title: Increased incidence of Sjogren's syndrome in systemic sclerosis: A nationwide population study.
abstract: In the past, there were no studies to evaluate the incidence of Sjogren's syndrome and its relationship with sex and age in patients with systemic sclerosis. In this study, we enrolled 2217 patients with systemic sclerosis and 6485 controls from Taiwan's Registry of Catastrophic Illness database and National Health Insurance Research Database. Every patient with systemic sclerosis was matched to at most three controls by sex, age, month, and year of first diagnosis of systemic sclerosis. Standardized incidence ratio (SIR) of Sjogren's syndrome in patients with systemic sclerosis and 95% confidence interval (95% CI) were calculated. Cox hazard regression was used to calculate the hazard ratio (HR). Both male and female patients with systemic sclerosis had higher incidences of Sjogren's syndrome (SIR: 7.59, 95% CI = 2.97-19.51; SIR: 7.59, 95% CI = 5.56-10.42, respectively). The incidence of Sjogren's syndrome in patients with systemic sclerosis was still higher compared with control when stratified according to age. Age at diagnosis of Sjogren's syndrome was earlier in patients with systemic sclerosis in both male and female groups (p = 0.018; p < 0.001, respectively). Systemic sclerosis was associated with Sjogren's syndrome after adjusting for age, sex, and various autoimmune diseases (HR: 5.98, 95% CI = 4.79-7.47, p < 0.001). Common cytokines, overlapping antibodies, and similar risk alleles were all potential causes of increased incidence of Sjogren's syndrome in systemic sclerosis.
authors.affiliation: a Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University , Kaohsiung , Taiwan .|b Division of Rheumatology, Department of Internal Medicine , Kaohsiung Medical University Hospital , Kaohsiung , Taiwan .
authors.forename: Chia-Chun
authors.initials: CC
authors.lastname: Tseng
authors.affiliation: b Division of Rheumatology, Department of Internal Medicine , Kaohsiung Medical University Hospital , Kaohsiung , Taiwan .|c Institute of Biomedical Sciences, National Sun Yat-sen University , Kaohsiung , Taiwan .|d Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University , Kaohsiung , Taiwan .
authors.forename: Jeng-Hsien
authors.initials: JH
authors.lastname: Yen
authors.affiliation: b Division of Rheumatology, Department of Internal Medicine , Kaohsiung Medical University Hospital , Kaohsiung , Taiwan .
authors.forename: Wen-Chan
authors.initials: WC
authors.lastname: Tsai
authors.affiliation: b Division of Rheumatology, Department of Internal Medicine , Kaohsiung Medical University Hospital , Kaohsiung , Taiwan .
authors.forename: Tsan-Teng
authors.initials: TT
authors.lastname: Ou
authors.affiliation: b Division of Rheumatology, Department of Internal Medicine , Kaohsiung Medical University Hospital , Kaohsiung , Taiwan .
authors.forename: Cheng-Chin
authors.initials: CC
authors.lastname: Wu
authors.affiliation: b Division of Rheumatology, Department of Internal Medicine , Kaohsiung Medical University Hospital , Kaohsiung , Taiwan .|d Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University , Kaohsiung , Taiwan .
authors.forename: Wan-Yu
authors.initials: WY
authors.lastname: Sung
authors.affiliation: e Division of Endocrinology and Metabolism, Department of Internal Medicine , Changhua Christian Hospital , Changhua , Taiwan .|f Graduate Institute of Integrated Medicine, China Medical University , Taichung , Taiwan , and.
authors.forename: Ming-Chia
authors.initials: MC
authors.lastname: Hsieh
authors.affiliation: g Department of Kinesiology , Health and Leisure Studies, National University of Kaohsiung , Kaohsiung , Taiwan.
authors.forename: Shun-Jen
authors.initials: SJ
authors.lastname: Chang
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001323:Autoantibodies / Q000097:blood; D016207:Cytokines / Q000097:blood / Q000276:immunology; D016208:Databases, Factual; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D012595:Scleroderma, Systemic / Q000150:complications / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D012737:Sex Factors; D012859:Sjogren's Syndrome / Q000150:complications / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D013624:Taiwan / Q000453:epidemiology
chemical_list: D001323:Autoantibodies; D016207:Cytokines
keywords: Hazard rate; Sjogren’s syndrome; incidence; retrospective cohort study; systemic sclerosis