Assessment and management of comorbidities (including cardiovascular disease) in patients with nonalcoholic fatty liver disease

Extracellular vesicles derived from fat-laden hepatocytes undergoing chemical hypoxia promote a pro-fibrotic phenotype in hepatic stellate cells

BACKGROUND

The transition from steatosis to non-alcoholic steatohepatitis (NASH) is a key issue in non-alcoholic fatty liver disease (NAFLD). Observations in patients with obstructive sleep apnea syndrome (OSAS) suggest that hypoxia contributes to progression to NASH and liver fibrosis, and the release of extracellular vesicles (EVs) by injured hepatocytes has been implicated in NAFLD progression.

AIM

To evaluate the effects of hypoxia on hepatic pro-fibrotic response and EV release in experimental NAFLD and to assess cellular crosstalk between hepatocytes and human hepatic stellate cells (LX-2).

METHODS

HepG2 cells were treated with fatty acids and subjected to chemically induced hypoxia using the hypoxia-inducible factor 1 alpha (HIF-1α) stabilizer cobalt chloride (CoCl2). Lipid droplets, oxidative stress, apoptosis and pro-inflammatory and pro-fibrotic-associated genes were assessed. EVs were isolated by ultracentrifugation. LX-2 cells were treated with EVs from hepatocytes. The CDAA-fed mouse model was used to assess the effects of intermittent hypoxia (IH) in experimental NASH.

RESULTS

Chemical hypoxia increased steatosis, oxidative stress, apoptosis and pro-inflammatory and pro-fibrotic gene expressions in fat-laden HepG2 cells. Chemical hypoxia also increased the release of EVs from HepG2 cells. Treatment of LX2 cells with EVs from fat-laden HepG2 cells undergoing chemical hypoxia increased expression pro-fibrotic markers. CDAA-fed animals exposed to IH exhibited increased portal inflammation and fibrosis that correlated with an increase in circulating EVs.

CONCLUSION

Chemical hypoxia promotes hepatocellular damage and pro-inflammatory and pro-fibrotic signaling in steatotic hepatocytes both in vitro and in vivo. EVs from fat-laden hepatocytes undergoing chemical hypoxia evoke pro-fibrotic responses in LX-2 cells.

Real-world comorbidities and treatment patterns among patients with non-alcoholic fatty liver disease receiving phosphatidylcholine as adjunctive therapy in Russia

Objective

Previous research conducted in Russia showed that the number of patients with non-alcoholic fatty liver disease (NAFLD) and associated metabolic comorbidities is large. We conducted an observational study to describe the management of NAFLD in patients with metabolic syndrome in Russia.

Design

A total of 2843 adult patients from 174 medical sites across 6 federal districts of Russia with newly diagnosed NAFLD, who had at least one of four comorbidities, namely overweight/obesity, hypertension, type 2 diabetes mellitus, and hypercholesterolaemia, and who received phosphatidylcholine (PPC) as an adjunctive treatment to standard care, were enrolled during 2015-2016.

Results

Overall, 2263 patients (79.6%) had at least two metabolic comorbidities associated with NAFLD; overweight/obesity was the most common comorbidity reported in 2298 patients (80.8%). Simple steatosis was the most frequently identified clinical form of NAFLD, diagnosed in 2128 patients (74.9%). Among hypertensive patients, ACE inhibitors, statins, and sartans were most commonly prescribed. Biguanides were administered in more than half of diabetic patients. In patients with overweight/obesity and hypercholesterolaemia, statins were the most frequently prescribed medications. Almost all patients (2837/2843; 99.8%) were treated with 1.8 g of PPC three times per day. PPC therapy was associated with a 90.5% 6-month compliance rate, high treatment satisfaction, and a favourable safety profile. However, almost 15% of diabetic patients and 40% of overweight/obese patients received no further treatment.

Conclusions

In Russia, patients with newly diagnosed NAFLD represent a population heavily burdened by comorbidities, mainly overweight/obesity and hypercholesterolaemia. A significant part of these patients did not receive a comprehensive pharmacotherapy, highlighting the existing unmet need in the current management of NAFLD patients with metabolic syndrome in Russia.