The association between cadmium exposure and axonal injury biomarker, serum neurofilament light chain levels in US adults

Abstract

Background and Aims: Cadmium exposure has been shown a toxic effect on the nervous system, but little is known regarding the link between cadmium exposure and axonal injury. Therefore, we aim to investigate whether there is a relationship between blood cadmium and serum neurofilament light chain (NfL) levels in the general population. Methods and Results: In the National Health and Nutrition Examination Survey 2013–2014, 1,040 participants with a median (IQR) age of 47 (35–60) years are enrolled. Serum NfL levels are measured using a highly sensitive immunoassay. Whole blood cadmium concentrations are detected using inductively coupled plasma mass spectrometry. Linear regression and restricted cubic spline models are used to analyze the strength and shape of the relationship between blood cadmium and serum NfL levels. In full adjusted model, blood cadmium levels are positively associated with serum NfL levels (Q4 vs Q1, β = 3.35, 95%CI: 0.41, 6.30, p for trend = 0.014). A potential linear positive dose-effect relationship is found between blood cadmium and serum NfL levels (p for non-linearity = 0.15), and the potential threshold dose of blood cadmium is 0.7 µg/L. The stratified analysis shows a significant positive relationship between blood cadmium and serum NfL levels is limited to middle-aged and older adults. Conclusion: The present study suggests a positive association between blood cadmium and serum NfL levels in the general US population. This study is expected to provide new ideas for the primary prevention and mechanism exploration of neurodegenerative diseases.