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

Continuous age- and sex-specific reference ranges of liver enzymes in Chinese children and application in pediatric non-alcoholic fatty liver disease

BACKGROUND

Alanine aminotransferase (ALT) is widely used to screen patients with hepatic diseases. However, the current reference ranges (< 50 U/L) were developed by laboratories and have not been validated in populations with a large number of healthy individuals.

METHODS

This study collected venous blood and anthropometric data from a total of 13,287 healthy children aged 3 months to 18 years who underwent routine physical examinations in the Department of Pediatric Healthcare. We applied the least mean square algorithm to establish age- and sex-related reference percentiles of serum levels of transaminases. For validation, we recruited 4276 children and adolescents with obesity/overweight who underwent evaluation and metabolic tests in the hospital. Using receiver operating characteristic curves, we determined age- and sex-specific upper limit percentiles of liver enzymes for fatty liver diseases.

RESULTS

This study revealed a significant correlation between serum transaminase levels and age and sex (P < 0.01). These transaminase levels exhibited age- and sex-specific patterns. Among individuals in the non-alcoholic fatty liver disease (NAFLD) cohort, elevated ALT levels displayed a positive association with clinical markers of disease severity, including homeostatic model assessment of insulin resistance, waist-hip ratio, and serum uric acid levels (P < 0.01). According to the receiver operating characteristic curves, ALT levels at the 92.58th percentile for boys and the 92.07th percentile for girls yielded the highest accuracy and specificity.

CONCLUSIONS

This study provides age- and sex-specific reference ranges for ALT, aspartate aminotransferase, and γ-glutamyltransferase in Chinese children and adolescents, making it the largest population study to date. Furthermore, the study establishes a precise upper limit for ALT levels, facilitating their use in NAFLD screening. Video Abstract.

Prevalence of Elevated ALT in Adolescents in the US 2011-2018

OBJECTIVE

The objective of this study is to characterize suspected nonalcoholic fatty liver disease (NAFLD) using elevated alanine aminotransferase (ALT) in a diverse and nationally representative cohort of adolescents and to characterize higher ALT elevation in adolescents with obesity.

METHODS

Data from the National Health and Nutrition Examination Survey 2011-2018 were analyzed for adolescents 12-19 years. Participants with causes for elevated ALT other than NAFLD were excluded. Race and ethnicity, sex, body mass index (BMI), and ALT were examined. Elevated ALT was defined as >22 U/L (females) and >26 U/L (males) using the biologic upper normal limit (ULN). Elevated ALT thresholds up to 2X-ULN were examined among adolescents with obesity. Multivariable logistic regression was used to determine the association of race/ethnicity and elevated ALT, adjusting for age, sex, and BMI.

RESULTS

Prevalence of elevated ALT in adolescents was 16.5% overall and 39.5% among those with obesity. For White, Hispanic, and Asian adolescents, prevalence was 15.8%, 21.8%, and 16.5% overall, 12.8%, 17.7%, and 27.0% in those with overweight, and 43.0%, 43.5%, and 43.1% in those with obesity, respectively. Prevalence was much lower in Black adolescents (10.7% overall, 8.4% for overweight, 20.7% for obesity). Prevalence of ALT at 2X-ULN was 6.6% in adolescents with obesity. Hispanic ethnicity, age, male sex, and higher BMI were independent predictors of elevated ALT.

CONCLUSIONS

Prevalence of elevated ALT in U.S. adolescents is high, affecting 1 in 6 adolescents during 2011-2018. The risk is highest in Hispanic adolescents. Asian adolescents with elevated BMI may comprise an emerging risk group for elevated ALT.

Low intensity pulsed ultrasound reduces liver inflammation caused by fatigue exercise

Low-intensity pulsed ultrasound (LIPUS) has been shown to have many benefits, such as inhibiting inflammation, stimulating cell proliferation and differentiation, promoting angiogenesis, and so on. So, can exercise fatigue induced liver inflammation be effectively relieved by LIPUS? If possible, what is the possible mechanism? This study first investigated the effect of different intensity exercise on liver inflammation. Rats were divided into three groups: normal control group, exercise fatigue group, and aerobic exercise group. The results showed that aerobic exercise increases both anti-inflammatory factors and pro-inflammatory factors, while fatigue exercise decreases anti-inflammatory factors and increases pro-inflammatory factors, leading to severe liver injury and fibrosis. Then, we investigated the therapeutic effect of LIPUS on liver inflammation caused by exercise fatigue. Starting from the 6th week, the liver was irradiated with LIPUS of 80 mW/cm² for 20 min/d after daily exercise for 7 weeks. The results showed that LIPUS significantly decreased liver injury and fibrosis, significantly up-regulated the expression of STAT6, IL-13, and its receptors IL-13Rα1, and down regulated the expression of NF-κBp65 in exercise fatigue rats. These results indicate that LIPUS can reduce fatigue-induced liver inflammation, and the mechanism is related to the regulation of the IL-13/STAT6/NF-κBp65 pathway.

