title: Chronic rhinosinusitis increased the risk of chronic periodontitis: a population-based matched-cohort study.
abstract: OBJECTIVE
  Although chronic periodontitis (CP) and chronic rhinosinusitis (CRS) both share immunological disturbances as pathological factors, no prior study has investigated the risk for CP among patients with CRS. This study set out to provide an estimation of risk by utilizing a cohort study design to leverage the statistical power of a population-based dataset in Taiwan.
  
  
  METHODS
  A retrospective cohort study.
  
  
  METHODS
  In total, 13,782 CRS subjects were included in the study cohort and 41,346 subjects were randomly extracted for the comparison cohort. We individually tracked each subject in this study (N = 55,128) for a 5-year period following their index date to identify those subjects who received a subsequent diagnosis of CP. Cox proportional hazards regression analysis was conducted to calculate the 5-year risk of subsequent CP following a diagnosis of CRS among the sampled subjects.
  
  
  RESULTS
  The incidence rate of CP during the 5-year follow-up period was 5.12 (95% confidence interval [CI], 4.95-5.30) per 100 person-years and 3.24 (95% CI, 3.17-3.30) per 100 person-years for the study and comparison cohort, respectively. Cox proportional hazards regression revealed that the hazard ratio for CP during the 5-year follow-up period for subjects with CRS was 1.59 times (95% CI, 1.52-1.67) that of comparison subjects after adjusting for monthly income, geographic region, hypertension, diabetes, coronary heart disease, and hyperlipidemia, and censoring for cases who died during the 5-year follow-up period.
  
  
  CONCLUSIONS
  This study detected an increased risk for CP among patients suffering from CRS. CRS patients should be alerted to pay particular attention to their oral hygiene practices to prevent both CP and its downstream sequelae.
authors.affiliation: School of Public Health, Taipei Medical University Hospital, Taipei.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Keller
authors.forename: Chuan-Song
authors.initials: CS
authors.lastname: Wu
authors.forename: Herng-Ching
authors.initials: HC
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D055113:Chronic Periodontitis / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009910:Oral Hygiene / Q000379:methods*; D011159:Population Surveillance; D015995:Prevalence; D012189:Retrospective Studies; D012220:Rhinitis / Q000150:complications* / Q000453:epidemiology; D018570:Risk Assessment; D012852:Sinusitis / Q000150:complications* / Q000453:epidemiology; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors; D055815:Young Adult