A Cross-sectional Study On The Hypothyroidism Induced By Excessive Iodine

Objective 1.To evaluate the status of residents' iodine nutrition in Haixing County,Cangzhou City of Hebei Province.2.To investigate the prevalence of clinical and subclinical hypothyroidism and effects on thyroid autoantibodies induced by excessive iodine intake.3.To explore the relations among thyroid autoantibodies,hypothyroidism and TSH so as to provide reference data for pathogenesis induced by excessive iodine intake and early detection of thyroid dysfunction.Methods 1.Zhaogao and Fuzhuangzi village were chose as the area of excessive iodine and Xiaoshan village as that of adequate iodine in base of the monitoring data.2.The objects of study that were from twenty to fifty,no receiving the operation and treatment of thyroid,living five years in local at least were chose.3.The objects of study were inquired by the method of questionnaire survey,including general conditions,the histories of living in local,thyroid diseases and family.4.Collect the sample of fasting urine,venous blood and water and then determine.Results 1.The median of adequate and excessive iodine areas were 185.20?g/L(146.46?237.93?g/L)and 1152.01?g/L(753.03?1539.01?g/L).2.The median of sTSH were 2.71?IU/ml and 2.41?IU/ml in the total and normal population of the excessive iodine area,which were higher than those of adequate iodine area(P<0.05).3.In the excessive iodine area,the total and women prevalence of thyroid disease were 20.6%and 25.5%,which were 2 and 2.5 times than those of adequate iodine ares(P<0.05).4.The first position of the thyroid disease structure was subclinical hypothyroidism both of adequate and excessive iodine areas.5.The prevalence of clinical and subclinical hypothyroidism in the excessive iodine area were 3.6%and 13.6%,which were increased than those of adequate iodine area(P<0.05).And in the excessive iodine area,the prevalence of subclinical hypothyroidism of women was higher than men of adequate iodine area(P<0.05).6.No differences were found in the positive rates of TGAb and TPOAb between adequate and excessive iodine areas(P>0.05).The positive rates of TGAb and TPOAb had revealed gender differences.7.The positive rates of TGAb,TPOAb and both were 36.4%,40.9%and 31.8%in the population of hypothyroidism and TPOAb was 26.8%in the population of subclinical hypothyroidism,which were increased than those in the normal population(P<0.05).The prevalence of clinical and subclinical hypothyroidism in the levels above 60%were higher than those below 60%(P<0.05).8.The positive rates of TGAb and TPOAb in the population of sTSH>5.0?IU/ml were higher than those of sTSH 0.3-5.0?IU/ml in the adequate iodine area(P<0.05).And the positive rates of TGAb and TPOAb of adequate iodine area were increased than those of excessive iodine area when sTSH>5.0?IU/ml(P<0.05).9.In the population of TGAb and TPOAb positive,the median of sTSH were higher than those of TGAb and TPOAb negative in the adequate iodine area(P<0.05).In the population of TGAb and TPOAb negative,the sTSH level of excessive iodine area was higher than that of adequate iodine area(P<0.05).Conclusions 1.The iodine deficiency was eliminated in the adequate and excessive iodine areas.The residents living in the excessive iodine area have iodine excess intake.2.Increased sTSH and decreased FT3 levels were found in the population of iodine excess intake,especially in the population of normal thyroid function.3.The prevalence of thyroid disease,clinical and subclinical hypothyroidism was increased resulting from higher prevalence of women induced by excessive iodine.There were gender differences in the positive rates of TAA.4.Increased positive rates of TAA were found in the population of clinical and subclinical hypothyroidism.5.In the population of sTSH>5.0?IU/ml had higher positive rates of TAA,and TAA positive population followed higher sTSH level.So thyroid autoimmunity was the main reason of clinical and subclinical hypothyroidism.6.Increased sTSH was found in the excessive iodine area when TAA negative.Therefore,people even had normal thyroid autoimmunity had higher danger risk of thyroid dysfunction in the excessive iodine area than those of adequate ares.7.The women and people who had positive TAA should monitor thyroid function.We suggested that took some measures to prevent and control the thyroid diseases induced by iodine excess intake.