Estimation of Upper Limit of Normal for Serum Alanine Transaminase in Healthy South Indian Population

Role of serum endotoxin, FGF19, TLR2, TNF-α, IL-12 and IL-10 in NAFLD-associated T2DM pathogenesis: Insights into Th1 bias and protective mechanisms

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) in non-obese patients is pathophysiologically distinct, exhibiting common immunological link with type-2 diabetes mellitus (T2DM). This study aims to delineate the role of Toll-like receptor 2 (TLR2)-mediated immuno-modulation along with its association with fibroblast growth factor receptor 4 (FGFR4) and its ligand fibroblast growth factor 19 (FGF19) in the pathogenesis of NAFLD without or with T2DM.

METHODOLOGY

Blood samples were collected from patients with NAFLD (n = 90), NAFLD with T2DM (n = 90) and healthy cohorts (n = 90) with consent and clinical records. Real-time polymerase chain reaction (PCR), enzyme-linked immunoassay (ELIZA) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) were used to analyze messenger ribonucleic acid (mRNA), protein expression and gene polymorphism.

RESULTS

The molecular genetic analysis revealed the prevalence of variant allele(A) in FGFR4 gene in both cases compared to controls. The mRNA expression of FGF19 and TLR2 exhibited significant upregulation in NAFLD without T2DM compared to NAFLD with T2DM. Tumor necrosis factor-α (TNF-α) and interleukin-12 (IL-12) showed upregulation in both disease cohorts compared to control while IL-10 showed significant downregulation in NAFLD with T2DM compared to the other two cohorts. Correlation analysis between FGF19 and TLR2 revealed significant positive association in both NAFLD with and without T2DM. The Th1:Th2 ratio showed significant upregulation in NAFLD with T2DM compared to NAFLD without T2DM.

CONCLUSION

In conclusion, elevated serum endotoxin levels appear to contribute to NAFLD and T2DM development. Upregulated FGF19 seems to be protective against developing T2DM in NAFLD patients. Higher TLR2, TNF-α and IL-12 expression in NAFLD without T2DM suggests a Th1 bias in its pathogenesis, while reduced IL-10 in NAFLD with T2DM implies a more skewed Th1 state in this condition.

Association of De Ritis Ratio with Prognosis in Patients with Coronary Artery Disease and Aminotransferase Activity within and outside the Healthy Values of Reference Range

BACKGROUND

The aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio (De Ritis ratio), obtained from AST and ALT activities in the healthy range, has not been studied in association with mortality.

METHODS

This study included 3392 patients with stable coronary heart disease and aminotransferase activity in the reference range. Patients are categorized into two groups: a group with AST and ALT activity in the healthy range (n = 1697), and a group with AST and/or ALT activity outside the healthy range but in the reference range (n = 1695). The primary endpoint was all-cause mortality at three years.

RESULTS

The De Ritis ratio (median 5th-95th percentile] was 0.94 [0.61-1.41] in patients with AST and ALT in the healthy range and 0.93 [0.45-1.96] in patients with AST and/or ALT outside the healthy range (p = 0.700). At three years, there were 86 deaths in patients with AST and ALT in the healthy range: 27 deaths (3.9%) in patients with a De Ritis ratio ≤median, and 59 deaths (8.2%) in patients with the De Ritis ratio >median (adjusted hazard ratio [HR] = 1.16, 95% confidence interval [CI] 0.94 to 1.42; p = 0.159); in patients with AST and/or ALT outside the healthy range, there were 148 deaths: 49 deaths (6.6%) in patients with a De Ritis ratio ≤median, and 99 deaths (14.1%) in patients with De Ritis ratio >median (adjusted HR = 1.27 [1.09-1.48], p = 0.002), with both HRs calculated per unit higher values of the De Ritis ratio.

CONCLUSIONS

The De Ritis ratio obtained from AST and ALT activity in the healthy range was not independently associated with higher risk of mortality. The De Ritis ratio obtained from aminotransferase activity outside the healthy range (but still in the reference range) was independently associated with the risk of mortality.

