Background: With the rising incidence of chronic diseases, and the increase of aging population has led to multimorbidity a serious public health problem. The aim of this study was to explore the association between metal exposures and Charlson comorbidity index (CCI), which will provide valuable information for improving quality of life and reducing mortality.
Methods: The study sample consists of three continuous cycles (2011-2016) of the National Health and Nutrition Examination Survey (NHANES), and 4901 eligible subjects were included in the study. Zero-inflated negative binomial (ZINB) model was utilized to investigate the effects in metal exposures on CCI, which includes spot urine (arsenic, mercury, and cadmium), whole blood (manganese, selenium, and lead), and serum (copper and zinc).
Results: In count part (CCI ≥ 0), holding other variables constant, the expected change in CCI for a one-unit increase in blood selenium is 0.997 (RR = 0.997, p = 0.017). In logit part (CCI = 0), the log odds of having CCI equals zero would increase by 0.659, 1.073, and 0.963 for every additional urinary cadmium (OR = 0.659, p = 0.007), blood lead (OR = 1.073, p = 0.023), blood manganese (OR = 0.963, p = 0.025), respectively.
Conclusions: Our findings indicated that cadmium and manganese were likely to increase mortality. Inversely, selenium and lead might be positive on people's health. The findings may be extremely essential for preventing diseases and improving life quality.
Keywords: Charlson comorbidity index (CCI); Metal exposures; Multimorbidity; Zero-inflated negative binomial (ZINB).