A Case-control Study Of Association Between Exposure To Multiple Trace Elements And Nodular Goiter

Objective China’s industrialization has been accompanied by huge energy consumption and serious pollution,including heavy metals,waste gas,biochemical and other harmful substances,and people are more likely to be exposed to various inorganic elements.When the concentration of trace elements is too high or too low,it can cause damage to several organs,including the thyroid gland.The objective of this study is to investigate the concentration distribution of 15 trace elements in the urine of Nodular Goiter patients and controls,and to investigate their association with the risk of nodular goiter.MethodsA total of 374 newly diagnosed NG cases were collected from the First Affiliated Hospital of Anhui Medical University,the Second Affiliated Hospital of Anhui Medical University and Anhui Cancer Hospital from August 2017 to October 2020.A case-control study was conducted from the three hospitals with 1:1 individual matching according to age(±5years),sex and residence.There were 374 newly admitted patients without endocrine disease.A one-to-one questionnaire survey was conducted on the 748 subjects to obtain general demographic information,behavioral habits,radiation exposure history and female reproductive history,as well as relevant clinical information of all subjects,including height,weight,systolic blood pressure,diastolic blood pressure and previous disease history,etc.Midmorning urine and fasting blood of the second day after admission were collected.The graphite furnace atomic absorption spectrometer was used to detect the content of cadmium in the urine of the subjects.The inductively coupled plasma emission spectrometer was used to detect the content of 13 other trace elements in the urine.The urine creatinine concentration was determined by ultraviolet spectrophotometer to correct the concentration of metal elements.And the urine iodine level was detected by arsenic and cerium photometry.Conditional Logistic regression was used to analyze single trace elements and multiple trace elements.In addition,the regression model of Least Absolute Selection and Selection Operator(LASSO)can be used to select representative elements into the multi-element model for dimensional reduction.Bayesian Kernel Machine Regression(BKMR)was used to further explore the influence of elements and the interactions between elements.ResultsA total of 374 NG cases were collected in this study,with an average age of 52.27 ± 11.42 years old,and 374 control cases with an average age of 53.19 ± 11.63 years old.There were 91 males and 283 females in both groups.In the single-element model,high concentrations of iodine and manganese were positively associated with an increased risk of NG after adjusting for various potential mixing factors.The overall concentrations of lithium and strontium were negatively correlated with the increased risk of NG.The third quantile concentration of cobalt was negatively correlated with the increased risk of NG,while the second and third quantile concentration of selenium was positively correlated with the increased risk of NG.The second and third quantiles of barium were negatively correlated with the increased risk of NG.The highest score of lead was positively associated with an increased risk of NG.In the multi-element model,the highest digit concentration of iodine was still positively associated with an increased risk of NG after adjusting for various potential confounders.The overall concentration of lithium was still negatively associated with the increased risk of NG.The highest digit concentration of lead was still positively associated with an increased risk of NG.Strontium has a significant relationship with NG.In the BKMR model,consistent with the results of the multi-element model,the effects of iodine and lead increase monotonically with the increase of concentration,and lithium and strontium have certain protective effects on NG.At the same time,it is found that lithium interacts with lead and strontium.Low exposure of lithium may cooperate with the protective effect of strontium on NG and antagonize the harmful effect of lead on NG.In the female subgroup analysis,the third and second fractions of barium and selenium,the third quantile of cobalt and lithium were negatively associated with an increased risk of NG in women,while iodine increased the risk of NG in women without adjustment for other trace elements.Manganese is associated with the onset of NG.After adjustment for other trace elements,only iodine,lithium and manganese were associated with NG occurrence.ConclusionsIn this study,iodine and lead can significantly increase the risk of NG,while lithium and strontium have certain protective effects on NG.At the same time,it is found that lithium interacts with lead and strontium.Low exposure of lithium may cooperate with the protective effect of strontium on NG and antagonize the harmful effect of lead on NG.