A Cross-sectional Study Of Relationship Between Serum Selenium Level And Thyroid Function

Objective:To understand serum selenium status and the prevalence of abnormal thyroid function of populations in shanxi area,at the same time,investigate the relationship between serum selenium level and thyroid function,in order to provide more theory basis in prevention and treatment of thyroid diseases.Methods:This study was a cross-sectional study,we selected 1470 residents of shanxi area using astratified cluster sampling technique,everyone signed the informed consent,and collected fasting blood samples.All participants measured thyroperoxidase autoantibody(TPOAb),thyroglobulin autoantibody(TgAb)and thyroid stimulating hormone(TSH),if TSH was reduced,the free thyroxine(FT4)and free triiodothyronine(FT3)were also measured in the same sample,if TSH was raised,then only FT4 was measured.To compare and analyze the relationship between serum selenium levels and various indicators,the incidence of abnormal thyroid function on different selenium concentrations,and the difference of selenium concentration between normal person and different types abnormal thyroid function person.SPSS20.0 was used to analyze the data,normal distribution is compared between multiple sets of data using analysis of variance,non-normal distribution data using nonparametric statistical analysis,correlation analysis uses spearman rank correlation,rate compared with c 2 test,the difference was significant when p<0.05.Results:1.The median serum selenium level of the subjects was 79.38(58.85-128.05)?g/L;2.The prevalences of overt hypothyroidism,subclinical hypothyroidism,overt hyperthyroidism,subclinical hyperthyroidism,TPOAb positive and TGAb positive were1.77%,14.08%,0.68%,0.48%,10.34%,15.65% respectively.3.Serum selenium level for men was 81.78?g/L,76.22?g/L for women,the difference was not significant(p=0.078).With the increasing age,serum selenium showed a reducing trend.4.A negative association between serum selenium concentration and age(r=-0.083,p=0.001)and TSH(r=-0.057,p=0.030)were found;if TPOAb was positive,serum selenium concentration and TPOAb titer present negative association(r=-0.257,p=0.002).5.The serum selenium status of thyroid dysfunction were lower than people who had normal thyroid function besides hyperthyroidism.The serum selenium of group in hypothyroidism and TPOAb >200IU/ml were significantly reduced,the p lvalue were0.008,0.007.6.With the increase of serum selenium,the prevalence of hypothyroidism,TPOAb positive and TGAb positive showed a reducing trend.When the serum selenium was<60?g/L and ?100?g/L,the prevalence of hypothyroidism and TPOAb>200IU/ml was significantly difference,the p lvalue were 0.008,0.007.Conclusion:1.Selenium status was on the edge of adequate level in shanxi area;2.Selenium levels in individuals were unrelated to sex,there is a negative correlation with age,and the serum selenium of eldly was significantly decreased;3.Low-selenium level may be a unfavorable factors in elevate TSH,and play a role in the occurrence and development of hypothyroidism;4.Selenium levels associated with thyroid antibody titer,especially with a high level of TPOAb.Low selenium level may induce or aggravate abnormal immune in thyroid,the high selenium may have some protective effects on the thyroid tissues.