Associations Of Plasma Metal Concentrations With The Decline In Kidney Function

Objective:As widespread pollutants in the environment,metals have been reported to be associated with kidney dysfunction in many existing epidemiological studies.However,most of the studies are cross-sectional designed and mainly focus on several toxic metals including arsenic,lead and cadmium.Therefore,we conducted this prospective study within the Dongfeng-Tongji cohort to evaluate the associations of plasma multiple metals with the decline in kidney function and incident chronic kidney disease among Chinese elderly.Methods:A total of 2264 participants free of chronic diseases at baseline were included in analysis.Baseline plasma concentrations of 23 metals were measured using Inductively coupled plasma mass spectrometry(ICP-MS).Estimated glomerular filtration rate(eGFR)was calculated using the Chronic Kidney Disease Epidemiology Collaboration(CKD-EPI)equation.Annual eGFR decline,rapid kidney function decline and chronic kidney disease were used to indicate the decline in kidney function.Linear regression models and logistic regression models were used to investigate the associations of metals with the decline in kidney function.Furthermore,principal component analyses(PCA)were applied to explore the potential metal principal components(PCs)that associate with the decline in kidney function.Results:Plasma concentrations of aluminum,arsenic,barium,manganese,rubidium,strontium,thallium,vanadium and zinc were observed to be significantly associated with annual eGFR decline after multivariate adjustment and Bonferroni correction.Comparing the 75th to the 25th percentile of plasma metals,the decline in annual eGFR increase 0.43(95%CI:0.27-0.59),1.07(95%CI:0.86-1.27),0.51(95%CI:0.32-0.70),0.29(95%CI:0.12-0.46),0.99(95%CI:0.80-1.17),0.32(95%CI:0.13-0.51),0.23(95%CI:0.06-0.40),0.69(95%CI:0.49-0.89)and 0.76(95%CI:0.60-0.92)ml/min/1.73 m2,respectively.Four metals were significantly associated with increased risk of rapid renal function decline and incident CKD.For plasma arsenic,rubidium,vanadium and zinc,when comparing the 75th to the 25th percentile of plasma metals,the OR for rapid renal function decline were 1.80(95%CI:1.48-2.20),2.58(95%CI:2.12-3.15),1.38(95%CI:1.15-1.64)and 1.55(95%CI:1.35-1.77),whereas the OR for incident CKD were 1.77(95%CI:1.47-2.14),2.02(95%CI:1.69-2.42),1.36(95%CI:1.14-1.62)and 1.42(95%CI:1.24-1.63),respectively.PCA were conducted and five PCs with eigen values>1 were extracted.PC1(aluminum,arsenic,barium,lead,vanadium and zinc)and PC5(rubidium and selenium)were significantly associated with the annual eGFR decline.Conclusions:Arsenic,rubidium,vanadium and zinc significantly increased the risk of kidney function decline.Aluminum,barium,manganese,strontium and thallium were significantly associated with annual eGFR decline.Further studies are required to confirm our findings and explore the potential mechanisms.