Prevalence of elevated alanine aminotransferase levels in adult participants from a community-based study from northern part of India

Alanine aminotransferase (ALT) is a cytosolic enzyme specific to hepatocytes, and its elevated level in the peripheral blood denotes liver cell injury. Detection of persistently elevated ALT levels during routine health check-up in asymptomatic or symptomatic individuals provides a window of opportunity to explore the causes of liver cell damage and for the timely institution of appropriate treatment. This was a retrospective study using a subset of the data from a previous community-based prospective study done for the estimation of the prevalence of celiac disease (CD) in India,  during which estimation of ALT levels in the blood samples of participants was also carried out. Of the 11,053 individuals (4399 [39.8%] males; mean age 37.9 ± 13.3 years) screened, 6209 consented to provide blood samples for testing for CD. Of these, assessment of serum ALT levels was done in 6083 (2235 [36.7%] males) patients. ALT was elevated above the upper limit of normal (ULN) (> 40 IU/L) in 1246 (20.5%) of the participants and > 1.5 times (> 60 IU/L) in 329 (5.4%) participants. The ALT levels were elevated more frequently in men as compared to women (29.4% vs. 15.3%, p < 0.001). There was a significant positive correlation (Pearson correlation coefficient [r] = 0.25, p < 0.0001) between ALT levels and body mass index (BMI). With increasing age, there was a significant decrease in the proportion of subjects with ALT ≥ 1.5× ULN (p < 0.001). Our results suggest that a high proportion (20.5%) of individuals otherwise considered healthy have values of ALT level in the serum above the "normal" range/cut-off suggesting likely ongoing underlying liver damage. There is a need for measures to evaluate and, if found, treat the underlying cause for the same.

Prevalence and predictors of nonalcoholic fatty liver disease in South Asian women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary disease (PCOS) may be a risk factor for nonalcoholic fatty liver disease (NAFLD) due to common pathogenetic pathways, including insulin resistance and obesity. Both PCOS and NAFLD are more severe in South Asian women. Data on NAFLD in South Asian women with PCOS are lacking.

AIM

To investigate prevalence and predictors of NAFLD and liver fibrosis in PCOS patients from South Asia.

METHODS

We conducted an observational routine screening program by means of transient elastography (TE) with associated controlled attenuation parameter (CAP). NAFLD was defined as CAP ≥ 288 decibels per meter. Significant liver fibrosis (stage 2 and higher out of 4) was defined as TE measurement ≥ 8.0 kilopascals. Elevated alanine aminotransferase (ALT) was defined as ALT > 24 IU/L, as per upper limit of normal reported in South Asian women. Biochemical hyperandrogenism was defined as free androgen index > 5. Predictors of NAFLD were determined by logistic regression analysis.

RESULTS

101 PCOS patients (mean age 36.3 years) with no significant alcohol intake or viral hepatitis were included. Prevalence of NAFLD and significant liver fibrosis was 39.6% and 6.9%, respectively. Elevated ALT was observed in 40% and 11.5% of patients with and without NAFLD, respectively. After adjusting for duration of PCOS and insulin resistance measured by homeostasis model for assessment of insulin resistance, independent predictors of NAFLD were higher body mass index [adjusted odds ratio (aOR) 1.30, 95% confidence interval (CI): 1.13-1.52], hyperandrogenism (aOR: 5.32, 95%CI: 1.56-18.17) and elevated ALT (aOR: 3.54, 95%CI: 1.10-11.47). Lifetime cardiovascular risk was higher in patients with NAFLD compared to those without NAFLD (0.31 ± 0.11 vs 0.26 ± 0.13).

CONCLUSION

Despite their young age, NAFLD diagnosed by TE with CAP is a frequent comorbidity in South Asian women with PCOS and is strongly associated with higher body mass index and hyperandrogenism. Non-invasive screening strategies could help early diagnosis and initiation of interventions, including counselling on weight loss, cardiovascular risk stratification and linkage to hepatology care where appropriate.