Serum Vitamin D Affects the Association Between Cadmium and abdominal aorta calcification: A Cross- Sectional Study

Abstract

Background Cadmium is a toxic heavy metal that can accumulate in the body over time and the exposure to this element has been linked to abdominal aorta calcification. Vitamin D deficiency has also been reported to be associated with vascular calcification risk. It has been proposed that cadmium's toxic effect is exerted via impaired activation of vitamin D. Therefore, we designed this cross-sectional study to assess the effect modification of vitamin D on the association between Cadmium and risk of AAC. Method The cross-sectional observational study used data from the 2013-2014 National Health and Nutrition Examination Survey. By having stratified participants based on Serum Vitamin D category (low Serum Vitamin D <70.65 nmol/L; high Serum Vitamin D: ≥70.65 nmol/L), we further evaluated the difference (interaction test) between the relationship of Cadmium with the risk of AAC among low Serum Vitamin D participants and high Serum Vitamin D participants using weighted multivariable logistic regression. Results The sample analyzed in this study consisted of 846 participants aged ≥40 years, with 422 participants having serum vitamin D levels below 70.65 nmol/L and 424 participants having levels above 70.65 nmol/L. Our findings show that as total cadmium levels increased, the incidence of AAC also increased significantly in the high serum vitamin D group (p=0.002), indicating a significant interaction between serum vitamin D, cadmium, and AAC occurrence (p-value for probability ratio test=0.005). However, in the low serum vitamin D group, there was no statistically significant difference (p=0.197). Sensitivity analysis indicated that our results remained stable after excluding imputed data. Furthermore, our results show that as total cadmium levels increased, the incidence of severe AAC was significantly higher in the high serum vitamin D group (OR=3.52, 95% CI: 1.17-10.55, p=0.025). Conclusion The results of our study indicated that Serum Vitamin D might affect the association of Cadmium with the risk of AAC. More randomized controlled trials are required to further support this finding.