0 years, using modern analytical and statistical methods. This study extends the current knowledge about transaminases by revealing influences of age, sex, BMI, and puberty on serum concentrations of all three parameters and has for these parameters one of the largest sample sizes published so far. (Hepatology 2017).

Prevalence and risk factors of elevated alanine aminotransferase among Korean adolescents: 2001-2014

BACKGROUND

An elevated alanine aminotransferase (ALT) level is a surrogate marker of non-alcoholic fatty liver disease (NAFLD), the most common liver disorder in adolescents. The majority of previous NAFLD studies in adolescents were performed in selected obese populations or had a cross-sectional design without a time-trend analysis. The purpose of this study was to estimate the prevalence and time trends of elevated ALT levels in a general adolescent population and to identify factors associated with ALT elevation.

METHODS

We analysed data of adolescent participants (aged 10-18 years) from the Korean National Health and Nutrition Examination Survey 2001-2014, a representative sample of the general population in South Korea. Suspected NAFLD was defined as ALT elevation (> 30 U/L) without hepatitis B surface antigen. In all statistical analyses, sampling weight- and design-based data were used.

RESULTS

ALT was elevated in 5.3% (standard error: 0.3%) of the study population of adolescent participants (N = 8455). No significant trends were found from 2001 to 2014 in the prevalence of elevated ALT among male and female adolescents. In multiple logistic regression analysis, elevated ALT was independently associated with sex (odds ratio [OR] male versus female 4.5; 95% CI, 3.3-6.2), obesity (OR 7.6; 95% CI, 5.3-11.0), and truncal obesity (OR 2.5; 95% CI, 1.8-3.5). Furthermore, male sex, obesity, truncal obesity and high household income level were associated with log-transformed ALT levels in multiple regression analysis.

CONCLUSIONS

In Korean adolescents of both genders, the prevalence of elevated ALT levels was stable from 2001 to 2014. This study has revealed that sex, obesity, truncal obesity and household income level are associated with ALT elevation in adolescents.

Predictive Value of Adiposity Level, Metabolic Syndrome, and Insulin Resistance for the Risk of Nonalcoholic Fatty Liver Disease Diagnosis in Obese Children

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in obese children. Early diagnosis and treatment are essential for curing or slowing down the disease progression. The aim of the study was to assess the prevalence of NAFLD in this population and to identify anthropometrical and metabolic risk factors for NAFLD prediction and its development.

MATERIAL AND METHODS

The study included 108 obese children. Anthropometric measurements, NAFLD diagnosis (based on ALT level and/or liver ultrasound), and metabolic syndrome (MS) components were assessed in all patients. Patients were divided into groups with and without NAFLD.

RESULTS

NAFLD was diagnosed in 49 (45%) patients with similar prevalence in boys (27; 55.10%) and girls [22 (44.9%), p = 0.089]. NAFLD patients had significantly greater waist circumference, WHR, and WHtR and significantly higher total cholesterol, triglyceride, and fasting insulin concentrations as well as higher glucose and insulin concentrations in 120 minutes of OGTT and higher HOMA-IR levels compared to group of patients without NAFLD. In NAFLD patients, MS was significantly more likely to be diagnosed than in group without NAFLD (40.82% versus 22.81%,  p = 0.04), but among the MS components only hypertriglyceridemia was significantly more frequently diagnosed in the group with NAFLD (p = 0.002). Among analysed parameters the best independent risk factor for NAFLD was fasting insulin concentration with the cut-off point = 18,9 uIU/ml (AUC = 0.829).

CONCLUSIONS

NAFLD is a very common disease in obese children. NAFLD predictive risk factors include increased waist circumference, elevated WHR and WHtR, and elevated total cholesterol, triglycerides, and fasting insulin as well as elevated glucose and insulin concentration in the OGTT and HOMA-IR index. NAFLD increases the risk of potential cardiovascular complications expressed by diagnosis of metabolic syndrome. The best independent predictive risk factor for diagnosing NAFLD in obese children is fasting insulin > 18.9 uIU/ml.

