Meta Analysis Of The Relationship Between Alopecia Areata And Thyroid Autoimmunity

Objective:To investigate the relationship between the etiology of alopecia areata and thyroid autoimmunity,and to provide a reference for the clinical treatment of alopecia areata.Methods:Using the strategy of combining subject words with free words,the relevant literatures on the relationship between alopecia areata and thyroid are searched in Wanfang,CBM,CNKI databanks and Pubmed,Embase,Cochrane.The search date is limited to the establishment of the library until May 31,2018.Establish literature inclusion criteria:1 The literature is related to the relationship between alopecia areata and thyroid;2 The study subjects excluded other systemic diseases and autoimmune diseases;3Research must include laboratory tests to measure thyroid autoantibodies and/or thyroid function;4 Research must have been published in English or Chinese;5 In the study,thyroid disease can be included in subclinical or clinical status.Establish literature exclusion criteria:1 Study with less than 20 samples;2 Literature that only has quantitative data and cannot calculate the positive rate;3 The literature was repeatedly published;4Incomplete literature;5 Literature on low quality evaluation of methodology;6 Reviews,lectures and other non-research literature;7 Grey literature not published in full,conference papers and non-Chinese and English literature published in full text;8 No case-control study.The research data were extracted and collated independently by two researchers and the methodological quality evaluation of the included studies was carried out.Meta analysis,meta regression analysis,subgroup analysis,sensitivity analysis and publication bias evaluation were performed with Stata 14.0 software.Results:A total of 16 articles were selected,of which 5 were published in Chinese and 11 were published in English.The selected literature included a total of 16 case-control studies.There were 6796 people in the alopecia areata group and 790,517 in the healthy control group.The positive rate of thyroid autoantibodies in the alopecia areata group was significantly higher than that in the healthy control group,and the difference was statistically significant(OR=5.377,95%CI=4.196-6.891,Z=13.29,P=0.000).There is a slight heterogeneity between the studies(X2=14.22,df=11(P=0.221),I2=22.7%).The result is stable and reliable.Currently,routinely detected thyroid autoantibodies include anti-thyroid peroxidase antibody(TPOAb),anti-thyroglobulin antibody(TGAb)andanti-thyroid microsome antibody(TMAb).The positive rate of these antibodies in alopecia areata patients is higher than that in healthy control group.The positive rate of autoimmune thyroid diseases(AITD)in the alopecia areata group was significantly higher than that in the healthy control group,and the difference was statistically significant(OR=3.485,95%CI=1.991-6.099,Z=4.37,P=0.000).There is a slight heterogeneity between the studies(X2=2.22,df=2(P=0.330),I2=9.7%).The result is stable and reliable.The positive rate of thyroid dysfunction in the alopecia areata group was significantly higher than that in the healthy control group,and the difference was statistically significant(OR=4.372,95%CI=1.310-14.588,Z=2.40,P=0.016).There is a high heterogeneity between the studies(X2=16.34,df=2(P=0.000),I2=87.8%).The result is not stable and reliable.Conclusion:1.The positive rate of thyroid autoantibodies and AITD in the alopecia areata group is higher than that in the healthy control group,which has certain guiding significance for clinical diagnosis and treatment.2.Currently,routinely detected thyroid autoantibodies include TPOAb,TGAb and TMAb.The positive rate of these antibodies in alopecia areata patients is higher than that in healthy control group,and it has reference value for targeted laboratory tests in clinical work.3.The positive rate of thyroid dysfunction in the alopecia areata group was higher than that in the healthy control group,but the results were not reliable enough.4.This study has some limitations on the study of the relationship between alopecia areata and thyroid autoimmunity.The conclusions can only be used as a lower level of evidence-based medical evidence to guide the clinical.More prospective cohort studies with high strength are needed to further explore the etiology and pathogenesis of alopecia areata.