Independent and Combined Associations of Blood Manganese, Cadmium and Lead Exposures with the Systemic Immune-Inflammation Index in Adults

Manganese (Mn), cadmium (Cd) and lead (Pb) have toxic effects on the immune system. However, their independent combined immune-inflammation responses are unclear. In recent years, systemic index (SII) has been developed as an integrated novel inflammatory indicator. A retrospective cross-sectional study of 2174 adults ≥20 years old from National Health Nutrition Examination Survey (NHANES) 2015–2016 was conducted. Generalized linear models were used to evaluate associations SII with blood Mn, Cd Pb levels. As continuous variables, both Mn showed dose-dependent relationships before after adjusting for all potential confounding factors. Metal concentrations then converted into categorical variables. Compared in lowest or tertile, those highest tertile had higher risks elevated SII. Furthermore, co-exposure also a positive relationship single effect exposure joint other metal exposures not observed. This provides important epidemiological evidence Cd, Pb.