Association of Serum 25-hydroxyvitamin D Levels and Liver Enzymes in a Nationally Representative Sample of Iranian Adolescents: The Childhood and Adolescence Surveillance and Prevention of Adult Noncommunicable Disease Study

Background:

Hypovitaminosis D is highly prevalent and has several adverse health effects. This study aims to assess the relationship of serum concentrations of 25-hydroxyvitamin D (25[OH] D) and liver enzymes in adolescents.

Methods:

This population-based cross-sectional survey was conducted among a nationally representative multistage sample of 1095 adolescents (52% boys), aged 10–18 years, living in different provinces of Iran. Serum 25(OH)D concentration <30 ng/mL was considered as hypovitaminosis D, and liver enzymes (alanine aminotransaminase [ALT] and aspartate aminotransaminase [AST]) of >40 U/L was considered as high level. To determine the association between serum 25(OH)D categories and elevated levels of liver enzymes, multiple regression models and linear regression analysis were applied, after adjustment for potential confounders. Odds ratios (95% confidence interval) of serum 25(OH)D and elevated liver enzymes were assessed by logistic regression analysis.

Results:

Higher rates of Vitamin D deficiency were documented among individuals with increased levels of liver enzymes. Compared to boys, median of 25(OH)D was lower in girls with elevated levels of liver function tests (12.75 vs. 25.60 ng/mL for ALT and 13 vs. 14.10 ng/mL for AST), with marginally significant gender differences regarding AST.

Conclusions:

We found a relatively high frequency of hypovitaminosis D among adolescents with abnormal liver function. Further prospective studies are needed to examine these associations from early life.

An assessment of racial differences in the upper limits of normal ALT levels in children and the effect of obesity on elevated values

OBJECTIVES

Childhood obesity is a risk factor for non-alcoholic fatty liver disease and poses important public health issues for children. Racial differences in alanine aminotransferase (ALT) levels among children have not been described. This study aimed to identify racial differences in upper limit normal (ULN) ALT levels and evaluate the effect of obesity on elevated levels in children without other metabolic risk factors.

METHODS

National Health and Nutrition Examination Surveys and clinical data from the Loyola University Health System were used to determine ULN ALT by race and gender. Quantile regression was used to evaluate the impact of obesity on elevated ALT and to identify potential risk factors for ALT above the ULN.

RESULTS

Upper limit normal (ULN) ALT was approximately 28.0 and 21.0-24.0 U/L for boys and girls, respectively. No significant difference in ULN ALT across race was observed. Obesity was significantly associated with elevated ALT; obese children with elevated ALT had values 10 U/L higher than normal-weight children.

CONCLUSIONS

Racial differences in ALT levels among adults are not evident in children. Obesity, in the absence of metabolic risk factors and other causes of liver disease, is associated with elevated ALT, providing evidence against the concept of healthy obesity in children.

Can metabolic function and physical fitness improve without weight loss for inactive, obese, Hispanic adolescents? A feasibility study

INTRODUCTION

A case series that examines the effects of a 12-week combined resistance and aerobic training program for four sedentary obese, Hispanic adolescents without weight loss.

SUBJECTS/METHODS

Baseline and post-intervention anthropometric, metabolic and physical fitness measures were obtained. Body composition, hepatic, visceral, and intramuscular fat contents were analyzed via imaging. Fasting levels of alanine transaminase (ALT), insulin, glucose, free fatty acids, triglycerides, high- and low-density lipoproteins (LDL), and C-reactive protein were obtained via blood samples.

RESULTS

Two subjects decreased their glucose levels by 1.86% and 4.06%. Subjects 1, 3, and 4 increased their lean body mass by 4.12%, 9.70%, and 5.48%. ALT was reduced 13.0%, 16.0%, and 35.7% for subjects 2, 3, and 4, respectively. LDLs were reduced by 37.7%, 4.5%, and 7.5% for subjects 1, 2, and 3. Triglycerides were reduced by 25.4%, 37.8%, and 4.6% for subjects 1, 2, and 3. Visceral fat reductions by 16.5%, 14.2%, and 13.0% occurred for subjects 1, 2, and 3. C-reactive protein was reduced for subjects 1, 2, and 3 by 19.4%, 16.3%, and 32.0%.

CONCLUSION

Expected directions of change were made for most indicators of metabolic function and body composition, but measures of physical fitness improved for all four subjects.