The burden and sexual dimorphism with nonalcoholic fatty liver disease in Asian children: A systematic review and meta-analysis

BACKGROUND

Despite substantial attention paid to the epidemic of nonalcoholic fatty liver disease (NAFLD) in adults, data on the burden and sexual dimorphism of NAFLD in Asian children have not yet been synthesized.

METHODS

We conducted a literature search of 735 references up to April 2021. Pooled analyses, stratified analyses and meta-regression were all performed.

RESULTS

Thirty-three study populations were finally included. Nine of them comprising 20 595 children showed an overall NAFLD prevalence of 5.53% (95% CI 3.46%-8.72%), in which, 36.64% (95% CI, 27.99%-46.26%) NAFLD subjects had elevated levels of ALT. The prevalence rate of NAFLD increased about 1.6-fold from 2004 to 2010 to the last decade. Male predominant trends were observed in paediatric NAFLD (boys: 8.18%, 95% CI 4.93%-13.26%; girls: 3.60%, 95% CI 1.60%-7.87%). Moreover, meta-analysis showed that after 10 years of age, boys were more prone to have NAFLD than girls (OR = 1.75; P = .0012). In addition, the pooled prevalence of NAFLD increased sequentially in normal-weight (1.49%, 95% CI 0.88%-2.51%, n = 2610), overweight (16.72%, 95% CI 7.07%-34.65%, n = 1265) and obese children (50.13%, 95% CI 41.99%-58.27%, n = 6434 individuals). After full covariate adjustment, the multivariate meta-regression also showed that boy percentage (P = .0396) and body mass index (P < .0001) were positively correlated with prevalent NAFLD.

CONCLUSIONS

In Asia, paediatric NAFLD is becoming prevalent over the recent decades, particularly among obese children and boys after 10 years old. The hormonal and chromosomal origins of paediatric NAFLD dimorphism need further investigation.

Updated upper limit of normal for serum alanine aminotransferase value in Vietnamese population

BACKGROUND

Alanine aminotransferase (ALT) is a marker of hepatic damage and its range can be affected by viral hepatitis, alcoholic hepatitis and non-alcoholic fatty liver diseases. We aimed to study the factors associated with higher ALT level and update the upper limit of normal (ULN) in the Vietnamese population.

METHODS

This cross-sectional study enrolled 8383 adults, aged 18 years and older who visited the Medical Center at Ho Chi Minh City for a health check-up. Following the exclusion criteria, 6677 subjects were included in the analysis.

RESULTS

Age ≤40 years, male gender, body mass index >23 kg/m2, diastolic blood pressure >85 mm Hg, cholesterol >5.2 mmol/L, triglyceride >1.7 mmol/L, positivity, anti-hepatitis C virus positivity and fatty liver (p<0.05) were associated with higher ALT level (>40 U/L). Without considering age and gender, healthy group is defined after exclusion of participants with one of the mentioned contributing factors. The median ALT level in the healthy group was 18 in men and 13 in women. The ULN at the 95th percentile of the healthy group was 40 U/L in men and 28 U/L in women.

CONCLUSION

The ULN for ALT in healthy women was lower than in healthy men. Updated ULN for ALT level can promote the identification of unhealthy subjects. More studies that involve ethnicity and lifestyle factors are needed to confirm the new ULN in the Vietnamese population.

