Low-to-moderate alcohol consumption is associated with increased fibrosis in individuals with metabolic dysfunction-associated steatotic liver disease.

BACKGROUND & AIMS: Both metabolic dysfunction and alcohol consumption cause steatotic liver disease (SLD). New nomenclature and distinction of metabolic dysfunction-associated SLD (MASLD) and MetALD categories is based on arbitrary thresholds of alcohol intake. We assessed the impact of different levels of alcohol consumption on SLD severity and its interaction with metabolic comorbidities. METHODS: Population-based study with transient elastography (FibroScan®) data from participants in Spain (derivation) and U.S. (validation) cohorts. Controlled attenuation parameter (CAP≥275 dB/m) identified SLD. At least one cardiometabolic risk factor was required to define MASLD. Among MASLD patients, low alcohol consumption was defined as an average of 5-9 drinks/week, moderate consumption as 10-13 drinks/week for females and 10-20 drinks/week for males, and increased alcohol intake (MetALD) as 14-35 drinks/week for females and 21-42 drinks/week for males. Significant fibrosis was defined as LSM≥8 kPa and at-risk MASH as FAST score≥0.35. RESULTS: The derivation cohort included 2,227 subjects with MASLD (9% reported low, 14% moderate alcohol consumption), and 76 cases with MetALD. Overall prevalence of significant fibrosis and at-risk MASH were 7.6% and 14.8%, respectively. In the multivariable analysis, alcohol consumption was independently associated with significant fibrosis and at-risk MASH. A dose-dependent increase in the prevalence of significant fibrosis and at-risk MASH was observed between the number of drinks/week and the number of cardiometabolic factors. The validation cohort included 1,732 participants with MASLD, of whom 17% had significant fibrosis and 13% at-risk MASH. This cohort validated the association between moderate intake and MASLD at risk of progression (OR=1.69 [95%CI 1.06-2.71]). CONCLUSIONS: Moderate alcohol intake is commonly seen in MASLD and increases the risk of advanced disease, in a similar magnitude to MetALD spectrum. IMPACT AND IMPLICATIONS: Metabolic risk factors such as overweight, diabetes or dyslipidemia, and alcohol consumption can cause liver disease. These factors frequently co-exist, but their joint effects on liver fibrosis remain uncertain. This study analyzes subjects form the general population with metabolic dysfunction-associated steatotic liver disease (MASLD) enrolled in Spain and U.S. We show that moderate alcohol consumption has a supra-additive effect with metabolic risk factors, exponentially increasing the risk of liver fibrosis. These results suggest that patients with unhealthy metabolic status and MASLD have no safe limits of daily alcohol intake.