Relationship between cadmium exposure, triglyceride-glucose index and carotid artery atherosclerosis

Introduction: Cadmium exposure is suggested to be associated with cardiovascular and metabolic diseases. We investigated the association between cadmium and carotid artery atherosclerosis and the mediating effect of serum triglyceride and glucose level represented by triglyceride-glucose index (TyG index). Methods: Among Cardiovascular and Metabolic disease Etiology Research Center (CMERC) Cohort participants, participants who received serum heavy metal screening tests were selected (N=200). Patients with more than 3 standard deviation level of serum cadmium were excluded (N=1). TyG index was calculated as formula: ln [{fasting blood glucose (mg/dL) × triglyceride (mg/dL)}/2]. Carotid artery ultrasonography was conducted to test carotid artery atherosclerosis. Carotid artery plaque was considered present if the thickness is greater by 50% or more than the surrounding intima-media thickness or if its size was 1.5mm or more. We used linear regression to test the association between serum cadmium level and TyG index, and Poisson regression to test the association between serum cadmium level, TyG index and number of plaques. Mediation analyses was conducted to detect the mediating effect of TyG index. Results: Serum cadmium level was associated with TyG index (β=0.155, p-value=0.042). Both serum cadmium level(β=0.753, p-value=0.039) and TyG index(β=1.049, p=0.010) were associated with number of carotid artery plaques. Mediation analyses showed that TyG index significantly mediated the association between serum cadmium level and carotid artery plaque (direct effect: β=0.733, p-value=0.042; indirect effect: β=0.165, p-value=0.048). Conclusion: Cadmium exposure increases the risk of carotid artery atherosclerosis. The assocaition is mediated by disturbance in serum triglyceride and glucose level.