Low alcohol consumption increases the risk of impaired glucose tolerance in patients with non-alcoholic fatty liver disease

The Loge GDR Was Strongly Associated with NAFLD as a Predictor in Normoalbuminuric Patients with Type 2 Diabetes

Aim

Attenuated insulin-sensitivity (IS) is a characteristic of type 2 diabetes (T2D) and is closely linked to non-alcoholic fatty liver disease (NAFLD). In recent years, many surrogate markers of IS have emerged to predict NAFLD. A natural log transformation of the glucose disposal rate (loge GDR) has been proposed as a new model for IS in patients with T2D. Our aim is to explore the correlation between loge GDR and NAFLD in normoalbuminuric patients with T2D.

Methods

A total of 1227 normoalbuminuric patients with T2D were involved in our study. NAFLD was evaluated by ultrasound. Biochemical and clinical data were collected, including parameters essential for calculating the loge GDR (triglycerides, urinary albumin-to-creatinine ratio, γ-glutamyl transferase and body mass index), as well as other relevant covariates required for adjustment. The relationship between the loge GDR and NAFLD was analyzed.

Results

NAFLD patients showed lower loge GDR values than non-NAFLD (P < 0.001). As the loge GDR tertiles increased, the prevalence of NAFLD was decreased (P < 0.001). Multivariate analysis displayed that loge GDR was independently corrected with NAFLD (OR: 0.084; 95% CI: 0.040-0.177). Furthermore, receiver operating characteristic (ROC) analysis showed that loge GDR (area under the curves: 0.797) was superior to other evaluation variables.

Conclusion

The loge GDR was strongly associated with NAFLD and might be a useful predictor in normoalbuminuric patients with T2D.

Longitudinal Outcomes Associated With Metabolic Dysfunction-Associated Steatotic Liver Disease: A Meta-analysis of 129 Studies

BACKGROUND & AIMS

The progression of metabolic dysfunction-associated steatotic liver disease (MASLD) has been found to manifest in a series of hepatic and extrahepatic complications. A comprehensive meta-analysis of the longitudinal outcomes associated with MASLD has yet to be conducted.

METHODS

To investigate the longitudinal outcomes associated with MASLD, Medline and Embase databases were searched to identify original studies that evaluated the longitudinal risks of incident clinical outcomes among MASLD patients compared with non-MASLD individuals. DerSimonian Laird random-effects meta-analysis was performed. Pooled effect estimates were calculated, and heterogeneity among studies was evaluated.

RESULTS

One hundred twenty-nine studies were included in the meta-analysis. Meta-analysis revealed a significant increase in the risk of cardiovascular outcomes (hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.27-1.60; P < .01), various metabolic outcomes such as incident hypertension (HR, 1.75; 95% CI, 1.46-2.08; P < .01), diabetes (HR, 2.56; 95% CI, 2.10-3.13; P < .01), pre-diabetes (HR, 1.69; 95% CI, 1.22-2.35; P < .01), metabolic syndrome (HR, 2.57; 95% CI, 1.13-5.85; P = .02), chronic kidney disease (HR, 1.38; 95% CI, 1.27-1.50; P < .01), as well as all cancers (HR, 1.54; 95% CI, 1.35-1.76; P < .01) among MASLD patients compared with non-MASLD individuals. By subgroup analysis, MASLD patients with advanced liver disease (HR, 3.60; 95% CI, 2.10-6.18; P < .01) were also found to be associated with a significantly greater risk (P = .02) of incident diabetes than those with less severe MASLD (HR, 1.63; 95% CI, 1.0-2.45; P = .02) when compared with non-MASLD.

CONCLUSIONS

The present study emphasizes the association between MASLD and its clinical outcomes including cardiovascular, metabolic, oncologic, and other outcomes. The multisystemic nature of MASLD found in this analysis requires treatment targets to reduce systemic events and end organ complications.

