title: Sex differential association of dermatomyositis with Sjögren syndrome.
abstract: BACKGROUND
  Although dermatomyositis and Sjögren syndrome share serologic autoantibodies and genetic polymorphisms, population data about the incidence of Sjögren syndrome in patients with dermatomyositis is unavailable. We performed a nationwide cohort study to explore the potential relation between dermatomyositis and Sjögren syndrome and, if an association exists, to elucidate whether it varies by sex.
  
  
  METHODS
  We identified all patients with newly diagnosed dermatomyositis from the Registry of Catastrophic Illness Database in Taiwan between Jan. 1, 1998, and Dec. 31, 2011. Each patient was matched to, at most, 5 control patients from the National Health Insurance Research Database by age, sex and entry date. Cox regression was used to calculate the hazard ratio (HR) and 95% confidence interval (CI) of Sjögren syndrome after adjusting for age, sex, rheumatoid arthritis, systemic lupus erythematosus and systemic sclerosis.
  
  
  RESULTS
  A total of 1602 patients with dermatomyositis and 7981 control patients were enrolled in the study. There was a positive association of having Sjögren syndrome among patients with dermatomyositis after adjusting for age, sex, rheumatoid arthritis, systemic lupus erythematosus and systemic sclerosis (HR 2.67, 95% CI 2.01-3.54). The association was more pronounced in the male cohort (HR 2.69, 95% CI 1.19-6.09).
  
