Study On Relationship Between Metals Exposure And IgA Nephropathy In Guangxi Population

Background and Objective:Now,IgAN is a common primary glomerular disease in the world.The high recurrence rate of IgAN patients after kidney transplant surgery suggests that the causative factors of IgAN were of extrarenal origin.It generally acknowledges the effects of environmental,immune,and genetic factors.Although the clinical diagnosis and treatment of IgAN,which produces rapid growth,its causes and mechanisms are not yet clear.Guangxi is known as the“home of non-ferrous metals”and its heavy metal pollution is a wide concern.This study aims to test the levels of metals in plasma and their relationship with the risk of IgAN in the Guangxi population,to explore the relationship between multiple metals and IgAN,and to provide a scientific basis for the development of population-based IgAN prevention and control.Methods:A case-control design approach was used,and the case group was 99 adult patients with IgAN diagnosed by renal tissue biopsy admitted to the nephrology department of a hospital in Nanning,Guangxi,from September 2016 to December 2019.297 healthy volunteers were selected as a control group from the health screening clinic population of the same hospital by 1:3 matching of age（±2 years）and gender in July 2019.The questionnaire information（e.g.,basic demographic information,lifestyle,exposure history,etc.）and blood plasma of this study population were collected.The study measured plasma V,Cr,Mn,Co,Cu,Zn,As,and Pb of all participants by ICP-MS.The influencing factors of IgAN patients were analyzed by one-way and multivariate logistic regression.The relationship of metal and the risk of IgAN was analyzed by the conditional logistics regression model.We used BKMR model to assess the interaction of mixed metal exposure on the risk of IgAN.Results:1.This study included 216 males and accounted for 54.55%and the average of case and control group was 39.03 years and 39.46 years,respectively.2.Multivariate logistic regression analysis showed that the risk of IgAN with a history of smoking was 2.26 times higher than that of people without a history of smoking（95%CI=1.12-4.59,P<0.05）,and that smoking may be an independent risk factor for the development of IgAN.The exercise was an independent protective factor for the risk of developing IgAN compared to the no-exercise population（OR=0.68,95%CI:0.31～0.49,P<0.05）.3.High median plasma concentrations of V,Cr,Mn,Zn,As,and Pb in the case group compared to the control group（V:2.91μg/L vs.2.43μg/L;Cr:2.83μg/L vs.2.26μg/L;Mn:4.57μg/L vs.2.53μg/L;Zn:3266.39μg/L vs.1224.93μg/L;As:1.07μg/L vs.0.68μg/L;Pb:3.48μg/L vs.1.50μg/L,P<0.05）.In contrast,the plasma Co level in the case group was 0.13（0.10-0.18）μg/L,which was lower than 0.17（0.10-0.23）μg/L in the control group,and the difference between the two groups was statistically significant.4.All study subjects were divided into high and low concentration groups according to the mean metal concentration in the control group.The results of the conditional logistic regression analysis,regarding the low concentration group,after adjusting race,BMI,smoking history,passive smoking,history of alcohol,exercise and occupation,the high concentration plasma V（OR=2.92,95%CI=1.53～5.59,P<0.01）、Mn（OR=2.30,95%CI=1.25～4.26,P=0.01）、Zn（OR=3.46,95%CI=1.81～6.62,P<0.01）、As（OR=4.53,95%CI=2.28～9.00,P<0.01）and Pb（OR=5.05,95%CI=2.47～10.30,P<0.01）have positive correlation with the risk of IgAN(P_FDR<0.05).5.The results of BKMR show that an S-shaped association between the plasma mixtures of V,Cr,Mn,Zn,Co,Cu,As,Pb and the risk of IgAN at low concentrations of exposure,with an increasing risk of IgAN with increasing concentrations of the poly-metallic mixture.There was no interaction between two plasma metals regarding the risk of IgAN.Conclusion:1.Smoking may be a risk factor for IgAN and exercise may be a protective factor for IgAN.2.High V,Mn,Zn,As and Pb exposure may significantly associated with increasing IgAN.3.The BKMR model found that the concentrations of metal mixtures V,Cr,Mn,Zn,Co,Cu,As,Pb were associated with the risk of IgAN,suggesting that metal mixtures maybe environmental risk factors for IgAN.