Dietary sodium density as a potential nutritional marker of HSI-defined hepatic steatosis in Korean adults: a nationwide cross-sectional study with a dose–response analysis

BACKGROUND: The association between energy-adjusted dietary sodium density and non-invasively assessed hepatic steatosis remains poorly defined in population-based studies. AIM: We investigated the association and dose-response relationship between dietary sodium density and HSI-defined hepatic steatosis in Korean adults. METHODS: We analyzed 14,445 adults (aged ≥20 years) from the 2021-2023 KNHANES. Sodium intake from a 24-h recall was calculated as sodium density (mg/1,000 kcal). HSI ≥36 defined hepatic steatosis; descriptive analyses compared HSI <36 versus ≥36, whereas regression analyses used HSI <30 as the reference, with HSI 30.0-35.9 treated separately. RESULTS: Compared with HSI <30, each 100 mg/1,000 kcal increase in sodium density was associated with higher odds of HSI-defined hepatic steatosis across all models: Unadjusted OR 1.058 (95% CI 1.032-1.085; P<0.001), Age/Sex-adjusted OR 1.051 (95% CI 1.024-1.079; P<0.001), Lifestyle-adjusted OR 1.048 (95% CI 1.020-1.077; P=0.001), and Fully adjusted OR 1.054 (95% CI 1.020-1.089; P=0.002). Participants in the highest sodium density quartile (Q4) exhibited 36.2% higher odds of HSI-defined hepatic steatosis than those in the lowest quartile (Q1) (adjusted OR 1.362; 95% CI 1.144-1.621; P=0.0004; P for trend = 0.001). The association remained robust after adjusting for potassium density (OR 1.042; 95% CI 1.012-1.072; P=0.005). RCS analysis showed an approximately linear increase in odds across the observed range, without evidence of non-linearity (P=0.738). CONCLUSIONS: Elevated sodium density was associated with higher odds of HSI-defined hepatic steatosis and may serve as a nutritional marker of metabolic liver health.