Mitochondrial DNA does not contribute to the heritability of non-alcoholic fatty liver disease

Systematic review of genetic association studies involving histologically confirmed non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease has an increasing prevalence in Western countries, affecting up to 20% of the population.

Regional anthropometric measures associated with the severity of liver injury in patients with non-alcoholic fatty liver disease

BACKGROUND

Not all NAFLD patients are obese and many obese patients do not have NAFLD. Impaired peripheral fat storage may increase the delivery of lipids to the liver and facilitate NAFLD progression.

AIM

To assess the association of anthropometric measures of regional adiposity including arm fat index (AFI) (upper body fat), waist circumference (visceral fat) and body mass index (total body fat) on liver injury and fibrosis in NAFLD.

METHODS

One hundred and forty-one patients with histological evidence of NAFLD were included in this study. Multivariate logistic regression models examined the contribution of age, sex, body mass index, AFI, triceps fold thickness (TST), waist and hip circumference to the odds of liver injury (NAS scores ≥3) and fibrosis (fibrosis scores ≥2) by liver biopsy.

RESULTS

Arm fat index (OR: 0.82, 95% CI: 0.59-0.91) and TST (OR: 0.13, 95% CI: 0.04-0.42) were negatively correlated with NAFLD histological severity. In women, waist circumference was positively correlated with NAFLD severity (OR: 1.21(1.02-1.44). Age (OR: 1.05, 95% CI: 1.01-1.0) and waist circumference (OR: 1.07, 95% CI: 1.00-1.15) were significantly associated with fibrosis risk. In women, AFI (OR: 0.87, 95% CI: 0.76-0.99) and TST (OR: 0.22, 95% CI: 0.05-0.95) were negatively associated with fibrosis risk.

CONCLUSIONS

Regional anthropometric measures are associated with severity of NAFLD in a sex-specific manner. Men and women with lower arm fat depots and women with bigger waist circumference have a greater likelihood of liver injury. Age and waist circumference seem to be associated with liver fibrosis. Simple anthropometric measurements of peripheral fat deposits may help stratify significant liver injury risk.

Role of mitochondria in nonalcoholic fatty liver disease--from origin to propagation

OBJECTIVES

Mitochondria play a major role in cell energy-generating processes and integrate several signalling pathways to control cellular life and death.

DESIGN AND METHODS

Several liver diseases are characterized by mitochondrial alterations which are directly or indirectly dependent on the activation of intracellular stress cascades or receptor-mediated pathways. This article examines the role of mitochondrial dysfunction in critical initiating or propagating events in fatty liver infiltration and nonalcoholic fatty liver disease (NAFLD). Genetic variants and the role of drug-induced toxicity have been considered.

RESULTS

Key alterations of mitochondrial physiology associated with hepatocyte fatty changes are described. The value of novel non-invasive diagnostic methods to detect mitochondrial metabolic alterations is also discussed.

CONCLUSIONS

Mitochondrial metabolic remodeling is a predominant factor in the appearance and perpetuation of hepatocyte fat accumulation. Non-invasive techniques to identify mitochondrial dysfunction and proper mitochondria protection are two necessary clinical steps for an efficient management of NAFLD.