Exercise Affects the Formation and Recovery of Alcoholic Liver Disease through the IL-6-p47phox Oxidative-Stress Axis

(1) Background: To explore the effect of exercise on the formation and recovery of alcoholic liver disease (ALD) and whether the IL-6−p47phox oxidative−stress axis is involved in that process. (2) Methods: Firstly, 23 six-week-old male C57BL/6J mice were randomly divided into the Con group, ALD group, ALD + NOXI group, ALD + Ex group, and ALD + Ex + NOXI group. The Liber−DeCarli alcoholic liquid diet was used for 6 weeks to establish the ALD mice model, and the Con group was given the TP4030C control diet. The remaining groups were fed with the TP4030B alcoholic diet, and exercise intervention was started after the ALD model establishment and lasted for another 6 weeks, with or without administration of the NOX inhibitor apocynin by intraperitoneal injection on every exercise training day. Secondly, 28 mice were randomly divided into the Sed group, Eth group, Eth + Ex group and Eth + Ex + NOXI group. The Sed group was given the TP4030C control diet. The remaining groups were fed with the TP4030B alcoholic diet and exercise intervention was started synchronously combined with or without administration of intraperitoneal apocynin injections on every exercise training day for 5 weeks. After each individual experiment was accomplished, physiological assessment and biochemical analysis of blood and tissue samples were examined. (3) Results: The levels of TG in serum and IL-6 protein content in liver tissue in the ALD group were significantly increased compared to the Con group (p < 0.05); compared with ALD, p47phox expression in muscle was increased significantly in the ALD + NOXI group (p < 0.05), and TG in serum decreased in the ALD + Ex group (p < 0.05). TG in serum, AST/ALT ratio, and IL-6 content in both liver and muscle decreased (p < 0.05) in the ALD + Ex + NOXI group with MDA in muscle significantly increased (p < 0.01). The AST/ALT ratio, TG in serum, SOD in liver, and p47phox in both liver and muscle in the ALD + Ex + NOXI group were significantly decreased compared with the ALD + NOXI group (p < 0.01). Compared with the ALD + Ex group, the liver index and HDL-C levels in serum were decreased (p < 0.05) in the ALD + Ex + NOXI group. The degree of hepatocyte steatosis and inflammatory infiltration were ameliorated after exercise intervention. In the Eth group, the relative epididymal fat content, HDL-C level, and AST/ALT ratio were significantly decreased, and TG and gp91phox in liver were significantly higher than in the Sed group (p < 0.05, p < 0.01). Compared with the Eth group, the AST/ALT ratio, MDA in the liver, and NOX4 and p47phox protein expression in the liver were significantly increased, and body weight decreased significantly in the Eth + Ex group (p < 0.05, p < 0.01), as did TG in the liver and MDA in muscle. In the th + Ex + NOXI group, gp91phox expression in the liver and body weight were significantly decreased (p < 0.05, p < 0.01). In the Eth + Ex + NOXI group, the ratio of AST/ALT and MDA in muscle were increased when compared with the Eth + Ex group, and the protein expression of gp91phox and p47phox were much lower (p < 0.01). (4) Conclusions: 6 weeks of exercise intervention during the recovery phase of ALD ameliorates hepatocyte damage and dyslipidemia through the IL-6−p47phox oxidative−stress axis, and applying a NOX inhibitor in combination could optimize this. However, drinking alcohol during exercise exacerbates dyslipidemia and oxidative stress, with hepatocyte IL-6−p47phox downregulated.

Transient Elastography in the Diagnosis of Pediatric Non-alcoholic Fatty Liver Disease and Its Subtypes

OBJECTIVE

To study the diagnosis efficacy of controlled attenuation parameters (CAP) and liver stiffness measurement (LSM) in the transient elastography of non-alcoholic fatty liver disease (NAFLD) and its subtypes in children with obesity.

METHODS

Retrospectively analyze children with obesity in the Childhood Obesity Clinic of the Affiliated Hospital of Hangzhou Normal University from July 2020 to March 2021. The correlation between clinical data and NAFLD subtypes was analyzed, and included the relevant clinical data into the receiver operating characteristic curve for diagnosis and prediction.

RESULTS

120 children aged between 6.1 and 17.8 years, with 70 males (58.33%), 50 females (41.67%), and a ratio of 1.4:1, were enrolled in the study. CAP and LSM correlated in all subtypes of NAFLD. The correlation was significant for diagnosing NAFLD in children with obesity when CAP > 258.00 dB/m and LSM > 4.65 kPa. It was also significant for NASH diagnosis when CAP > 276.00 dB/m and LSM > 5.15 kPa, while it was less significant for diagnosing NAFLD in children with obesity.

CONCLUSIONS

CAP and LSM have diagnostic efficacy for NAFLD and its subtypes in children with obesity, with optimal predictive values of CAP > 258.00 dB/m and LSM > 4.65 kPa for NAFLD in children with obesity, and CAP > 276.00 dB/m and LSM > 5.15 kPa for NASH in children with obesity.

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.