Associations of serum cadmium ions levels with all-cause mortality in adults with NAFLD in the United States: An analysis of the NHANES 2017–2018

Cumulative evidence links cadmium exposure to various systemic disorders, yet its prognostic impact on non-alcoholic fatty liver disease (NAFLD) remains poorly understood. Using data from the National Health and Nutrition Examination Survey (NHANES) 2017–2018, this study included 1787 U.S. adults with NAFLD defined by vibration-controlled transient elastography (controlled attenuation parameter ≥248 dB/m) after excluding significant alcohol intake and viral hepatitis. Cox proportional hazards models were applied to assess the association between cadmium exposure and all-cause mortality, with adjustment for dietary factors, environmental co-exposures, and other potential confounders. During a median follow-up of 23.6 months, higher cadmium exposure was significantly associated with increased all-cause mortality. Participants in the highest cadmium quartile had a hazard ratio (HR) of 3.62 (95 % CI: 1.08–12.12) compared to the lowest quartile, with a significant dose–response trend (p for trend=0.008) and mortality rates increased from 4.2 to 18.0 per 1000 person-years across cadmium quartiles. Notably, smoking history synergistically amplified the cadmium-related mortality risk, with former smokers exhibiting the highest risk (HR=2.57, 95 % CI: 1.15–5.75). These findings highlight serum cadmium as an independent predictor of mortality in NAFLD and underscore the importance of integrating environmental exposure assessment and targeted smoking cessation strategies into clinical management for this population. • Elevated serum cadmium is associated with increased mortality NAFLD adults. • Highest cadmium quartile had a 3.6-fold greater mortality risk than the lowest. • The association between serum cadmium and mortality was strongest in former smokers. • Cadmium exposure assessment may aid NAFLD risk stratification. • Reducing cadmium exposure and smoking may lower NAFLD-related mortality risk.