The bidirectional impacts of alcohol consumption and MAFLD for progressive fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), once considered a benign condition, has been associated with several cardiometabolic complications over the past two decades. The worldwide prevalence of NAFLD is as high as 30%. NAFLD requires the absence of a "significant alcohol intake." Conflicting reports have suggested that moderate alcohol consumption may be protective; therefore, the diagnosis of NAFLD previously relied on negative criteria. However, there has been a significant increase in alcohol consumption globally. Apart from the rise in alcohol-related liver disease (ARLD), alcohol, a major toxin, is associated with an increased risk of several cancers, including hepatocellular carcinoma. Alcohol misuse is a significant contributor to disability-adjusted life years. Recently, the term metabolic dysfunction-associated fatty liver disease (MAFLD) was proposed instead of NAFLD to include the metabolic dysfunction responsible for the major adverse outcomes in patients with fatty liver disease. MAFLD, dependent on the "positive diagnostic criteria" rather than previous exclusion criteria, may identify individuals with poor metabolic health and aid in managing patients at increased risk of all-cause and cardiovascular mortality. Although MAFLD is less stigmatizing than NAFLD, excluding alcohol intake may increase the risk of already existing underreported alcohol consumption in this subgroup of patients. Therefore, alcohol consumption may increase the prevalence of fatty liver disease and its associated complications in patients with MAFLD. This review discusses the effects of alcohol intake and MAFLD on fatty liver disease.

Alcohol and Metabolic-associated Fatty Liver Disease

The diagnosis of metabolic-associated fatty liver disease is based on the detection of liver steatosis together with the presence of metabolic dysfunction. According to this new definition, the diagnosis of metabolic-associated fatty liver disease is independent of the amount of alcohol consumed. Actually, alcohol and its metabolites have various effects on metabolic-associated abnormalities during the process of alcohol metabolism. Studies have shown improved metabolic function in light to moderate alcohol drinkers. There are several studies focusing on the role of light to moderate alcohol intake on metabolic dysfunction. However, the results from studies are diverse, and the conclusions are often controversial. This review systematically discusses the effects of alcohol consumption, focusing on light to moderate alcohol consumption, obesity, lipid and glucose metabolism, and blood pressure.

Low Levels of Alcohol Consumption, Obesity, and Development of Fatty Liver With and Without Evidence of Advanced Fibrosis

BACKGROUND AND AIMS

The effects of low-level alcohol consumption on fatty liver disease and the potential for effect modification by obesity is uncertain. We investigated associations among low-level alcohol consumption, obesity status, and the development of incident hepatic steatosis (HS), either with or without an increase in noninvasive liver fibrosis score category (from low to intermediate or high category).

APPROACH AND RESULTS

A total of 190,048 adults without HS and a low probability of fibrosis with alcohol consumption less than 30 g/day (men) and less than 20 g/day (women) were followed for up to 15.7 years. Alcohol categories of no, light, and moderate consumption were defined as 0, 1-9.9, and 10-29.9 g/day (10-19.9 g/day for women), respectively. HS was diagnosed by ultrasonography, and the probability of fibrosis was estimated using the fibrosis-4 index (FIB-4). Parametric proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). A total of 43,466 participants developed HS, 2,983 of whom developed HS with an increase in FIB-4 index (to intermediate or high scores). Comparing light drinkers and moderate drinkers with nondrinkers, multivariable-adjusted HRs (95% CI) for incident HS were 0.93 (0.90-0.95) and 0.90 (0.87-0.92), respectively. In contrast, comparing light drinkers and moderate drinkers with nondrinkers, multivariable-adjusted HRs (95% CI) for developing HS plus intermediate/high FIB-4 were 1.15 (1.04-1.27) and 1.49 (1.33-1.66), respectively. The association between alcohol consumption categories and incident HS plus intermediate/high FIB-4 was observed in both nonobese and obese individuals, although the association was stronger in nonobese individuals (P for interaction by obesity = 0.017).

