Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease characterized by excess fat accumulation in the liver. It is closely associated with metabolic syndrome, and patients with NAFLD often have comorbidities such as obesity, type 2 diabetes mellitus, and dyslipidemia. In addition to liver-related complications, NAFLD has been associated with a range of non-liver comorbidities, including cardiovascular disease, chronic kidney disease, and sleep apnea. Cardiovascular disease is the most common cause of mortality in patients with NAFLD, and patients with NAFLD have a higher risk of developing cardiovascular disease than the general population. Chronic kidney disease is also more common in patients with NAFLD, and the severity of NAFLD is associated with a higher risk of developing chronic kidney disease. Sleep apnea, a disorder characterized by breathing interruptions during sleep, is also more common in patients with NAFLD and is associated with the severity of NAFLD. The presence of non-liver comorbidities in patients with NAFLD has important implications for the management of this disease. Treatment of comorbidities such as obesity, type 2 diabetes mellitus, and dyslipidemia may improve liver-related outcomes in patients with NAFLD. Moreover, treatment of non-liver comorbidities may also improve overall health outcomes in patients with NAFLD. Therefore, clinicians should be aware of the potential for non-liver comorbidities in patients with NAFLD and should consider the management of these comorbidities as part of the overall management of this disease.

Nonalcoholic fatty liver disease (NAFLD) affects about a third of the world’s adult population and is a major public health concern. NAFLD is defined by the presence of hepatic steatosis and the absence of other causes of liver disease. As NAFLD is closely associated with the presence of the metabolic syndrome, several experts have called for a change in nomenclature from NAFLD to metabolic-associated fatty liver disease (MAFLD) to better reflect the underlying pathophysiology of NAFLD as a metabolically driven disease and shift to a “positive” diagnostic criteria rather than one of exclusion. Recent studies have suggested that the global prevalence of MAFLD is higher than that of NAFLD, and patients with MAFLD have more metabolic comorbidities compared to those with NAFLD. Emerging data also suggest that all-cause and cardiovascular mortality may be higher in MAFLD compared with NAFLD. In this synopsis, we discuss differences in clinical features, prevalence and clinical outcomes between NAFLD and MAFLD. In addition, we highlight the advantages and disadvantages of a name change from NAFLD to MAFLD from the perspective of the scientific community, care providers and patients.

Background/Aims: Due to increases in obesity and type 2 diabetes, the prevalence of nonalcoholic fatty liver disease (NAFLD) has also been increasing. Current forecast models may not include non-obese NAFLD. Here, we used the Bayesian approach to forecast the prevalence of NAFLD through the year 2040. Methods: Prevalence data from 245 articles involving 2,699,627 persons were used with a hierarchical Bayesian approach to forecast the prevalence of NAFLD through 2040. Subgroup analyses were performed for age, gender, presence of metabolic syndrome, region, and smoking status. Sensitivity analysis was conducted for clinical setting and study quality. Results: The forecasted 2040 prevalence was 55.7%, a three-fold increase since 1990 and a 43.2% increase from the 2020 prevalence of 38.9%. The estimated average yearly increase since 2020 was 2.16%. For those aged <50 years and ≥50 years, the 2040 prevalence were not significantly different (56.7% vs. 61.5%, P=0.52). There was a significant difference in 2040 prevalence by sex (males: 60% vs. 50%) but the trend was steeper for females (annual percentage change: 2.5% vs. 1.5%, P=0.025). There was no difference in trends overtime by region (P=0.48). The increase rate was significantly higher in those without metabolic syndrome (3.8% vs. 0.84%, P=0.003) and smokers (1.4% vs. 1.1%, P=0.011). There was no difference by clinical/community setting (P=0.491) or study quality (P=0.85). Conclusion By 2040, over half the adult population is forecasted to have NAFLD. The largest increases are expected to occur in women, smokers, and those without metabolic syndrome. Intensified efforts are needed to raise awareness of NAFLD and to determine long-term solutions addressing the driving factors of the disease.

The prevalence of non-alcoholic fatty liver disease (NAFLD) is estimated to be 25-30% of the population, and is the most common cause of elevated liver enzymes in Korea. NAFLD is a "hot potato" for pharmaceutical companies. Many clinical trials are underway to develop a first-in-class drug to treat NAFLD. However, there are several challenging issues regarding the diagnosis of NAFLD. Currently, liver biopsy is the gold standard method for the diagnosis of NAFLD and steatohepatitis. Ideally, globally recognized standards for histological diagnosis and methods to optimize observer agreement on biopsy interpretation should be developed. Liver biopsy is the best method rather than a perfect one. Recently, multi-parametric magnetic resonance imagery can estimate the amount of intrahepatic fat successfully and is widely used in clinical trials. But no diagnostic method can discriminate between steatohepatitis and simple steatosis. The other unresolved issue in regard to NAFLD is the absence of satisfactory treatment options. Vitamin E and obeticholic acid have shown protective effects in randomized controlled trials, but this drug has not been approved for use in Korea. This study will provide a description of diagnostic methods and treatments that are currently recommended for NAFLD.
Biomarkers/analysis ; Chenodeoxycholic Acid/analogs & derivatives/therapeutic use ; Clinical Trials as Topic ; Fatty Liver/diagnosis ; Fibrosis ; Humans ; Liver/diagnostic imaging/pathology ; Magnetic Resonance Imaging ; Non-alcoholic Fatty Liver Disease/*diagnosis/drug therapy ; Tomography, X-Ray Computed ; Ultrasonography ; Vitamin E/therapeutic use

Understanding of nonalcoholic fatty liver disease (NAFLD) continues to expand, but the relationship between race and ethnicity and NAFLD outside the use of cross-sectional data is lacking. Using longitudinal data, we investigated the role of race and ethnicity in adverse outcomes in NAFLD patients. Methods: Patients with NAFLD confirmed by imaging via manual chart review from any clinics at Stanford University Medical Center (1995–2021) were included. Primary study outcomes were incidence of liver events and mortality (overall and non-liver related). Results: The study included 9,340 NAFLD patients: White (44.1%), Black (2.29%), Hispanic (27.9%), and Asian (25.7%) patients. For liver events, the cumulative 5-year incidence was highest among White (19.1%) patients, lowest among Black (7.9%) patients, and similar among Asian and Hispanic patients (~15%). The 5-year and 10-year cumulative overall mortality was highest for Black patients (9.2% and 15.0%, respectively, vs. 2.5–3.5% and 4.3–7.3% in other groups) as well as for non-liver mortality. On multivariable regression analysis, compared to White patients, only Asian group was associated with lower liver-related outcomes (aHR: 0.83, P=0.027), while Black patients were at more than two times higher risk of both non-liver related (aHR: 2.35, P=0.010) and overall mortality (aHR: 2.13, P=0.022) as well as Hispanic patients (overall mortality: aHR: 1.44, P=0.022).Conclusions: Compared to White patients, Black patients with NAFLD were at the highest risk for overall and non-liver-related mortality, followed by Hispanic patients with Asian patients at the lowest risk for all adverse outcomes. Culturally sensitive and appropriate programs may be needed for more successful interventions.