Higher Serum Alanine Transaminase Levels in Male Urokinase-Type Plasminogen Activator-Transgenic Mice Are Associated With Improved Engraftment of Hepatocytes but not Liver Sinusoidal Endothelial Cells

The effects of sex on the degree of liver damage and human cell engraftment were investigated in immunodeficient urokinase-type plasminogen activator-transgenic (uPA-NOG) mice. Liver damage, measured by serum alanine transaminase (ALT) levels, was compared in male and female uPA-NOG mice of different ages. Male mice had significantly higher ALT levels than females with a median of 334 versus 158 U/L in transgenic homozygous mice, respectively. Mice were transplanted with human adult hepatocytes or fetal liver cells and analyzed for any correlation of engraftment of hepatocytes, liver sinusoidal endothelial cells (LSECs), and hematopoietic cells with the degree of liver damage. Hepatocyte engraftment was measured by human albumin levels in the mouse serum. Higher ALT levels correlated with higher hepatocyte engraftment, resulting in albumin levels in male mice that were 9.6 times higher than in females. LSEC and hematopoietic cell engraftment were measured by flow cytometric analysis of the mouse liver and bone marrow. LSEC and hematopoietic engraftment did not differ between male and female transplant recipients. Thus, the sex of uPA-NOG mice affects the degree of liver damage, which is reflected in the levels of human hepatocyte engraftment. However, the high levels of LSEC engraftment observed in uPA-NOG mice are not further improved among male mice, suggesting that a lower threshold of liver damage is sufficient to enhance endothelial cell engraftment. Previously described sex differences in human hematopoietic stem cell engraftment in immunodeficient mice were not observed in this model.

Upper Normal Alanine Aminotransferase Range and Insulin Resistance in Korean Adolescents: Korean National Health and Nutrition Examination Survey, 2009-2010

BACKGROUND

Alanine aminotransferase (ALT) has been one of the most useful biomarkers reflecting liver damage. Some studies have proposed that serum ALT levels, even those within the conventional normal range, are associated with metabolic syndrome and fatty liver.

AIMS

We examined the correlation between ALT levels and insulin resistance (IR) and ALT cutoff value for high IR status in Korean adolescents.

METHODS

A total of 886 subjects (461 boys and 425 girls) who participated in the 2009-2010 Korea National Health and Nutrition Examination Survey were included in this study. Multivariable adjusted logistic regression analyses were used to examine the odds ratios and 95 % confidence intervals (CIs) of the prevalence of the highest quartile of the homeostasis model assessment of IR (HOMA-IR) according to the ALT quartile. The cutoff value of ALT for the highest HOMA-IR quartile (Q4) were obtained using receiver operating characteristic curve analysis.

RESULTS

The mean ALT value increased as the number of metabolic syndrome components increased, but in only boys (p for trend <0.001), while the IR quartile increased in both boys and girls (all p for trends <0.001). The prevalence of IR (Q4) was only increased in ALT (Q4) in boys after the adjustment for age, body mass index, and waist circumference (OR 2.49; 95 % CI 1.05-5.91; p for trend = 0.017). The cutoff values were 17.0 IU/L in boys and 11.0 IU/L in girls.

CONCLUSIONS

The highest ALT quartile was associated with an increased prevalence of the highest quartile of IR in boys but not in girls.

A clinically relevant method to screen for hepatic steatosis in overweight adolescents: a cross sectional study

Background

To develop a screening algorithm to detect hepatic steatosis in overweight and obese adolescents.

Methods

We performed a cross sectional study of 129 overweight adolescents 13–18 yrs. The primary outcome, hepatic steatosis was defined as an intracellular triglyceride content > 5.5 mg/g and quantified using ¹H-magenetic resonance spectroscopy. Primary predictor variables included, alanine and aspartate transaminases (ALT/AST) and features of the metabolic syndrome.