CONCLUSIONS

Light/moderate alcohol consumption has differential effects on the development of different stages of fatty liver disease, which is modified by the presence of obesity.

Cardiovascular effects of alcohol: A double-edged sword / how to remain at the nadir point of the J-Curve?

BACKGROUND

In addition to its established harmful effects on the liver and other organs, heavy alcohol use confers deleterious effects on the cardiovascular (CV) system, as well. However, data have emerged that light/moderate alcohol consumption (1 drink/day for women and 1-2 drinks/day for men) may be protective against CV disease.

OBJECTIVE/METHODS

English articles regarding the CV effects of alcohol/ethanol were reviewed by search in Medline, Scopus, and Google Scholar.

RESULTS

A J-shaped curve has been proposed to illustrate a differential effect of alcohol on the CV system with the lowest point on the curve (light/moderate drinking) corresponding to optimal exposure to alcohol, which may confer cardioprotection, the rather neutral effect of non-drinking, and the highest risk of heavy and/or binge drinking reflecting the consequence of harmful exposure. However, staying at the nadir of this J-shaped curve appears difficult. Furthermore, concern and distrust have also been raised about the quality of evidence for such "cardioprotection", emphasizing the need for further randomized controlled trials. Another concern relates to the risk of moderate drinking leading to problem drinking, since alcohol is the most common addictive substance.

CONCLUSION

Optimal exposure to alcohol (light/moderate use) means that one needs to stay at the nadir of the J-shaped curve for alcohol use to avail oneself of possible cardioprotection, and this may not be an easy thing to accomplish and/or adhere to, especially if one "likes" alcohol drinking. However, the evidence of "cardioprotection" conferred by alcohol has also been refuted, due to lack of randomized controlled trials.

Moderate consumption of fermented alcoholic beverages diminishes diet-induced non-alcoholic fatty liver disease through mechanisms involving hepatic adiponectin signaling in mice

PURPOSE

Results of some epidemiological studies suggest that moderate alcohol consumption may be associated with a decreased risk to develop NAFLD. Here, the effect of the consumption of moderate beer and diluted ethanol, respectively, on the development of NAFLD were assessed.

METHODS

Female C57BL/6J mice were fed a control diet (C-D) or a diet rich in fructose, fat and cholesterol (FFC) enriched isocalorically and isoalcoholically with beer (FFC + B) or plain ethanol (FFC + E) (2.5 g ethanol/kg body weight/day) for 7 weeks. Liver damage was assessed by histology using NAFLD activity score. Markers of inflammation, insulin resistance and adiponectin signaling were measured at mRNA and protein levels. Using J774A.1 cells as a model of Kupffer cells, the effect of alcoholic beverages on adiponectin receptor 1 (Adipor1) was assessed.

RESULTS

Hepatic triglyceride concentration, neutrophil granulocytes, iNOS protein concentrations and early signs of insulin resistance found in FFC-fed mice were significantly attenuated in FFC+ B-fed mice (P < 0.05 for all). These findings were associated with a super-induction of Adipor1 mRNA expression (+ ~ 18-fold compared to all other groups) and a decrease of markers of lipid peroxidation in liver tissue of FFC + B-fed mice when compared to FFC-fed animals. Similar differences were not found between FFC- and FFC+ E-fed mice. Expression of Adipor1 was also super-induced (7.5-fold) in J774A.1 cells treated with beer (equivalent to 2 mmol/L ethanol).

CONCLUSIONS

These data suggest that moderate intake of fermented alcoholic beverages such as beer at least partially attenuates NAFLD development through mechanisms associated with hepatic AdipoR1 expression.

