The bidirectional impacts of alcohol consumption and the metabolic syndrome: Cofactors for progressive fatty liver disease

Insights into the Epidemiology, Pathogenesis, and Therapeutics of Nonalcoholic Fatty Liver Diseases

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease which affects ≈25% of the adult population worldwide, placing a tremendous burden on human health. The disease spectrum ranges from simple steatosis to steatohepatitis, fibrosis, and ultimately, cirrhosis and carcinoma, which are becoming leading reasons for liver transplantation. NAFLD is a complex multifactorial disease involving myriad genetic, metabolic, and environmental factors; it is closely associated with insulin resistance, metabolic syndrome, obesity, diabetes, and many other diseases. Over the past few decades, countless studies focusing on the investigation of noninvasive diagnosis, pathogenesis, and therapeutics have revealed different aspects of the mechanism and progression of NAFLD. However, effective pharmaceuticals are still in development. Here, the current epidemiology, diagnosis, animal models, pathogenesis, and treatment strategies for NAFLD are comprehensively reviewed, emphasizing the outstanding breakthroughs in the above fields and promising medications in and beyond phase II.

A Designer Synbiotic Attenuates Chronic-Binge Ethanol-Induced Gut-Liver Injury in Mice

Gut dysbiosis and altered short-chain fatty acids are associated with ethanol-induced liver injury. SCFA are fermentation byproducts of the gut microbiota known to have many beneficial biological effects. We tested if a designer synbiotic could protect against ethanol-induced gut-liver injury. C57BL/6 female mice were exposed to chronic-binge ethanol feeding consisting of ethanol (5% vol/vol) for 10 days, followed by a single gavage (5 g/kg body weight) 6 h before euthanasia. A group of mice also received oral supplementation daily with a designer synbiotic, and another group received fecal slurry (FS); control animals received saline. Control mice were isocalorically substituted maltose dextran for ethanol over the entire exposure period. Ethanol exposure reduced expression of tight junction proteins in the proximal colon and induced hepatocyte injury and steatosis. Synbiotic supplementation not only mitigated losses in tight junction protein expression, but also prevented ethanol-induced steatosis and hepatocyte injury. Ethanol exposure also increased hepatic inflammation and oxidative stress, which was also attenuated by synbiotic supplementation. Mice receiving FS were not protected from ethanol-induced liver injury or steatosis. Results were associated with luminal SCFA levels and SCFA transporter expression in the proximal colon and liver. These results indicate supplementation with a designer synbiotic is effective in attenuating chronic-binge ethanol-induced gut-liver injury and steatosis in mice, and highlight the beneficial effects of the gut microbial fermentation byproducts.

Serum Zinc Levels in Hidradenitis Suppurativa: A Case-Control Study

BACKGROUND

Serum zinc levels in patients with hidradenitis suppurativa (HS) have not been previously studied.

OBJECTIVE

The aim was to investigate the association between HS and serum zinc levels.

METHODS

A multicenter, prospective clinical and analytical case-control study was designed to assess the possible association between HS and serum zinc levels. Consecutive patients with moderate or severe HS (Hurley II or III exclusively) were enrolled. A control population was recruited from primary care clinics. Fasting blood samples were extracted from each patient and serum zinc levels determined. Candidate predictors for low serum zinc levels were determined using logistic regression models.

RESULTS

In total, 122 patients with HS and 122 control subjects were studied. Of the 122 HS patients, 79 (64.8%) were Hurley II and 43 (35.2%) were Hurley III. Low serum zinc levels (≤ 83.3 µg/dL) were more prevalent in HS (adjusted odds ratio [ORa] 6.7, P < 0.001). After logistic regression analysis, low serum zinc levels were associated with Hurley III (ORa 4.4, P < 0.001), Dermatology Life Quality Index ≥ 9 (ORa 3.1, P = 0.005), number of affected sites ≥ 3 (ORa 2.4, P = 0.042), genital location (ORa 2.9, P = 0.009), and perineal location (ORa 2.5, P = 0.025).

CONCLUSION

Low serum zinc levels are more prevalent in HS than in a healthy population, an indicator that may also be associated with disease severity.

Alcoholic liver disease

Alcoholic liver disease (ALD) is the most prevalent type of chronic liver disease worldwide. ALD can progress from alcoholic fatty liver (AFL) to alcoholic steatohepatitis (ASH), which is characterized by hepatic inflammation. Chronic ASH can eventually lead to fibrosis and cirrhosis and in some cases hepatocellular cancer (HCC). In addition, severe ASH (with or without cirrhosis) can lead to alcoholic hepatitis, which is an acute clinical presentation of ALD that is associated with liver failure and high mortality. Most individuals consuming >40 g of alcohol per day develop AFL; however, only a subset of individuals will develop more advanced disease. Genetic, epigenetic and non-genetic factors might explain the considerable interindividual variation in ALD phenotype. The pathogenesis of ALD includes hepatic steatosis, oxidative stress, acetaldehyde-mediated toxicity and cytokine and chemokine-induced inflammation. Diagnosis of ALD involves assessing patients for alcohol use disorder and signs of advanced liver disease. The degree of AFL and liver fibrosis can be determined by ultrasonography, transient elastography, MRI, measurement of serum biomarkers and liver biopsy histology. Alcohol abstinence achieved by psychosomatic intervention is the best treatment for all stages of ALD. In the case of advanced disease such as cirrhosis or HCC, liver transplantation may be required. Thus, new therapies are urgently needed.

Practical Diagnosis and Staging of Nonalcoholic Fatty Liver Disease: A Narrative Review

As the rates of obesity increase worldwide, the prevalence of nonalcoholic fatty liver disease (NAFLD) has risen and it is now the most common cause of liver disease in the developed world. A significant proportion of patients with NAFLD develop nonalcoholic steatohepatitis and progressive liver fibrosis, which can lead to cirrhosis and its complications. NAFLD should be suspected in individuals who have central obesity and metabolic risk factors. A diagnosis of NAFLD can be made when patients have evidence of steatosis on imaging or if they have raised liver enzymes with a background of metabolic risk factors, provided other causes of liver disease and excessive alcohol consumption are excluded. Making a specific diagnosis of NAFLD is important so that affected individuals can receive specific treatment and be monitored for its complications. The stage of liver fibrosis is the most important prognostic factor so must be assessed in all patients; a number of simple blood tests and imaging modalities allow accurate fibrosis staging without the need for liver biopsy. The aim of this narrative review is to provide a practical overview relating to the diagnosis and staging of NAFLD using noninvasive tests that are widely available in primary and secondary care.