Association of environmental cadmium exposure with inflammation and malnutrition in maintenance haemodialysis patients

Background. Chronic inflammation and malnutrition are associated with increased risk of cardiovascular death, and may cause protein-energy wasting in individuals with chronic kidney disease. Raised blood cadmium (Cd) levels were observed in maintenance haemodialysis (HD) patients in previous studies. However, the correlation of Cd exposure with inflammation and malnutrition remains uncertain. This study examined the possible adverse effects of environmental Cd exposure in maintenance HD patients. Methods. A total of 954 maintenance HD patients were enrolled and divided into four equal-sized groups based on blood Cd levels. Geographic, haematological, biochemical and dialysis-related data were obtained. The analysis included values for nutritional and inflammatory markers. Results. Abnormal blood Cd levels (>= 1 mu g/L) were exhibited in 26.8% (256/954) of studied subjects. More subjects in the highest quartile group were malnourished (chisquare = 23.27; P < 0.0001) and had inflammatory changes (chi-square = 13.99; P = 0.0029) than in the lowest quartile group. Stepwise multiple regression analysis revealed a significant inverse correlation between serum albumin and blood Cd levels. Notably, a 10-fold increase in blood Cd levels was associated with a 0.06 g/dL decrease in serum albumin levels (P = 0.0060). Multivariate regression analysis also demonstrated a positive correlation between inflammatory risk (high-sensitivity C-reactive protein >3 mg/L) and blood Cd levels. The risk ratio of inflammation with a 10-fold increase in blood Cd levels was 1.388 (95% CI: 1.025-1.825, P = 0.0336). Conclusions. Environmental Cd exposure is significantly associated with malnutrition, inflammation and even protein-energy wasting in maintenance HD patients. It is important for this population to avoid diets with high Cd concentrations and smoking.