Associations among global long interspersed nuclear element-1 DNA methylation, metal exposure, and chronic kidney disease

Long interspersed nuclear element-1 (LINE-1) methylation serves as an indicator of global DNA methylation. This study explored the correlation between LINE-1 methylation and chronic kidney disease (CKD). We also evaluated whether LINE-1 methylation could modify the association between CKD and metal exposure. A total of 213 patients with clinically defined CKD, without hemodialysis and 416 age and sex matched controls were recruited. Levels of LINE-1 methylation, total urinary arsenic, blood lead, blood cadmium, and plasma selenium were assessed. The results reveal a positive association between LINE-1 methylation and CKD, with an odds ratio (OR) of 5.30 (95% confidence interval: 2.81 to 9.99). Total urinary arsenic and blood cadmium concentrations were positively related with LINE-1 methylation. This study was the first to observe that low plasma selenium, high blood cadmium, and high blood lead levels significantly and additively interact with increased LINE-1 methylation to increase the OR of CKD. Additionally, high LINE-1 methylation interacted multiplicatively with low plasma selenium to increase the OR of CKD (p < 0.001). This study highlighted the significant association between LINE-1 hypermethylation and CKD. Furthermore, the results demonstrate that LINE-1 methylation can interact with high blood cadmium or low plasma selenium to affect CKD risk.