Epidemiological Study Of Autoimmune Thyroiditis And Its Related Diseases

Aim:Although autoimmune thyroiditis?AIT?is highly prevalent,the understanding of AIT is limited.This study aimed to investigate the age and gender-specific distribution of AIT in natural populations in East China,and to evaluate whether there existed a close relationship of AIT with cardiometabolic disorder,non-alcoholic fatty liver disease?NAFLD?and estradiol to total testosterone ratio?E₂/T?among men.Methods:Our data of 10441 adults were from a cross-sectional study,Survey on Prevalence in East China for Metabolic Diseases and Risk Factors in 2014 and 2015?SPECT-China,ChiCTR-ECS-14005052,www.chictr.org.cn?.This study was performed in Shanghai,Zhejiang,Jiangxi,Jiangsu and Anhui Provinces,22 sites in East China.Participants aged more than 18 years old who were Chinese citizens and had lived in their current residence for more than 6 months were invited to this study.AIT was defined according to the positivity of thyroid peroxidase antibody?TPOAb?,thyroglobulin antibody?TgAb?,and the thyroid ultrasonography?US?findings.Results:?1?Overall,the prevalence of positivity for TPOAb and/or TgAb[TPO/TgAb?+?]was11.2%?men:11.2%and women:23.9%?,and the positivity for TPOAb and/or TgAb together with US[TPO/TgAb?+?&US?+?]was 4.7%?men:4.7%and women:13.2%?.Participants with AIT had higher risks of thyroid dysfunctions?thyroid stimulating hormone?TSH?<0.55mIU/L or>4.78mIU/L?.?2?Among the participants with normal TSH levels,AIT was significantly associated with higher BMI,waist circumference?WC?,hemoglobinA1c?HbA1c?and homeostasis model insulin resistance?HOMA-IR?,and increased risks of obesity,central obesity,hyperlipidemia and metabolic syndrome?all P<0.05?in women after full adjustment.For men,AIT was only positively associated with BMI and WC,and increased risk of obesity?all P<0.05?.?3?Among the participants with normal TSH levels,the presence of NAFLD was positively associated with the level of TPOAb in men?P<0.001?and TgAb in women?P=0.001?.Both TPO/TgAb?+?and TPO/TgAb?+?&US?+?was associated with an increased risk of NAFLD[TPO/TgAb?+?:men:odds ratio?OR?1.474,95%CI 1.102,1.970,and women:OR 1.308,95%CI 1.061,1.612;TPO/TgAb?+?&US?+?:men:OR1.796,95%CI 1.143,2.820,and women:OR 1.380,95%CI 1.058,1.801].?4?Among men,the prevalence of TPO/TgAb?+?&US?+?significantly increased with an increasing level of E₂/T?P=0.013?.Binary logistic analysis showed that increased E₂/T ratio levels were associated with an increased risk of AIT[TPO/TgAb?+?:OR 1.345,95%CI 1.116,1.620;TPO/TgAb?+?&US?+?:OR 1.477,95%CI 1.121,1.947].Conclusion:AIT was highly prevalent in East China,and it was much more common in women.Participants with AIT had higher risks of thyroid dysfunctions.Among participants with normal TSH levels,thyroid autoimmunity was positively associated with higher levels of BMI,WC,HbA1c,HOMA-IR,and higher risks of obesity,central obesity,hyperlipidemia,metabolic syndrome and NAFLD,especially in women.In addition,higher E₂/T ratios were significantly associated with AIT among men.This study would provide a basis for future prevention and treatment strategies of AIT and the possible mechanisms remained to be further studied.