Results

Hepatic steatosis was present in 33 % of overweight and obese adolescents. Adolescents with hepatic steatosis were more likely to be boys (adjusted OR: 4.8; 95 % CI: 2.5–10.5), display a higher waist circumference (111 ± 12 vs 100 ± 13 cm, p < 0.001) and have metabolic syndrome (adjusted OR: 5.1; 95 % CI: 1.6–16.4). Serum ALT predicted hepatic steatosis in boys (AUC: 0.82; 95 % CI: 0.70–0.95; p < 0.001) but not girls (AUC = 0.63; 95 % CI: 0.46–0.75, p = 0.16). An ALT >20 U/L, combined with the presence of metabolic syndrome, male gender and an elevated waist circumference provided the best model (AUC 0.85) with high sensitivity (72 %) and specificity (82 %) and positive and negative predictive values of 61 % and 89 % respectively.

Conclusions

Serum transaminases provide modest predictive value for hepatic steatosis in youth. The ALT threshold for predicting hepatic steatosis is significantly lower than current clinical thresholds for predicting non-alcoholic fatty liver disease. The addition of ALT, presence of the metabolic syndrome and male gender significant improve the ability to predict hepatic steatosis.

Alanine transferase: An independent indicator of adiposity related comorbidity risk in youth

BACKGROUND

Elevated levels of alanine aminotransferase (ALT) are associated with obesity and are often a consequence of non-alcoholic fatty liver disease (NAFLD). The aim of the present study was to assess the relationship between ALT and risk factors for adiposity-related co-morbidities in a diverse population of middle school children.

METHODS

We measured height, weight, body fatness (bioelectrical impedance), waist circumference, insulin sensitivity, phase 1 insulin release (acute insulin response following intravenous glucose), beta-cell function (acute insulin response corrected for insulin sensitivity), ALT, lipid profiles, and circulating concentrations of interleukin-6 (IL-6), C-reactive protein, adiponectin, and tumor necrosis factor-α (TNF-α) in a multi-ethnic/racial population of 106 middle school students (aged 11-14 years, 45 female) of varying body mass indexes (BMI).

RESULTS

Alanine aminotransferase was significantly correlated with BMI, % body fat, fat mass, waist circumference, fasting insulin, insulin resistance, triglycerides, and was inversely correlated with high-density lipoprotein cholesterol in children, even though all values of ALT were "normal" (range of 4.0-33.0 U/L). ALT was significantly higher in males than females even when corrected for body fatness. Significant correlations with lipids and insulin resistance persisted even when adjusted for age, gender, and body fatness.

CONCLUSION

Even within the normative range, ALT levels were significantly correlated with anthropomorphic and biochemical risk factors for adiposity-related co-morbidities in youth. Therefore, because ALT is correlated with dyslipidemia, insulin resistance, and central fat distribution, it might also serve as a marker of risk for adiposity-related co-morbidities beyond NAFLD.

Sex influenced association of directly measured insulin sensitivity and serum transaminase levels: Why alanine aminotransferase only predicts cardiovascular risk in men?

Background

Non alcoholic fatty liver disease (NAFLD) is an independent cardiovascular (CV) risk factor which is closely associated with insulin resistance measured by both direct or indirect methods. Gender specific findings in the relationship between alanine aminotransferase (ALT) and CV disease, the prevalence of NAFLD and type 2 diabetes (T2DM) have been published recently.

The aim of the present study was to explore the gender aspects of the association between insulin sensitivity, liver markers and other metabolic biomarkers in order to elucidate the background behind the sex influenced difference in both NAFLD, T2DM and their association with CV risk.

Patients and methods

158 female (47 normal and 111 impaired glucose intolerant) and 148 male (74 normal and 74 impaired glucose tolerant) subjects were included (mean age: 46.5 ± 8.31 vs. 41.6 ± 11.3, average Hba1c < 6.1 %, i.e. prediabetic population, drug naive at the time of the study). Subjects underwent a hyperinsulinemic normoglycemic clamp to determine muscle glucose uptake (M₃), besides liver function tests and other fasting metabolic and anthropometric parameters were determined.

Results

Significant bivariate correlations were found between clamp measured M₃ and all three liver enzymes (ALT, aspartate aminotransferase and gamma-glutamyl transferase) in both sexes. When data were adjusted for possible metabolic confounding factors correlations ceased in the male population but stayed significant in the female group. Feature selection analysis showed that ALT is an important attribute for M₃ in the female but not in male group (mean Z: 3.85 vs. 0.107). Multiple regression analysis confirmed that BMI (p < 0.0001) and ALT (p = 0.00991) significantly and independently predicted clamp measured muscle glucose uptake in women (R² = 0.5259), while in men serum fasting insulin (p = 0.0210) and leptin levels (p = 0.0294) but none of the liver enzymes were confirmed as significant independent predictors of M₃ (R² = 0.4989).

