WASHINGTON – Nonalcoholic fatty liver disease (NAFLD) is a complex disease that involves multiple systems, and several standout abstracts at the annual meeting of the American Association for the Study of Liver Diseases emphasized the importance of multisystem management and the potential of combination therapies, Kymberly D. Watt, MD, said during the final debrief.
“The actual underlying mechanisms and the underlying processes that are going on are way more complicated than just inflammation and scarring,” said Dr. Watt, associate professor of medicine and medical director of liver transplantation at the Mayo Clinic, Rochester, Minn. “We have numerous areas to target, including insulin resistance, lipid metabolism, oxidative stress, inflammation, immune modulation, cell death, etc.”
She noted several studies that evaluated the prevalence of NAFLD, including a study that found that “about one-third of patients walking through the door of the clinic had nonalcoholic steatohepatitis [NASH],” suggesting physicians should consider screening at-risk patients (abstract 58). A Korean study found about 18% of asymptomatic lean individuals (body mass index less than 23 kg/m2) had NAFLD and identified sarcopenia as a significant risk factor for NAFLD in these lean patients (abstract 59). “Sarcopenia is something that we really need to pay a lot more attention to,” Dr. Watt said.
Other studies better outlined the increasing association between NAFLD and hepatocellular carcinoma, Dr. Watt noted (abstracts 2119 and 2102). Another study confirmed that men with NAFLD/NASH have almost twice the incidence of hepatocellular carcinoma (HCC) as women — 0.43%-0.5% vs. 0.22%-0.28%, with both groups significantly higher than the general population (abstract 2116). “And looking further, we can actually quote an HCC incidence in NASH of 0.009%,” she added.
Again emphasizing the multisystem impact of NAFLD, Dr. Watt cited a study that calculated the cardiovascular risks incumbent with liver disease. Researchers reported that men and women at the time of NAFLD diagnosis had significantly higher rates of either angina/ischemic heart disease or heart failure (abstract 55). Women, specifically, had a higher risk for cardiovascular events earlier than men and overall are at equal risk to men, unlike in the general population where women are at lower risk. “We need to start looking at screening and prevention of other diseases in our patients with NASH,” Dr. Watt said. “In addition, we need to be more aware of the elevated risk in these patients and not just approach them in the same way as the general population.”
Physicians may be tempted to discontinue statin therapy in patients with chronic liver disease, but Dr. Watt cited a poster that showed that this results in worse outcomes (abstract 2106). The researchers found that continued statin use was associated with a lower risk of death with compensated and decompensated liver function. “These data help to educate certain patients of their risk of decompensation over time,” Dr. Watt said.
An international study determined that the severity of advanced compensated liver disease is a key determinant in outcomes, finding that those with bridging fibrosis are at greater risk of vascular events, but those with cirrhosis and Child-Turcotte-Pugh A5 and A6 disease have much higher risks of hepatic decompensation and HCC out to 14 years (abstract 60). “The reason to look at these is to be able to tell your patients that they probably have a 30% increased risk of decompensation by 4 years,” Dr. Watt said.
Dr. Watt pointed out three studies that shed more light on important biomarkers of NAFLD. One study reported that three biomarkers – alpha-2-macroglobulin, hyaluronic acid, and tissue inhibitor of metalloproteinase-1 – have a high sensitivity for differentiating low-stage and stage F3-F4 disease (abstract 95). Another study found that a measure using Pro-C3 and other clinical markers were predictive of F3 or F4 fibrosis in NAFLD (abstract 93). And, other researchers found that a HepQuant-STAT measure of greater than 0.50 microM in patients who ingested deuterated cholic acid (d4-CA) solution may be a minimally invasive alternative to biopsy for diagnosing NASH (abstract 96).
Management studies focusing on varying targets were also presented. A trial of fibroblast growth factor–21 for treatment of NAFLD found that patients in the 10- and 20-mg dose arms showed improvement in MRI hepatic fat fraction, ALT, AST, and liver stiffness at 16 weeks vs. placebo. A few patients had some mild elevation to their liver enzymes on treatment (abstract 182). “So I think we need to remain cautious and watch these patients closely, but overall it seems to be reasonably safe data,” she said. Another drug trial of the acetyl-CoA carboxylase inhibitor GS-0976 also showed promise for overall improvement in MRI steatosis measures (abstract LB-9).
Three preclinical studies of dual-agent therapies in animals have demonstrated improvement in inflammatory and fibrosis scores, Dr. Watt noted (abstracts 2,000, 2,002 and 2,052). “There’s no one drug that’s going to be likely the magic cure,” Dr. Watt said. “There will likely be a lot more focus and data coming out on dual-action agents.” Another animal study addressed the burning question if decaffeinated coffee has the same protective effect against NASH as caffeinated coffee (abstract 2093). Said Dr. Watt: “If you are interested in the potential benefits of coffee but really can’t handle the caffeine, this study suggests, you may still be OK.”
Finally, Dr. Watt noted an early study of three-dimensional printing has shown potential for replicating NASH tissue for bench studies (abstract 1963). “3-D printing is certainly a wave of the future,” she said, pointing out that researchers have created a 3-D model that has some metabolic equivalency to NASH, with the inflammatory cytokine release, hepatic stellate cell activation, “and all of the features that we see in NASH. This may be of potential use down the road to avoid relying on animal models in preclinical studies.”
The Liver Meeting next convenes Nov. 9-13, 2018, in San Francisco.
Dr. Watt disclosed ties to Bristol-Myers Squibb, Exelixis, and Seattle Genetics.