title: Association between shift work and periodontal health in a representative sample of an Asian population.
abstract: OBJECTIVE
  The association of shift work with periodontal disease is not well known. We studied the relationship between shift work and periodontitis in a representative sample of an Asian population.
  
  
  METHODS
  Participants were 4597 full-time employees from the Fourth Korean National Health and Nutrition Examination Survey (KNHANES IV). Shifting patterns were categorized into five shifts: daytime (N=3768), evening (N=121), night (N=59), rotating (N=206), and irregular (N=443). Periodontitis was measured with the Community Periodontal Index (CPI). Confounders included age, gender, income, and education. Mediators were frequency of daily tooth brushing, regular dental check-up, smoking, alcohol consumption, diabetes, obesity, and white blood cell count. Multiple logistic regression analyses were performed to evaluate the relationship.
  
  
  RESULTS
  The prevalence of periodontitis in the study population was 32.3%. Shift workers had an elevated odds ratio (OR) of periodontitis [OR 1.22, 95% confidence interval (95% CI) 1.01-1.48] after controlling for confounders. The magnitude of the association between shift work and periodontitis attenuated with adjustment of mediators (smoking and a marker of inflammation). In subgroup analyses, the association was significant (OR 1.42, 95% CI 1.03-1.95) among those ≥45 years. Irregular shift among those ≥45 years showed a significant association (OR 1.79, 95% CI 1.15-2.78).
  
  
  CONCLUSIONS
  Findings of this cross-sectional study suggest that shift work may be associated with periodontitis. Shift workers aged ≥45 years and irregular shift workers aged ≥45 years were risk groups for periodontitis.
authors.affiliation: Department of Preventive and Social Dentistry, School of Dentistry, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul 110-749, Korea. dhhan73@snu.ac.kr.
authors.forename: Dong-Hun
authors.initials: DH
authors.lastname: Han
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Khang
authors.forename: Kyunghee
authors.initials: K
authors.lastname: Jung-Choi
authors.forename: Sinye
authors.initials: S
authors.lastname: Lim
mesh_terms: D000328:Adult; D044466:Asian People; D005260:Female; D006801:Humans; D008297:Male; D010518:Periodontitis / Q000453:epidemiology*; D056910:Republic of Korea / Q000453:epidemiology; D014940:Work Schedule Tolerance