Transaminase Concentrations Cannot Separate Non-Alcoholic Fatty Liver and Non-Alcoholic Steatohepatitis in Morbidly Obese Patients Irrespective of Histological Algorithm

BACKGROUND

In current general practice, elevated serum concentrations of liver enzymes are still regarded as an indicator of non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH). In this study, we analyzed if an adjustment of the upper limit of normal (ULN) for serum liver enzymes can improve their diagnostic accuracy.

METHODS

Data from 363 morbidly obese patients (42.5 ± 10.3 years old; mean BMI: 52 ± 8.5 kg/m2), who underwent bariatric surgery, was retrospectively analyzed. NAFL and NASH were defined histologically according to non-alcoholic fatty liver activity score (NAS) and according to steatosis activity fibrosis (SAF) score for 2 separate analyses, respectively.

RESULTS

In 121 women (45%) and 45 men (46%), elevated values for at least one serum parameter (ALT, AST, γGT) were present. The serum concentrations of ALT (p < 0.0001), AST (p < 0.0001) and γGT (p = 0.0023) differed significantly between NAFL and NASH, irrespective of the applied histological classification method. Concentrations of all 3 serum parameters correlated significantly positively with the NAS and the SAF score, with correlation coefficients between 0.33 (ALT/NAS) and 0.40 (γGT/SAF). The area under the curves to separate NAFL and NASH by liver enzymes achieved a maximum of 0.70 (ALT applied to NAS-based classification). For 95% specificity, the ULN for ALT would be 47.5 U/L; for 95% sensitivity, the ULN for ALT would be 17.5 U/L, resulting in 62% uncategorized patients.

CONCLUSION

ALT, AST, and γGT are unsuitable for non-invasive screening or diagnosis of NAFL or NASH. Utilizing liver enzymes as an indicator for NAFLD or NASH should generally be questioned.

Effects of football sporting activity on renal and liver functions among young undergraduate students of a Nigerian tertiary institution

Background

Football sporting exercise is one of the most popular events in the world. While there are well-documented reports on the effects of different athletic sporting activities on the biochemical markers of renal and liver functions, there are paucity of well-documented reports on the effects of football activity on Nigerian sportsmen, hence the need for this study.

Method

Biochemical markers of renal and liver functions (urea, creatinine, aspartate aminotransaminase (AST), alanine aminotransaminase (ALT), alkaline phosphatase (ALP)) were determined using Cobas c 111 auto-analyser by Roche.

Results

The mean urea (mmol/L)±SEM, creatinine (μmol/L)±SEM, AST (U/L)±SEM, ALT (U/L)±SEM and ALP (U/L)±SEM values before and after soccer exercise were 3.56±0.12, 3.76±0.13, p=0.000; 79.36±1.53, 95.90±2.03, p=0.000; 32.54±1.15, 35.81±1.32, p=0.000; 15.68±1.02, 13.97±0.81, p=0.000; and 82.21±3.67, 86.08±3.86, p=0.046, respectively. Pearson’s degree of association for AST and ALT before and after exercise were r=0.678, p=0.000 and r=0.770, p=0.000, respectively; ALT and ALP before exercise showed a positive and significant association (r=0.317, p=0.028). On the other hand, there was a negative but insignificant correlation between urea before exercise and ALP after exercise (r=−0.003, p=0.982) and urea before exercise versus AST after exercise (r=−0.120, p=0.418). A positive but insignificant association was observed between urea and creatinine before exercise (r=0.093, p=0.530).

Conclusion

Football sporting event is associated with an increase in urea, creatinine, AST and ALP plasma values, and such interpretation of these parameters among sportsmen should be done with caution.

Cardiorespiratory fitness, waist circumference and liver enzyme levels in European adolescents: The HELENA cross-sectional study

OBJECTIVES

(1) To examine whether cardiorespiratory fitness (CRF) is related to liver enzyme levels independent of waist circumference (WC), and (2) To test whether having a high CRF is associated with an improved liver enzyme profile with a high WC.

