scholarly journals Vitamin D and Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD): An Update

Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3302 ◽  
Author(s):  
Ilaria Barchetta ◽  
Flavia Agata Cimini ◽  
Maria Gisella Cavallo

Non-alcoholic fatty liver disease (NAFLD) is the first cause of chronic liver disease worldwide; it ranges from simple steatosis to steatohepatitis (NASH) and, potentially, cirrhosis and hepatocarcinoma. NAFLD is also an independent risk factor for type 2 diabetes, cardiovascular diseases, and mortality. As it is largely associated with insulin resistance and related disorders, NAFLD has been recently re-named as Metabolic dysfunction-Associated Fatty Liver Disease (MAFLD). At present, there are no approved pharmacological treatments for this condition. Vitamin D is a molecule with extensive anti-fibrotic, anti-inflammatory, and insulin-sensitizing properties, which have been proven also in hepatic cells and is involved in immune-metabolic pathways within the gut–adipose tissue–liver axis. Epidemiological data support a relationship hypovitaminosis D and the presence of NAFLD and steatohepatitis (NASH); however, results from vitamin D supplementation trials on liver outcomes are controversial. This narrative review provides an overview of the latest evidence on pathophysiological pathways connecting vitamin D to NAFLD, with emphasis on the effects of vitamin D treatment in MAFLD by a nonsystematic literature review of PubMed published clinical trials. This article conforms to the Scale for Assessment of Narrative Review Articles (SANRA) guidelines. Evidence so far available supports the hypothesis of potential benefits of vitamin D supplementation in selected populations of NAFLD patients, as those with shorter disease duration and mild to moderate liver damage.

Author(s):  
Jeniffer Danielle M. Dutra ◽  
Quelson Coelho Lisboa ◽  
Silvia Marinho Ferolla ◽  
Carolina Martinelli M. L. Carvalho ◽  
Camila Costa M. Mendes ◽  
...  

Abstract. Some epidemiological evidence suggests an inverse correlation between non-alcoholic fatty liver disease (NAFLD) frequency and vitamin D levels. Likewise, a beneficial effect of vitamin D on diabetes mellitus (DM) and insulin resistance has been observed, but this is an unsolved issue. Thus, we aimed to investigate the prevalence of hypovitaminosis D in a NAFLD Brazilian population and its association with disease severity and presence of comorbidities. In a cross-sectional study, the clinical, biochemical and histological parameters of 139 NAFLD patients were evaluated according to two different cut-off points of serum 25-hydroxyvitamin D levels (20 ng/mL and 30 ng/mL). The mean age of the population was 56 ± 16 years, most patients were female (83%), 72% had hypertension, 88% dyslipidemia, 46% DM, 98% central obesity, and 82% metabolic syndrome. Serum vitamin D levels were < 30 ng/mL in 78% of the patients, and < 20 ng/mL in 35%. The mean vitamin D level was 24.3 ± 6.8 ng/mL. The comparison between the clinical, biochemical and histological characteristics of the patients according to the levels of vitamin D showed no significant difference. Most patients with NAFLD had hypovitaminosis D, but low vitamin D levels were not related to disease severity and the presence of comorbidities.


2021 ◽  
Vol 75 (4) ◽  
pp. 335-343
Author(s):  
Terezia Kráľová ◽  
Marek Pršo ◽  
Daniel Čierny ◽  
Zuzana Michnová ◽  
Zuzana Havlíčeková ◽  
...  

Background: Insulin resistance (IR) plays a key role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Hypovitaminosis D is associated with several diseases, including hepatic steatosis and obesity. Vitamin D (VD) affects insulin secretion and improves tissue sensitivity to insulin, suggesting that hypovitaminosis D is also associated with IR. The leptin-to-adiponectin ratio (LAR) was investigated as a new marker of IR. Aim: The aim of our study was to determine the association between the VD status, NAFLD and IR in paediatric overweight or obese patients. Methods: The study ran from January 2018 to August 2020 and included 100 subjects. We measured their anthropometric parameters, determined their basic laboratory parameters and the level of leptin and adiponectin, calculated BMI, WHR, WHtR, LAR and HOMA-IR. We measured the degree of hepatic steatosis by obtaining the hepatorenal index (HRI) using ultrasonography, and used real-time elastography to determine the elasticity of the liver parenchyma (LFI). Subsequently, we compared the groups of patients with and without hepatic steatosis and looked for correlations in relation to the level of VD and IR. Results: 4.4% of patients had a severe VD deficiency, 55% of the children had hypovitaminosis D, 28.6% had VD insufficiency and 12% of patients had sufficient VD levels. Patients with significant hepatic steatosis (HRI 1.5 and more) had the lowest level of VD (16.61 ±5.62 μg/l, P = 0.015). The level of VD in patients with hepatic steatosis was inversely correlated with waist circumference, hip circumference, height, weight, triacylglycerols, GMT, C-peptide, insulin, HOMA-IR, HRI and LFI. Leptin levels were highest in patients with hepatic pre-steatosis. LAR was highest in the group with hepatic steatosis, but we did not observe significant correlations in relation to other parameters. Conclusion: VD levels are inversely associated with the degree of hepatic steatosis in overweight or obese paediatric patients. HOMA-IR inversely correlates with VD levels and positively with LFI. The LAR value was highest in the group of patients with steatosis, although we did not find out any significant correlations in relation to VD status and HRI. Key words: vitamin D – non-alcoholic fatty liver disease – insulin resistance – leptin – adiponectin – obesity – childhood


2021 ◽  
Vol 22 (8) ◽  
pp. 4156
Author(s):  
Yoshitaka Sakurai ◽  
Naoto Kubota ◽  
Toshimasa Yamauchi ◽  
Takashi Kadowaki

Many studies have reported that metabolic dysfunction is closely involved in the complex mechanism underlying the development of non-alcoholic fatty liver disease (NAFLD), which has prompted a movement to consider renaming NAFLD as metabolic dysfunction-associated fatty liver disease (MAFLD). Metabolic dysfunction in this context encompasses obesity, type 2 diabetes mellitus, hypertension, dyslipidemia, and metabolic syndrome, with insulin resistance as the common underlying pathophysiology. Imbalance between energy intake and expenditure results in insulin resistance in various tissues and alteration of the gut microbiota, resulting in fat accumulation in the liver. The role of genetics has also been revealed in hepatic fat accumulation and fibrosis. In the process of fat accumulation in the liver, intracellular damage as well as hepatic insulin resistance further potentiates inflammation, fibrosis, and carcinogenesis. Increased lipogenic substrate supply from other tissues, hepatic zonation of Irs1, and other factors, including ER stress, play crucial roles in increased hepatic de novo lipogenesis in MAFLD with hepatic insulin resistance. Herein, we provide an overview of the factors contributing to and the role of systemic and local insulin resistance in the development and progression of MAFLD.


Author(s):  
Ludovico Abenavoli ◽  
Anna C. Procopio ◽  
Emidio Scarpellini ◽  
Natale Polimeni ◽  
Isabella Aquila ◽  
...  

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