3-Acetyl-oleanolic acid ameliorates non-alcoholic fatty liver disease in high fat diet-treated rats by activating AMPK-related pathways

3-Acetyl-oleanolic acid (3Ac-OA) is a derivative of oleanolic acid (OA), which has shown therapeutic beneficial effects on diabetes and metabolic syndrome. In this study we investigated whether 3Ac-OA exerted beneficial effect on non-alcoholic fatty liver disease (NAFLD) in rats and its potential underlying mechanisms. Treatment with 3Ac-OA (1-100 μmol/L) dose-dependently decreased the intracellular levels of total cholesterol (TC) and triglyceride (TG) in FFA-treated primary rat hepatocytes and human HepG2 cell lines in vitro. Furthermore, oil red staining studies showed that 3Ac-OA caused dose-dependent decrease in the number of lipid droplets in FFA-treated primary rat hepatocytes. SD rats were fed a high fat diet (HFD) for 6 weeks and subsequently treated with 3Ac-OA (60, 30, 15 mg·kg^-1·d^-1) for 4 weeks. 3Ac-OA administration significantly decreased the body weight, liver weight and serum TC, TG, LDL-C levels in HFD rats. Furthermore, 3AcOA administration ameliorated lipid accumulation and cell apoptosis in the liver of HFD rats. Using adipokine array analyses, we found that the levels of 11 adipokines (HGF, ICAM, IGF-1, IGFBP-3, IGFBP-5, IGFBP-6, lipocalin-2, MCP-1, M-CSF, Pref-1 and RAGE) were increased by more than twofold in the serum of 3Ac-OA-treated rats, whereas ICAM, IGF-1 and lipocalin-2 had levels increased by more than 20-fold. Moreover, 3Ac-OA administration significantly increased the expression of glucose transporter type 2 (GLUT-2) and low-density lipoprotein receptor (LDLR), as well as the phosphorylation of AMP-activated protein kinase (AMPK), protein kinase B (AKT) and glycogen synthase kinase 3β (GSK-3β) in the liver tissues of HFD rats. In conclusion, this study demonstrates that 3Ac-OA exerts a protective effect against hyperlipidemia in NAFLD rats through AMPK-related pathways.

Consensus document. Management of non-alcoholic fatty liver disease (NAFLD). Clinical practice guideline

Non-alcoholic fatty liver disease (NAFLD) is the main cause of liver diseases in Spain and the incidence is raising due to the outbreak of type 2 diabetes and obesity. This CPG suggests recommendation about diagnosis, mainly non-invasive biomarkers, and clinical management of this entity. Life-style modifications to achieve weight loss is the main target in the management of NAFLD. Low caloric Mediterranean diet and 200 minutes/week of aerobic exercise are encouraged. In non-responders patients with morbid obesity, bariatric surgery or metabolic endoscopy could be indicated. Pharmacological therapy is indicated in patients with NASH and fibrosis and non-responders to weight loss measures. NAFLD could influence liver transplantation, as a growing indication, the impact of steatosis in the graft viability, de novo NAFLD rate after OLT and a raised cardiovascular risk that modify the management of this entity. The current CPG was the result of the First Spanish NAFLD meeting in Seville.

Light alcohol consumption has the potential to suppress hepatocellular injury and liver fibrosis in non-alcoholic fatty liver disease

Background & aims

The modest consumption of alcohol has been reported to decrease the incidence of fatty liver or prevalence of steatohepatitis. In this study, we investigated the effect of light alcohol consumption on liver function and gene expression in patients with non-alcoholic fatty liver disease (NAFLD).

Methods

The study group was formed of 178 patients diagnosed with non-alcoholic fatty liver disease, subclassified into two groups for analysis based on the daily alcohol consumption: non-alcohol group and light alcohol consumer group (≤20 g of ethanol/day). Clinical characteristics, liver histological features, gene expression, comprehensively analyzed using microarrays (BRB-Array tools), and molecular network were evaluated and compared between the two groups.

