| Objective:To investigate the correlation between iodine nutritional status and the risk of developing papillary thyroid cancer（PTC）by studying the differences in the concentrations of urinary iodine（UIC）and serum iodine（SIC）in PTC,nodular goiter（NG）and healthy controls.Methods:This study is a retrospective analysis.According to the inclusion criteria,a total of 68adults who had undergone thyroid surgery were selected from the Department of Thyroid Surgery of the Second Hospital of Jilin University between November 2021 and November2022 and were divided into 21 cases in the NG group and 47 cases in the PTC group according to the pathology results.36 cases were selected from the same period of healthy persons.Peripheral venous blood was drawn after a night of fasting,and serum iodine concentrations（SIC）were detected by means of As3+-Ce4+catalytic spectrophotometry.Urinary iodine concentrations（UIC）were measured by the chemical method by the Nuclear Medicine Department of the same hospital.Two software packages,IBM SPSS 26.0 and Microsoft Excel,were used for data processing and statistical analyses.To compare different iodine nutritional levels between patients with nodular goiter（NG）or papillary thyroid cancer（PTC）and the controls.Multiple logistic regression analysis was applied to evaluate the risk of PTC.Spearman and partial correlation analysis were used to analyze the correlation.The receiver operating characteristic（ROC）curves for SIC and UIC were constructed and the area under the ROC（AUC）curve was calculated.A P value<0.05 was considered statistically significant.Results:1.Patients in the PTC group had lower levels of SIC than those in the NG group,and the difference was statistically significant（P<0.05）;patients in the PTC group had lower levels of UIC than those in the control group,and the difference was statistically significant（P<0.05）.2.The correlation analysis of SIC with the eight indicators of thyroid function in all study subjects showed that SIC was positively correlated with FT4and TT4,showing moderate correlation strength.there was no significant correlation between SIC and TT3,FT3,TSH,TPOAb,Tg Ab and Tg.3.We performed logistic regression analyses for the risk of thyroid cancer in patients with thyroid nodules（NG）.SIC（OR=0.913,95%CI:0.868-0.999,P=0.046）were independent predictors for thyroid cancer.Within the normal range,patients with relatively low iodine intake had a greater risk of having thyroid cancer.4.Using the postoperative pathological results as the gold standard,the ROC curves of SIC and UIC were constructed separately.In the diagnosis of PTC,the AUC of SIC was 0.7112（P=0.0056,95%CI:0.5780-0.8445）,with a better auxiliary diagnostic efficacy,when the sensitivity was 0.745 and the specificity was 0.667,when the Jorden index was maximum,corresponding to a cut-off the AUC of UIC was 0.5187（P=0.806,95%CI 0.3664-0.6711）,with poor diagnostic efficacy.Conclusions:1.SIC is independently associated with the development of PTC.Within the normal range,lower serum iodine leads to an increased risk of PTC development.Increasing serum iodine concentration may act as a protective factor against the malignant transformation of thyroid follicular cells.2.SIC was positively correlated with TT4 and FT4,suggesting that changes in serum iodine concentration could affect thyroid function.3.SIC has good diagnostic efficacy as a serologic index.SIC can be used in conjunction with ultrasound and other means to determine PTC,and it can play an auxiliary role in guiding dietary iodine intake in specific populations,while the diagnostic efficacy of PTC by UIC is poor. |
