Clinical characteristics and mortality outcomes associated with subtypes of steatotic liver disease in the United States

Background In 2023, experts from the European and American regions proposed the concepts of steatotic liver disease (SLD) and metabolic dysfunction-associated steatotic liver disease (MASLD). MASLD was proposed as a replacement for NAFLD. We compared the long-term outcomes of patients with various subtypes of SLD and participants with the various combinations of MASLD and NAFLD definitions. Methods We conducted a retrospective study using the NHANESIII database. Cox proportional risk models were used to study the all-cause mortality and mortality from specific causes of patients with subtypes of SLD, MASLD, and NAFLD. Results During a follow-up period of 31 years (median 25 years), the adjusted risks of all-cause death for patients with MASLD was 1.14 (95% confidence interval [CI] 1.01-1.29; P =0.04) vs . the non-SLD group. There was a high level of consistency between MASLD and NAFLD (Cohen’s kappa coefficient of 0.62545 ± 0.0175). Advanced fibrosis was the most serious risk factor for all-cause mortality in MASLD, and high C-reactive protein concentration was the most serious risk factor for all-cause mortality in NAFLD, followed by type 2 diabetes. Conclusions MASLD is associated with a higher risk of all-cause mortality, which is not related to the demographics or metabolic characteristics of patients.Our research findings further support that MASLD is a pathological disease related to liver disease itself. Therefore, redefining NAFLD as metabolic dysfunction related fatty liver disease (MAFLD) may help improve our understanding of predictive factors that increase the risk of death.