Results

No significant differences in steatosis or inflammation score were noted among the groups. However, the ballooning and fibrosis scores were significantly lower in the light alcohol consumer group than in the non-alcohol group. Gene expression analysis revealed a marked inhibition of the pathways involved in the immune response in the light alcohol group compared to that in the non-alcohol group.

Conclusions

Light alcohol consumption might suppress activity of non-alcoholic steatohepatitis by reducing gene expression levels involved in the immune response. This inhibition in gene expression was associated with a lowering of liver fibrosis and hepatocellular injury.

Longitudinal study of alcohol consumption and HDL concentrations: a community-based study

Background: In cross-sectional studies and short-term clinical trials, it has been suggested that there is a positive dose-response relation between alcohol consumption and HDL concentrations. However, prospective data have been limited.Objective: We sought to determine the association between total alcohol intake, the type of alcohol-containing beverage, and the 6-y (2006-2012) longitudinal change in HDL-cholesterol concentrations in a community-based cohort.Design: A total of 71,379 Chinese adults (mean age: 50 y) who were free of cardiovascular diseases and cancer and did not use cholesterol-lowering agents during follow-up were included in the study. Alcohol intake was assessed via a questionnaire in 2006 (baseline), and participants were classified into the following categories of alcohol consumption: never, past, light (women: 0-0.4 servings/d; men: 0-0.9 servings/d), moderate (women: 0.5-1.0 servings/d; men: 1-2 servings/d), and heavy (women: >1.0 servings/d; men: >2 servings/d). HDL-cholesterol concentrations were measured in 2006, 2008, 2010, and 2012. We used generalized estimating equation models to examine the associations between baseline alcohol intake and the change in HDL-cholesterol concentrations with adjustment for age, sex, smoking, physical activity, obesity, hypertension, diabetes, liver function, and C-reactive protein concentrations.Results: An umbrella-shaped association was observed between total alcohol consumption and changes in HDL-cholesterol concentrations. Compared with never drinkers, past, light, moderate, and heavy drinkers experienced slower decreases in HDL cholesterol of 0.012 mmol · L^-1 · y^-1 (95% CI: 0.008, 0.016 mmol · L^-1 · y^-1), 0.013 mmol · L^-1 · y^-1 (95% CI: 0.010, 0.016 mmol · L^-1 · y^-1), 0.017 mmol · L^-1 · y^-1 (95% CI: 0.009, 0.025 mmol · L^-1 · y^-1), and 0.008 mmol · L^-1 · y^-1 (95% CI: 0.005, 0.011 mmol · L^-1 · y^-1), respectively (P < 0.0001 for all), after adjustment for potential confounders. Moderate alcohol consumption was associated with the slowest increase in total-cholesterol:HDL-cholesterol and triglyceride:HDL-cholesterol ratios. We observed a similar association between hard-liquor consumption and the HDL-cholesterol change. In contrast, greater beer consumption was associated with slower HDL-cholesterol decreases in a dose-response manner.Conclusion: Moderate alcohol consumption was associated with slower HDL-cholesterol decreases; however, the type of alcoholic beverage had differential effects on the change in the HDL-cholesterol concentration.

Effects of alcohol on c-Myc protein in the brain

Alcoholism is a disorder categorized by significant impairment that is directly related to persistent and extreme use of alcohol. The effects of alcoholism on c-Myc protein expression in the brain have been scarcely studied. This is the first study to investigate the role different characteristics of alcoholism have on c-Myc protein in the brain. We analyzed c-Myc protein in the hypothalamus and amygdala from five different animal models of alcohol abuse. c-Myc protein was increased following acute ethanol exposure in a mouse knockout model and following chronic ethanol consumption in vervet monkeys. We also observed increases in c-Myc protein exposure in animals that are genetically predisposed to alcohol and methamphetamine abuse. Lastly, c-Myc protein was increased in animals that were acutely exposed to methamphetamine when compared to control treated animals. These results suggest that in substance abuse c-Myc plays an important role in the brain's response.