What Do We Know about Inequalities in NAFLD Distribution and Outcomes? A Scoping Review

Abstract

With prevalence high and rising given the close relationship with obesity and diabetes mellitus, non-alcoholic fatty liver disease (NAFLD) is progressively becoming the most common chronic liver condition worldwide. However, little is known about the health inequalities in NAFLD distribution and outcomes. This review aims to analyze health inequalities in NAFLD distribution globally and to assess the health disparities in NAFLD-related outcomes. We conducted a scoping review of global health inequalities in NAFLD distribution and outcomes according to gender/sex, ethnicity/race, and socioeconomic position from PubMed’s inception to May 2021. Ultimately, 20 articles were included in the review, most (75%) of them carried out in the United States. Males were found to have a higher NAFLD prevalence (three articles), while available evidence suggests that women have an overall higher burden of advanced liver disease and complications (four articles), whereas they are less likely to be liver-transplanted once cirrhosis develops (one article). In the US, the Hispanic population had the highest NAFLD prevalence and poorer outcomes (seven articles), whereas Whites had fewer complications than other ethnicities (two articles). Patients with low socioeconomic status had higher NAFLD prevalence (four articles) and a higher likelihood of progression and complications (five articles). In conclusion, globally there is a lack of studies analyzing NAFLD prevalence and outcomes according to various axes of inequality through joint intersectional appraisals, and most studies included in our review were based on the US population. Available evidence suggests that NAFLD distribution and outcomes show large inequalities by social group. Further research on this issue is warranted.

Worldwide long-term trends in the incidence of nonalcoholic fatty liver disease during 1990–2019: A joinpoint and age-period-cohort analysis

“…Strengthening education and communication, raising public awareness, and developing sound disease classification criteria and long-term prevention plans (including for obesity and type 2 diabetes) are urgent priorities for Latin America to address their challenges with NAFLD ( 47 , 48 ). NAFLD is a multifactorial disorder influenced by individual behaviors and genetics, as well as cultural, demographic, economic, medical, and environmental influences ( 49 ). The recent diet trends of excessive energy intake and sedentary lifestyles, and unbalanced medical resources can somewhat explain the differences among the five SDI subgroups ( 50 , 51 ).…”

Applying an equity lens to liver health and research in Europe

“…As for NAFLD, in a previous study 15 we found that very few studies investigating socioeconomic determinants of health and inequality on NAFLD had been published, almost all of them in the US, where Hispanic ethnicity has been associated with a higher prevalence of NAFLD and poorer outcomes and female sex has been associated with a lower chance of receiving a liver transplant once cirrhosis develops. Moreover, low socioeconomic status was associated with a higher NAFLD prevalence (4 articles) and a higher likelihood of progression and complications.…”

“…Patients with low socioeconomic status had higher NAFLD prevalence and a higher likelihood of progression and complications. 15 Educational programmes delivered at schools on the harms of a sedentary lifestyle on fat-rich sugar-rich diets, including a clear portrayal of obesity as a disease. Obesity should be tackled by community health programmes in which parents are engaged.…”

Non-alcoholic fatty liver disease (NAFLD) and mental illness: Mechanisms linking mood, metabolism and medicines

“…NAFLD/NASH prevalence is epidemiologically linked to multiple social determinants of health, including poverty, food or housing insecurity, and poor access to healthcare ( Talens et al, 2021 ). Patients experiencing poor determinants of health also have a higher prevalence of NAFLD-associated traits including insulin resistance, obesity, and metabolic syndrome ( Cho et al, 2021 ).…”