Conclusion

There is a gender specific association between insulin sensitivity, metabolic risk factors and liver transaminase levels. This might explain the sex difference in the predictive role of ALT elevation for CV disease. Moreover, ALT may be used as a simple diagnostic tool to identify insulin resistant subjects only in the female population according to our results.

Redefining the alanine aminotransferase upper limit of normal improves the prediction of metabolic syndrome risk

BACKGROUND

Multiple studies have recently proposed the lowering of upper limit of normal (ULN) for alanine aminotransferase (ALT) to improve the diagnostic sensitivity for viral hepatitides and metabolic syndrome (MS). We have tried to validate some of the proposed ULNs in the diagnosis of MS.

METHODS

We used data from the HepaMeta Study conducted in 2011 in Slovakia, which explored the prevalence of MS in eastern Slovakia. Patients were tested for the criteria of MS and ALT. Different, previously published, ALT cutoffs were then used to calculate odds' ratios, sensitivity, specificity, and accuracy of MS and its components.

RESULTS

Manufacturers' recommended ULN used in our institution (0.8 µkat/l, 47 U/l for men and 0.6 µkat/l, 35 U/l for women) failed to predict any significant risk of MS. Lowered cutoff (72% of the original ULN) identified the patients with the highest age-adjusted probability of MS (odds ratio 3.194, 95% confidence interval 1.398-7.295). ALT was significantly associated with elevated levels of triacylglycerols, hyperglycemia, and obesity.

CONCLUSION

In patients with MS, one must consider liver involvement if the patient has ALT levels in the upper third of the reference range. There is the need for discussion about the feasibility of lower ALT ULN in clinical practice.

Elevated alanine aminotransferase activity is not associated with dyslipidemias, but related to insulin resistance and higher disease grades in non-diabetic non-alcoholic fatty liver disease

OBJECTIVE

To explore demographic and metabolic factors associated with increased alanine aminotransferase (ALT) activity in non-diabetic non-alcoholic fatty liver disease (NAFLD) patients.

METHODS

Overall 372 patients who consecutively attended to Gastroenterology Clinic of Baqiyatallah University of Medical Sciences, Tehran, Iran awere diagnosed as NAFLD entered into analysis. Exclusion criteria were having diabetes mellitus and fasting blood glucose over 126 mg/dL, active hepatitis B virus infection, having hepatitis C virus positive serology, and to be under corticosteroid therapy. ALT levels were considered pathologically high when it was over 30 IU/L for men and over 19 IU/L for women.

RESULTS

Bivariate analyses using t test and chi-square test showed that patients with pathologically augmented ALT levels had significantly higher NAFLD grades in their ultrasonographic evaluations (P=0.003). Moreover, these patients represented significantly higher homeostatic model assessment levels (P=0.003), levels of serum insulin (P=0.002), fasting blood glucose (P<0.001), and uric acid (P=0.02). The prevalence of insulin resistance was also higher in patients with increased serum ALT concentrations. Multifactorial logistic regression models showed that ultrasonographic grading of NAFLD (P=0.027) and insulin resistance (P=0.013) were the only variables significantly associated with abnormal ALT levels.

CONCLUSIONS

This study shows that the associations of increased ALT serum levels in NAFLD patients are different from what are supposed before. By excluding diabetic patients from our population, we find that increased ALT levels are not associated with dyslipidemias but are independently associated with insulin resistance and NAFLD grading on ultrasonographic evaluations. Further studies are needed to confirm our results.

Screening for elevated risk of liver disease in preschool children (aged 2-5 years) being seen for obesity management

Objectives:

Elevated alanine aminotransferase can heighten concern for the presence of nonalcoholic fatty liver disease in obese children. Guidelines recommend alanine aminotransferase screening of obese children start at the age of 10 years. We examined alanine aminotransferase values routinely obtained for tertiary obesity care among preschool (2–5 years) and school-age children.

