Metabolic dysfunction-associated steatotic liver disease and risk of esophageal cancer in patients with diabetes mellitus: a nationwide cohort study.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is closely associated with type 2 diabetes and a developing several cancers including esophageal cancer (EC). However, the association between MASLD and EC in diabetic patients has not been investigated. Therefore, we aimed to investigate the relation between MASLD and developing EC in diabetic patients. This was a population-based retrospective cohort study of data from the Korean National Health Insurance Service (NHIS). A total of 1,904,468 subjects diagnosed with diabetes who underwent NHIS-provided health checkups from 2009 to 2012 were included. We constructed a Cox proportional hazard model for the association of fatty liver index (FLI) and the risk of EC stratified by potential confounders. Over a mean follow-up duration of 6.9 years, the incidence of EC was higher in the high (≥60) FLI group compared to the low (<30) FLI group (14.4 vs. 13.7 event per 100,000 person-years). The risk of EC correlated with the degree of FLI, particularly in older (P = 0.002), female (P = 0.033), non-smoking (P = 0.002), and non-drinking patients (P = 0.025). Among obese patients, the risk of EC was not associated with FLI; however, the risk of EC was higher in the high FLI group in non-obese patients. Lean MASLD patients had the highest risk of EC (adjusted hazard ratio 1.78; 95% confidence interval, 1.5-2.13). MASLD was associated with an increased risk of EC in diabetic patients, and lean MASLD has the highest risk. Further studies are required to determine the causal relationship between MASLD and EC.