DESIGN

Cross-sectional.

METHODS

CRF (20m-shuttle-run test) and WC were assessed in 811 European adolescents (48.5% males) aged 12.5-17.5 years. Fatty liver biomarkers included fasting serum alanine-aminotransferase (ALT), gamma-glutamyl-transpeptidase (GGT) and the aspartate-aminotransferase to ALT (AST/ALT) ratio. Participants were categorized as fit or unfit (CRF below or above 43.8mL/kg/min and 34.6mL/kg/min, for boys and girls, respectively) and as high or non-high WC (sex and age-specific cut-offs).

RESULTS

CRF was associated with ALT (β=-0.106; p=0.049) and GGT levels (β=-0.225; p<0.001) and AST/ALT ratio (β=0.234; p<0.001), yet these relationships were attenuated after further controlling for WC (all p>0.1). High WC and fit adolescents had lower ALT levels (28±1U/L vs. 23±2U/L, unfit and fit respectively, p=0.018) and higher AST/ALT ratio (0.94±0.04 vs. 1.10±0.06, unfit and fit respectively, p=0.010) than those who were high WC but unfit.

CONCLUSIONS

The results showed that CRF is not independently associated with liver enzymes, and that WC is a stronger predictor in adolescents. These findings also suggest that high CRF may have specific protective effects on liver enzyme levels in adolescents with high WC. Exercise programs focused on increasing CRF and decreasing abdominal adiposity could be a good alternative in the treatment and prevention of obesity related fatty liver disease in adolescents.

Liver enzymes, metabolomics and genome-wide association studies: From systems biology to the personalized medicine

For several decades, serum levels of alanine (ALT) and aspartate (AST) aminotransferases have been regarded as markers of liver injury, including a wide range of etiologies from viral hepatitis to fatty liver. The increasing worldwide prevalence of metabolic syndrome and cardiovascular disease revealed that transaminases are strong predictors of type 2 diabetes, coronary heart disease, atherothrombotic risk profile, and overall risk of metabolic disease. Therefore, it is plausible to suggest that aminotransferases are surrogate biomarkers of “liver metabolic functioning” beyond the classical concept of liver cellular damage, as their enzymatic activity might actually reflect key aspects of the physiology and pathophysiology of the liver function. In this study, we summarize the background information and recent findings on the biological role of ALT and AST, and review the knowledge gained from the application of genome-wide approaches and “omics” technologies that uncovered new concepts on the role of aminotransferases in human diseases and systemic regulation of metabolic functions. Prediction of biomolecular interactions between the candidate genes recently discovered to be associated with plasma concentrations of liver enzymes showed interesting interconnectivity nodes, which suggest that regulation of aminotransferase activity is a complex and highly regulated trait. Finally, links between aminotransferase genes and metabolites are explored to understand the genetic contributions to the metabolic diversity.

ALG1-CDG: a new case with early fatal outcome

Congenital disorders of glycosylation (CDG) are a growing group of inherited metabolic disorders where enzymatic defects in the formation or processing of glycolipids and/or glycoproteins lead to variety of different diseases. The deficiency of GDP-Man:GlcNAc2-PP-dolichol mannosyltransferase, encoded by the human ortholog of ALG1 from yeast, is known as ALG1-CDG (CDG-Ik). The phenotypical, molecular and biochemical analysis of a severely affected ALG1-CDG patient is the focus of this paper. The patient's main symptoms were feeding problems and diarrhea, profound hypoproteinemia with massive ascites, muscular hypertonia, seizures refractory to treatment, recurrent episodes of apnoea, cardiac and hepatic involvement and coagulation anomalies. Compound heterozygosity for the mutations c.1145T>C (M382T) and c.1312C>T (R438W) was detected in the patient's ALG1-coding sequence. In contrast to a previously reported speculation on R438W we confirmed both mutations as disease-causing in ALG1-CDG.