title: Low frequency of toothbrushing practices is an independent risk factor for diabetes mellitus in male and dyslipidemia in female: A large-scale, 5-year cohort study in Japan.
abstract: BACKGROUND
  We previously reported the association between toothbrushing practices and diabetes mellitus (DM) and dyslipidemia (DL) in a cross-sectional study. This study was conducted to clarify whether low frequency of toothbrushing practices is an independent risk factor for DM and DL using a follow-up design.
  
  
  METHODS
  This study was a 5-year retrospective cohort study at St. Luke's International Hospital, Tokyo, Japan. We analyzed study subjects between 30 and 85 years old in 2004, who underwent annual medical examination both in 2004 and 2009. We compared the cumulative incidences of developing DM, DL, hypertension (HT), and hyperuricemia (HUA) between 2004 and 2009 among 3 groups: toothbrushing practices 'after every meal,' 'at least once a day,' and 'less than once a day'. Furthermore, we analyzed odds ratios (ORs) of risk for developing DM and DL by sex after making adjustments for age, obesity, DM, DL, HT, and HUA between two groups: 'after every meal' and 'not after every meal.'
  
  
  RESULTS
  The number of study subjects was 13,070. Of 13,070 study subjects, 575 had DM, 5118 had DL, 2599 had HT, and 1908 had HUA in 2004. We excluded the subjects with each disease in 2004. The cumulative incidences (rates) of DM, DL, HT, and HUA between 2004 and 2009 were 318 (2.5%), 1454 (18.3%), 1108 (10.6%), and 489 (4.4%), respectively. Toothbrushing practices 'not after every meal' was a significant risk factor for developing DM in male [OR: 1.43; 95% confidence interval (CI), 1.040-1.970] and developing DL in female (OR: 1.18; 95% CI, 1.004-1.383) compared with toothbrushing practices 'after every meal.'
  
  
  CONCLUSIONS
  Toothbrushing practices 'after every meal' prevented developing DM in males and DL in females significantly. Toothbrushing practices may be beneficial to reduce developing risk factors for cardiovascular disease.
authors.affiliation: Department of Cardiology, Toranomon Hospital, Tokyo, Japan; Department of Cardiology, St. Luke's International Hospital, Tokyo, Japan; Department of Public Health, Jichi Medical University, Shimotsuke, Japan; School of Medicine, University of Colorado Denver, Aurora, United States. Electronic address: kuwamasa728@gmail.com.
authors.forename: Masanari
authors.initials: M
authors.lastname: Kuwabara
authors.affiliation: Department of Obstetrics, Gynecology and Molecular Reproductive Science, Yokohama City University, Yokohama, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Motoki
authors.affiliation: Department of Preventive Medicine and Public Health, Tokyo Medical University, Tokyo, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sato
authors.affiliation: School of Nursing, Sapporo City University, Sapporo, Japan.
authors.forename: Mizue
authors.initials: M
authors.lastname: Fujii
authors.affiliation: Department of Clinical Nursing, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Ichiura
authors.affiliation: Asa-Gion Dental Clinic, Hiroshima, Japan.
authors.forename: Kazumichi
authors.initials: K
authors.lastname: Kuwabara
authors.affiliation: Department of Public Health, Jichi Medical University, Shimotsuke, Japan.
authors.forename: Yosikazu
authors.initials: Y
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000453:epidemiology*; D050171:Dyslipidemias / Q000453:epidemiology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D033461:Hyperuricemia / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors; D014041:Tokyo / Q000453:epidemiology; D014099:Toothbrushing
keywords: Diabetes mellitus; Dyslipidemia; Epidemiology; Prevention; Toothbrushing