title: Rheumatoid Arthritis Risk Associated with Periodontitis Exposure: A Nationwide, Population-Based Cohort Study.
abstract: BACKGROUND
  The risk of periodontitis (PD) is increased in the patient group of rheumatoid arthritis (RA). RA and PD also shared some pathological mechanism. The aim of this study is to investigate the risk of RA associated with PD exposure.
  
  
  RESULTS
  This study identified 3 mutually exclusive cohorts using the 1999-2010 Taiwanese National Health Insurance Research Database (NHIRD) to investigate the association between PD and the risk of incident RA. All patients with PD in 2000 were identified from the database of all enrollees as the PD cohort. From the representative database of 1,000,000 enrollees randomly selected in 2010 (LHID2010), individuals without any periodontal disease (PO) during 1999-2010 were selected as the non-PO cohort. Individuals who were not included in the non-PO cohort and received dental scaling (DS) no more than two times per year during 1999-2010 were selected as the DS cohort from LHID2010. Using cox proportional regression analysis, hazard ratios (HRs) with 95% confidence intervals (Cis) were calculated to quantify the association between PD exposure and RA development. In the three-group comparison using the non-PO cohort as reference, we found that the risk of RA was higher in the PD and DS cohorts (HRs, 1.89 and 1.43; 95% CIs, 1.56-2.29 and 1.09-1.87, respectively). For comparisons between two cohorts, the PD cohort had a higher risk of RA than the non-PO and DS cohorts (HRs, 1.91 and 1.35; 95% CIs, 1.57-2.30 and 1.09-1.67, respectively).
  
  
  CONCLUSIONS
  PD was associated with an increased risk of RA development.
authors.affiliation: Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Yin-Yi
authors.initials: YY
authors.lastname: Chou
authors.affiliation: Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Kuo-Lung
authors.initials: KL
authors.lastname: Lai
authors.affiliation: Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan; School of Medicine, Chung-Shan Medical University, Taichung, Taiwan; Institute of Biomedical Science and Rong Hsing Research Center for Translational Medicine, Chung-Hsing University, Taichung, Taiwan; Department of Medical Education, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Der-Yuan
authors.initials: DY
authors.lastname: Chen
authors.affiliation: Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Ching-Heng
authors.initials: CH
authors.lastname: Lin
authors.affiliation: Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan; School of Medicine, Chung-Shan Medical University, Taichung, Taiwan; Institute of Biomedical Science and Rong Hsing Research Center for Translational Medicine, Chung-Hsing University, Taichung, Taiwan; Department of Medical Education, Taichung Veterans General Hospital, Taichung, Taiwan; Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan; Institute of Public Health and Community Medicine Research Center, National Yang-Ming University, Taipei, Taiwan; Institute of Hospital and Health Care Administration, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Hsin-Hua
authors.initials: HH
authors.lastname: Chen
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000453:epidemiology* / Q000209:etiology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D010518:Periodontitis / Q000150:complications* / Q000503:physiopathology; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology