Comparison of the severity of metabolic, liver and cardiovascular damage in NAFLD patients attending the hepatology clinic over the last three decades.

BACKGROUND AND AIMS: NAFLD prevalence is increasing worldwide. AIM: to assess whether severity of hepatic, metabolic and cardiovascular (CV) disease changed over time. METHODS: 422 NAFLD patients (388 biopsy proven and 34 clinical cirrhosis) diagnosed between 1990 and 2021 and subdivided according to decade of presentation. Metabolic parameters, early atherosclerosis (carotid plaques at Doppler ultrasound), severity of liver damage (NAS score, NASH, significant fibrosis (≥2) and cirrhosis) and PNPLA3 genotyping were assessed. RESULTS: No difference in age, sex and prevalence of dyslipidemia and hypertension was found across decades (p for trend), whereas a higher prevalence of diabetes (p = 0.02), obesity (p<0.001), histological severe steatosis (p<0.001), NASH (p<0.001), fibrosis ≥2 (p<0.001), cirrhosis (p<0.001) and carotid plaques (p = 0.05) was observed in the last decade compared to the others. A higher prevalence of PNPLA3 GG polymorphism was found over time (p = 0.02). In the whole cohort, age, metabolic alterations and PNPLA3 G homozygosity were independent risk factors for hepatic fibrosis and carotid plaques, independently of the decade considered. CONCLUSION: Over the past 10 years compared to previous decades, NAFLD patients presented to observation with more severe liver disease and subclinical atherosclerosis, paralleling the spread of diabetes and obesity. PNPLA3 unfavorable genotype became more prevalent over time.

Interaction between Lifestyle Changes and PNPLA3 Genotype in NAFLD Patients during the COVID-19 Lockdown.

The coronavirus disease 2019 (COVID-19) lockdown dramatically changed people's lifestyles. Diet, physical activity, and the PNPLA3 gene are known risk factors for non-alcoholic fatty liver disease (NAFLD). Aim: To evaluate changes in metabolic and hepatic disease in NAFLD patients after the COVID-19 lockdown. Three hundred and fifty seven NAFLD patients were enrolled, all previously instructed to follow a Mediterranean diet (MD). Anthropometric, metabolic, and laboratory data were collected before the COVID-19 lockdown in Italy and 6 months apart, along with ultrasound (US) steatosis grading and information about adherence to MD and physical activity (PA). In 188 patients, PNPLA3 genotyping was performed. After the lockdown, 48% of patients gained weight, while 16% had a worsened steatosis grade. Weight gain was associated with poor adherence to MD (p = 0.005), reduced PA (p = 0.03), and increased prevalence of PNPLA3 GG (p = 0.04). At multivariate analysis (corrected for age, sex, MD, PA, and PNPLA3 GG), only PNPLA3 remained independently associated with weight gain (p = 0.04), which was also associated with worsened glycemia (p = 0.002) and transaminases (p = 0.02). During lockdown, due to a dramatic change in lifestyles, half of our cohort of NAFLD patients gained weight, with a worsening of metabolic and hepatologic features. Interestingly, the PNPLA3 GG genotype nullified the effect of lifestyle and emerged as an independent risk factor for weight gain, opening new perspectives in NAFLD patient care.

Lipophagy Impairment Is Associated With Disease Progression in NAFLD.

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in Western countries and is associated with aging and features of metabolic syndrome. Lipotoxicity and oxidative stress are consequent to dysregulation of lipid metabolism and lipid accumulation, leading to hepatocyte injury and inflammation. Lipophagy consists in selective degradation of intracellular lipid droplets by lysosome and mounting evidence suggests that lipophagy is dysregulated in NAFLD. Here we demonstrate lipophagy impairment in experimental models of NAFLD and in a NAFLD patient cohort by histomorphological and molecular analysis. High fat diet-fed C57BL/6J male mice and high-fat/high-glucose cultured Huh7 cells showed accumulation of both p62/SQSTM1 and LC3-II protein. In 59 NAFLD patients, lipid droplet-loaded lysosomes/lipolysosomes and p62/SQSTM1 clusters correlated with NAFLD activity score (NAS) and with NAS and fibrosis stage, respectively, and levels of expression of lysosomal genes, as well as autophagy-related genes, correlated with NAS and fibrosis stage. An increased amount of lipid droplets, lipolysosomes and autophagosomes was found in subjects with NAFLD compared to healthy subjects at ultrastructural level. In conclusion, here we observed that NAFLD is characterized by histological, ultrastructural and molecular features of altered autophagy that is associated with an impaired lipid degradation. Impaired autophagy is associated with features of advanced disease. Lipopolysosomes, as individuated with light microscopy, should be further assessed as markers of disease severity in NAFLD patients.

An overview of deregulated lipid metabolism in nonalcoholic fatty liver disease with special focus on lysosomal acid lipase.

Obesity and type 2 diabetes are frequently complicated by excess fat accumulation in the liver, which is known as nonalcoholic fatty liver disease (NAFLD). In this context, liver steatosis develops as a result of the deregulation of pathways controlling de novo lipogenesis and fat catabolism. Recent evidences suggest the clinical relevance of a reduction in the activity of lysosomal acid lipase (LAL), which is a key enzyme for intracellular fat disposal, in patients with NAFLD. In this review, we provided a comprehensive overview of the critical steps in hepatic fat metabolism and alterations in these pathways in NAFLD, with a special focus on lipophagy and LAL activity. During NAFLD, hepatic fat metabolism is impaired at several levels, which is significantly contributed to by impaired lipophagy, in which reduced LAL activity may play an important role. For further research and intervention in NAFLD, targeting LAL activity may provide interesting perspectives.