Liver and Bile
J Hepatol. 2024;80(5):694–701
Clinical profiles and mortality rates are similar for metabolic dysfunction-associated steatotic liver disease and non-alcoholic fatty liver disease
Background and aims: Recently, the term metabolic dysfunction-associated steatotic liver disease (MASLD) has replaced non-alcoholic fatty liver disease (NAFLD). Concern remains regarding whether the evidence generated under the NAFLD definition can be used for MASLD. The authors compared the clinical profile and outcomes of NAFLD to MASLD using tertiary care- and population-based data.
Methods: Comparison data were obtained from their NAFLD database and the National Health and Nutrition Examination Survey (NHANES III). Clinical profiles and non-invasive tests (enhanced liver fibrosis [ELF] score, fibrosis-4 index [FIB-4] and vibration-controlled transient elastography) were compared. Mortality data were obtained from NHANES-National Death Index. All-cause mortality was assessed by Cox proportional hazards regression models and cause-specific mortality by competing risk analysis.
Results: There were 6429 patients in the NAFLD database (age, 54 ± 12 years, 42% male, body mass index [BMI] 35.4 ± 8.3, waist circumference 112 ± 17 cm, 52% type 2 diabetes). Average scores for ELF, FIB-4 and liver stiffness were 9.6 ± 1.2, 1.69 ± 1.24, 14.0 ± 11.8 kPa, respectively; 99% met MASLD criteria; 95% met MASLD on BMI only. Predictive accuracy of ELF and FIB-4 were identical between MASLD and NAFLD. 12,519 eligible participants from NHANES were included (age, 43.00 years, 47.38% male, 22.70% obese, 7.28% type 2 diabetes, 82.51% ≥ 1 cardiometabolic criteria). Among the NHANES study population, there was excellent concordance between MASLD and NAFLD diagnoses: Cohen’s kappa coefficient: 0.968 (95% confidence interval: 0.962–0.973) with 5.29% of NAFLD cases not meeting MASLD criteria. After a median follow-up of 22.83 years, there were no mortality differences between MASLD and NAFLD diagnoses (p values ≥ 0.05).
Conclusions: Non-alcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated steatotic liver disease (MASLD) are similar except individuals with MASLD seem to be older with slightly higher mortality risk, likely owing to cardiometabolic risk factors. Clinical profiles and non-invasive test thresholds were also identical. These data provide evidence that NAFLD and MASLD terminologies can be used interchangeably. For the small proportion of patients with NAFLD who do not meet MASLD criteria, further consideration is needed.