Methods:

Medical records of children attending a tertiary obesity clinic and with alanine aminotransferase measured within 6 months of the initial visit were reviewed. Children with known genetic abnormalities were excluded. Children were grouped by age to focus attention on groups not covered by screening guidelines. Associations with elevated alanine aminotransferase (>30 IU/L) were examined.

Results:

A total of 284 records were analyzed (73 preschool, 143 young school-age (6–9 years), 68 older school-age (10–11 years)). Children were primarily Hispanic and had body mass index ≥ 99th percentile (preschool children 92%, young school-age 73%, older school-age 59%). In all, 26% of preschool children had elevated alanine aminotransferase (young school-age 30%, older school-age 44%). Preschool children with elevated alanine aminotransferase had higher body mass index compared to preschool children with alanine aminotransferase ≤ 30 IU/L (median body mass index 27.8 kg/m² vs 24.0 kg/m²; Mann–Whitney U test, p = 0.003), but there was no disparity for elevated alanine aminotransferase related to Hispanic ethnicity. For older children, Hispanic ethnicity, not body mass index, predicted elevated alanine aminotransferase.

Conclusion:

Alanine aminotransferase elevation was common in these preschool children. Screening severely obese children for elevated alanine aminotransferase should begin at the age of 2 years.

Pediatric fatty liver disease: Role of ethnicity and genetics

Non-alcoholic fatty liver disease (NAFLD) comprehends a wide range of conditions, encompassing from fatty liver or steatohepatitis with or without fibrosis, to cirrhosis and its complications. NAFLD has become the most common form of liver disease in childhood as its prevalence has more than doubled over the past 20 years, paralleling the increased prevalence of childhood obesity. It currently affects between 3% and 11% of the pediatric population reaching the rate of 46% among overweight and obese children and adolescents. The prevalence of hepatic steatosis varies among different ethnic groups. The ethnic group with the highest prevalence is the Hispanic one followed by the Caucasian and the African-American. This evidence suggests that there is a strong genetic background in the predisposition to fatty liver. In fact, since 2008 several common gene variants have been implicated in the pathogenesis of fatty liver disease. The most important is probably the patatin like phospholipase containing domain 3 gene (PNPLA3) discovered by the Hobbs’ group in 2008. This article reviews the current knowledge regarding the role of ethnicity and genetics in pathogenesis of pediatric fatty liver.

Pediatric non-alcoholic fatty liver disease: New insights and future directions

One of the most common complications of childhood obesity is the non-alcoholic fatty liver disease (NAFLD), which is the most common form of liver disease in children. NAFLD is defined by hepatic fat infiltration > 5% hepatocytes, as assessed by liver biopsy, in the absence of excessive alcohol intake, viral, autoimmune and drug-induced liver disease. It encompasses a wide spectrum of liver diseases ranging from simple steatosis to non-alcoholic steatohepatitis, which, in turn, can evolve into cirrhosis and end stage liver disease. Obesity and insulin resistance are the main risk factors for pediatric NAFLD. In fact, NAFLD is strongly associated with the clinical features of insulin resistance especially the metabolic syndrome, prediabetes and type 2 diabetes mellitus (T2D). In particular, it has been clearly shown in obese youth that the prevalence of metabolic syndrome, pre-diabetes and type 2 diabetes increases with NAFLD severity progression. Evidence that not all of the obese patients develop NAFLD suggests that the disease progression is likely to depend on complex interplay between environmental factors and genetic predisposition. Recently, a non-synonymous SNP (rs738409), characterized by a C to G substitution encoding an isoleucine to methionine substitution at the amino acid position 148 in the patatin like phospholipase containing domain 3 gene (PNPLA3), has been associated with hepatic steatosis in a multiethnic cohort of adults as well as in children. Another important polymorphisms that acts with PNPLA3 to convey susceptibility to fatty liver in obese youths is the rs1260326 polymorphism in the glucokinase regulatory protein. The pharmacological approach in NAFLD children poorly adherent to or being unresponsive/partially responsive to lifestyle changes, is aimed at acting upon specific targets involved in the pathogenesis. There are some therapeutic approaches that are being studied in children. This article reviews the current knowledge regarding the pediatric fatty liver disease, the new insights and the future directions.