  
  CONCLUSIONS
  We found a sex differential association of Sjögren syndrome among patients with dermatomyositis independent of age and concomitant autoimmune disease. Further studies are required to determine the clinical importance of this association for both outcomes and therapeutic options.
authors.affiliation: Department of Internal Medicine (Tseng), Kaohsiung Municipal Ta-Tung Hospital; Department of Kinesiology (Chang), Health and Leisure Studies, National University of Kaohsiung; Division of Rheumatology (Tsai, Ou, Wu, Sung, Yen), Department of Internal Medicine, Kaohsiung Medical University Hospital; Graduate Institute of Medicine (Sung, Yen), College of Medicine, Kaohsiung Medical University; Division of Endocrinology and Metabolism, Department of Internal Medicine (Hsieh), Changhua Christian Hospital, Changhua, Taiwan; Graduate Institute of Integrated Medicine (Hsieh), China Medical University, Taichung, Taiwan.
authors.forename: Chia-Chun
authors.initials: CC
authors.lastname: Tseng
authors.affiliation: Department of Internal Medicine (Tseng), Kaohsiung Municipal Ta-Tung Hospital; Department of Kinesiology (Chang), Health and Leisure Studies, National University of Kaohsiung; Division of Rheumatology (Tsai, Ou, Wu, Sung, Yen), Department of Internal Medicine, Kaohsiung Medical University Hospital; Graduate Institute of Medicine (Sung, Yen), College of Medicine, Kaohsiung Medical University; Division of Endocrinology and Metabolism, Department of Internal Medicine (Hsieh), Changhua Christian Hospital, Changhua, Taiwan; Graduate Institute of Integrated Medicine (Hsieh), China Medical University, Taichung, Taiwan.
authors.forename: Shun-Jen
authors.initials: SJ
authors.lastname: Chang
authors.affiliation: Department of Internal Medicine (Tseng), Kaohsiung Municipal Ta-Tung Hospital; Department of Kinesiology (Chang), Health and Leisure Studies, National University of Kaohsiung; Division of Rheumatology (Tsai, Ou, Wu, Sung, Yen), Department of Internal Medicine, Kaohsiung Medical University Hospital; Graduate Institute of Medicine (Sung, Yen), College of Medicine, Kaohsiung Medical University; Division of Endocrinology and Metabolism, Department of Internal Medicine (Hsieh), Changhua Christian Hospital, Changhua, Taiwan; Graduate Institute of Integrated Medicine (Hsieh), China Medical University, Taichung, Taiwan.
authors.forename: Wen-Chan
authors.initials: WC
authors.lastname: Tsai
authors.affiliation: Department of Internal Medicine (Tseng), Kaohsiung Municipal Ta-Tung Hospital; Department of Kinesiology (Chang), Health and Leisure Studies, National University of Kaohsiung; Division of Rheumatology (Tsai, Ou, Wu, Sung, Yen), Department of Internal Medicine, Kaohsiung Medical University Hospital; Graduate Institute of Medicine (Sung, Yen), College of Medicine, Kaohsiung Medical University; Division of Endocrinology and Metabolism, Department of Internal Medicine (Hsieh), Changhua Christian Hospital, Changhua, Taiwan; Graduate Institute of Integrated Medicine (Hsieh), China Medical University, Taichung, Taiwan.
authors.forename: Tsan-Teng
authors.initials: TT
authors.lastname: Ou
authors.affiliation: Department of Internal Medicine (Tseng), Kaohsiung Municipal Ta-Tung Hospital; Department of Kinesiology (Chang), Health and Leisure Studies, National University of Kaohsiung; Division of Rheumatology (Tsai, Ou, Wu, Sung, Yen), Department of Internal Medicine, Kaohsiung Medical University Hospital; Graduate Institute of Medicine (Sung, Yen), College of Medicine, Kaohsiung Medical University; Division of Endocrinology and Metabolism, Department of Internal Medicine (Hsieh), Changhua Christian Hospital, Changhua, Taiwan; Graduate Institute of Integrated Medicine (Hsieh), China Medical University, Taichung, Taiwan.
authors.forename: Cheng-Chin
authors.initials: CC
authors.lastname: Wu
authors.affiliation: Department of Internal Medicine (Tseng), Kaohsiung Municipal Ta-Tung Hospital; Department of Kinesiology (Chang), Health and Leisure Studies, National University of Kaohsiung; Division of Rheumatology (Tsai, Ou, Wu, Sung, Yen), Department of Internal Medicine, Kaohsiung Medical University Hospital; Graduate Institute of Medicine (Sung, Yen), College of Medicine, Kaohsiung Medical University; Division of Endocrinology and Metabolism, Department of Internal Medicine (Hsieh), Changhua Christian Hospital, Changhua, Taiwan; Graduate Institute of Integrated Medicine (Hsieh), China Medical University, Taichung, Taiwan.
authors.forename: Wan-Yu
authors.initials: WY
authors.lastname: Sung
authors.affiliation: Department of Internal Medicine (Tseng), Kaohsiung Municipal Ta-Tung Hospital; Department of Kinesiology (Chang), Health and Leisure Studies, National University of Kaohsiung; Division of Rheumatology (Tsai, Ou, Wu, Sung, Yen), Department of Internal Medicine, Kaohsiung Medical University Hospital; Graduate Institute of Medicine (Sung, Yen), College of Medicine, Kaohsiung Medical University; Division of Endocrinology and Metabolism, Department of Internal Medicine (Hsieh), Changhua Christian Hospital, Changhua, Taiwan; Graduate Institute of Integrated Medicine (Hsieh), China Medical University, Taichung, Taiwan.
authors.forename: Ming-Chia
authors.initials: MC
authors.lastname: Hsieh
authors.affiliation: Department of Internal Medicine (Tseng), Kaohsiung Municipal Ta-Tung Hospital; Department of Kinesiology (Chang), Health and Leisure Studies, National University of Kaohsiung; Division of Rheumatology (Tsai, Ou, Wu, Sung, Yen), Department of Internal Medicine, Kaohsiung Medical University Hospital; Graduate Institute of Medicine (Sung, Yen), College of Medicine, Kaohsiung Medical University; Division of Endocrinology and Metabolism, Department of Internal Medicine (Hsieh), Changhua Christian Hospital, Changhua, Taiwan; Graduate Institute of Integrated Medicine (Hsieh), China Medical University, Taichung, Taiwan jehsye@kmu.edu.tw.
authors.forename: Jeng-Hsien
authors.initials: JH
authors.lastname: Yen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001172:Arthritis, Rheumatoid / Q000453:epidemiology; D015331:Cohort Studies; D003882:Dermatomyositis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008180:Lupus Erythematosus, Systemic / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012042:Registries; D012595:Scleroderma, Systemic / Q000453:epidemiology; D017678:Sex Distribution; D012737:Sex Factors; D012859:Sjogren's Syndrome / Q000453:epidemiology*; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult