Income Persistence and the Risk of Hepatocellular Carcinoma in Individuals with Type 2 Diabetes

BACKGROUND:This study aimed to examine the cumulative effect of income on hepatocellular carcinoma (HCC) risk in individuals with type 2 diabetes (T2D). METHODS:A nationwide cohort of 1,516,897 adults with T2D and no history of cancer (2015-2016 baseline) from the Korean National Health Insurance Service was analyzed. Annual income was categorized into quartiles based on health insurance premiums, designating the highest quartile and lowest quartile as high- and low-income groups, respectively. Cumulative income status was assessed over 5 years, including the 4 years preceding and the baseline year. Incident HCC was identified via International Classification of Diseases, Tenth Revision (ICD-10) code. RESULTS:The hazard ratio (HR) for 5-year consistent high-income status was 0.68 [95% confidence interval (CI), 0.65-0.72] compared with those never classified as the high-income group, whereas the HR for 5-year consistent low-income status was 1.34 (95% CI, 1.26-1.43) compared with those never classified as the low-income group. The HCC risk showed a significant duration-dependent trend in relation to cumulative exposure to low or high income, respectively (Ptrend < 0.0001). The association was stronger in those without chronic liver disease or major cancer risk factors and remained robust after adjusting for diabetes-related factors. CONCLUSIONS:Prolonged low- or high-income status was independently associated with HCC risk among individuals with T2D, with a clear duration-dependent pattern. IMPACT:These findings emphasize how income stability independently affects the incidence risk of HCC in individuals with T2D.