Nonalcoholic fatty liver disease and bariatric surgery in adolescents

Obesity is a multi-organ system disease with underlying insulin resistance and systemic chronic inflammation. Nonalcoholic fatty liver disease (NAFLD) is a hepatic manifestation of the underlying metabolic dysfunction. This review provides a highlight of the current understanding of NAFLD pathogenesis and disease characteristics, with updates on the challenges of NAFLD management in obese and severely obese (SO) patients and recommendations for the pediatric surgeons' role in the care of SO adolescents.

Alanine aminotransferase-old biomarker and new concept: a review

Measurement of serum alanine aminotransferase (ALT) is a common, readily available, and inexpensive laboratory assay in clinical practice. ALT activity is not only measured to detect liver disease, but also to monitor overall health. ALT activity is influenced by various factors, including viral hepatitis, alcohol consumption, and medication. Recently, the impact of metabolic abnormalities on ALT variation has raised concern due to the worldwide obesity epidemic. The normal ranges for ALT have been updated and validated considering the metabolic covariates in the various ethnic districts. The interaction between metabolic and demographic factors on ALT variation has also been discussed in previous studies. In addition, an extremely low ALT value might reflect the process of aging, and frailty in older adults has been raised as another clinically significant feature of this enzyme, to be followed with additional epidemiologic investigation. Timely updated, comprehensive, and systematic introduction of ALT activity is necessary to aid clinicians make better use of this enzyme.

Is there any link between dietary pattern and development of nonalcoholic fatty liver disease in adolescence? An expert review

The prevalence of overweight and obesity in childhood is a major public health concern. According to the obesity trend, the prevalence of pediatric nonalcoholic fatty liver disease (NAFLD) is also increasing. Nonalcoholic fatty liver disease is characterized by a spectrum of hepatic lesions (i.e., steatosis, ballooning, necroinflammation and fibrosis) that can progress to cirrhosis, hepatocellular carcinoma and liver failure with the consequent need for liver transplantation. Pediatric NAFLD is typically of primary origin and it is strongly associated with several features of the metabolic syndrome such as obesity, insulin resistance, dyslipidemia and Type 2 diabetes. The evaluated article reports the prospective relationship between dietary patterns at age 14 years and the presence of NAFLD at age 17 years. A total of 995 adolescents completed a food frequency questionnaire at 14 years and had liver ultrasound at 17 years. Prospective associations between the dietary pattern scores and the risk of NAFLD were analyzed using multiple logistic regression analyses. Nonalcoholic fatty liver disease was present in 15.2% of adolescents. A healthy dietary pattern at 14 years appeared protective against NAFLD at 17 years in centrally obese adolescents. On the contrary, a western dietary pattern at 14 years in this cohort was associated with an increased risk of NAFLD at 17 years, particularly in obese adolescents.

Healthy range of serum alanine aminotransferase and its predictive power for cardiovascular risk in children and adolescents

BACKGROUND AND AIM

Serum alanine aminotransferase (ALT) is not only a surrogate marker of chronic liver disease but also predictive of future development of cardiovascular disease (CVD) in adults; however, pediatric reference data are rare, and "healthy-range ALT limits" have not been assessed to predict cardiovascular risk in children and adolescents.

METHODS

Data from 2242 examinees (1171 boys and 1071 girls; 10-18 years of age) in the Korea National Health and Nutrition Examination Survey IV (2007-2009) were analyzed. The reference values of ALT levels were determined according to age and sex. Multiple logistic regressions were used to assess the association between healthy-range ALT limits (ALT level >30 IU/L for boys and >19 IU/L for girls) and each cardiovascular risk factor.

RESULTS

The 50th, 90th, and 95th percentiles of ALT levels were respectively 14, 27, and 35 IU/L in boys and 11, 19, and 24 IU/L in girls. Subjects with ALT levels higher than healthy-range ALT limits not only exhibited higher odds ratios for metabolic syndrome but also showed higher each cardiovascular risk related to obesity, hypertension, and dyslipidemia compared with subjects whose ALT levels were within the healthy range (P < 0.001).

CONCLUSIONS

The present study shows normal ALT reference data of Korean children and adolescents. The present study also showed the effectiveness of healthy-range ALT limits in predicting each cardiovascular risk factor in a national representative population.