Introduction: Metabolic dysfunction–associated steatotic liver disease (MASLD) and metabolic dysfunction–associated alcohol‑related liver disease (MetALD) are increasingly recognized conditions worldwide. However, epidemiological data from Central and Eastern Europe are lacking.

Objectives: This study aimed to assess the prevalence, clinical profiles, and liver fibrosis burden of MASLD and MetALD in a representative population from Central and Eastern Europe.

Patients and methods: This study is part of the Bialystok PLUS (Polish Longitudinal University Study), an ongoing, prospective, population‑based cohort study. A random sample of 2456 adult residents from the city of Białystok, Poland, was analyzed. Anthropometric, epidemiological, clinical, and lifestyle‑related parameters were assessed. Participants were categorized into MASLD, MetALD, and control groups. Differences in metabolic comorbidities and liver fibrosis severity were evaluated between groups.

Results: The prevalence of MASLD was 22.72%, while MetALD accounted for 2.08% of the population. MASLD was predominantly associated with obesity and diabetes mellitus, whereas MetALD showed a higher prevalence of arterial hypertension and dyslipidemia. Significant liver fibrosis was more frequent in MetALD (17.8%) and MASLD (15.6%) compared to controls (5.1%; p <0.001 and p=0.005). The highest cirrhosis rates were observed in 4.44% of MetALD participants, 0.58% of MASLD participants, and 0.12% of controls (p=0.001). Risk factors for significant fibrosis were analyzed across subgroups.

Conclusions: MASLD and MetALD represent a substantial and distinct health burden not only in the Polish population but likely across Central and Eastern Europe, given shared epidemiological patterns of metabolic dysfunction and alcohol consumption. Understanding the interplay between these factors is crucial for improving diagnosis, treatment strategies, and public health policies in this region.