Prevalence of fatty liver disease risk factors varies by ethnicity, region

WASHINGTON — Independent risk factors and prevalence of risk factors related to the development of fatty liver disease vary among ethnicities and regional location, according to a presenter at Emerging Trends in Non-Alcoholic Fatty Liver Disease.

“There are people from the public health world who would argue that there is a lot of fearmongering going on; many people may not need liver directed therapy because there are competing risks in this population and cardiovascular risk is ... still the leading cause of mortality in this population,” Arun J. Sanyal, MD, FAASLD, of the division of gastroenterology at Virginia Commonwealth University, said. “A big part of what we struggle with is, at a population level, how do we target those who are going to need therapy? For that, one of the things that we really need to have a better understanding of are the racial and ethnic differences in terms of the risk of developing liver disease, risk of progression, disease modifiers, treatment outcomes, treatment outcome modifiers and treatment response modifiers.”

General risk factors for developing fatty liver disease include high-carb and high-fat diet, sedentary lifestyle and socioeconomic status. “Diet and lifestyle are also very important, because across different ethnicities, the dietary composition and what people consume on a daily basis is actually quite different,” Sanyal said.

According to data presented by Sanyal, Hispanic people have a higher prevalence of developing fatty liver disease compared with white and black people. In Asian populations, the high prevalence of diabetes is an independent risk factor for fatty liver disease. Approximately 30% of adults in India reportedly had excess fat in their liver and, in this population, rural residents had a lower prevalence of fatty liver compared with individuals living in urban areas.

South Asian populations — including lean individuals — have a higher prevalence of insulin resistance compared with white people, as this population has increased visceral adipose tissue that is more susceptible to inflammation, can drive a systemic inflammatory state and has been linked to diabetes, cardiovascular disease and increased prevalence of liver disease.

In a retrospective study of 430 patients from France (n = 96), Brazil (n = 125), India (n = 63) and the United States (n = 139), prevalence of diabetes, insulin sensitivity and histologic severity differed among all cohorts and varied among lean patients, overweight patients and obese patients. The prevalence of type 2 diabetes was low in the lean French patients, high in the lean Brazilian patients, and intermediate in the patients from the United States and India.

The researchers observed insulin sensitivity in all BMI categories in the U.S. patients. Insulin sensitivity worsened progressively in the higher BMI categories in the French patients and was high in the Brazilian cohort, split between 40% of patients who were insulin sensitive and 60% who had severe insulin resistance. In India, lean and obese patients had similar insulin sensitivity.

“We clearly need a lot more work with prospective data in larger cohorts to really get a better understanding of these differences, not only in terms of how the histology develops but actually how the disease progresses,” Sanyal said. “There are still major gaps, which is an agenda for research, in terms of rates of development of disease across these different populations, interaction with socioeconomic status, rates of progression, factors driving the progression, and the therapeutic responses across these different groups. And hopefully some of these large pivotal trials that are currently being done will address at least some of the therapeutic responses questions.” – by Talitha Bennett

Reference:

Sanyal AJ. Racial and Ethnic Differences in Non-Alcoholic Fatty Liver Disease. Presented at: Emerging Trends in Non-Alcoholic Fatty Liver Disease; March 18-19, 2017; Washington.

Disclosure: Sanyal reports he is an advisor for Abbott, Bristol-Myers Squibb, Exhalenz, Genefit, Gilead, Ikaria, Novartis, Pfizer, Tiziana, Conatus, OWL, Echosens and Immuron; and is a consultant for Echosens, Enanta, Exhalenz, Genentech, Hemoshear, Immuron, Islet Sciences, JD Pharma, Merck, Nimbus, Salix, Takeda, Zafgen, Amarin, Vivelyx, Malinckrodt, Ardelyx, Indalo and Zydus.