title: The impact of masticatory ability as evaluated by salivary flow rates on obesity in Japanese: The Toon health study.
abstract: OBJECTIVE
  This study examined the associations of masticatory ability evaluated by chewing-gum-stimulated salivary flow rate with anthropometric indices among a general Japanese population.
  
  
  METHODS
  In total, 921 Japanese men and women aged 30-79 years participated in this cross-sectional study. Saliva production was stimulated by 5 min of gum chewing, then collected; salivary flow rate was calculated as g/min. Overweight, abdominal obesity in terms of waist circumference (WC), and waist-hip ratio (WHR), and elevated skinfold thickness statuses were determined.
  
  
  RESULTS
  The multivariable odds ratio and 95% confidence intervals of overweight, abdominal obesity (WC, WHR), and elevated skinfold thickness status for highest vs. lowest quartile of salivary flow rate were 0.59 (0.37-0.95, P for trend = 0.02), 0.65 (0.43-0.98, P = 0.03), 0.54 (0.35-0.83, P < 0.01), and 0.61 (0.39-0.96, P < 0.01), respectively. The linear trends of multivariable-adjusted means of BMI, WC, WHR, and skinfold thickness according to quartiles of salivary flow rate did not vary after stratification by overweight status.
  
  
  CONCLUSIONS
  Higher stimulated salivary flow rate, a surrogate marker for mastication ability, was associated with lower prevalence of overweight, abdominal obesity (whether WC- or WHR-defined), and elevated skinfold thickness among the general Japanese population.
authors.affiliation: Department of Basic Medical Research and Education, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan.
authors.forename: Koutatsu
authors.initials: K
authors.lastname: Maruyama
authors.affiliation: Department of Basic Nursing and Health Science, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Nishioka
authors.affiliation: Department of Public Health, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Miyoshi
authors.affiliation: Department of Basic Nursing and Health Science, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Higuchi
authors.affiliation: Department of Public Health, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Mori
authors.affiliation: Center for Sleep Medicine, Ehime University Hospital, Shitsukawa, Toon, Ehime, Japan.
authors.forename: Sakurako
authors.initials: S
authors.lastname: Tanno
authors.affiliation: Department of Basic Nursing and Health Science, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan.
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Tomooka
authors.affiliation: Department of Public Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Eguchi
authors.affiliation: Department of Public Health, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Furukawa
authors.affiliation: Department of Basic Nursing and Health Science, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Saito
authors.affiliation: Department of Clinical Laboratory Science, Faculty of Health Care, Tenri Health Care University, Tenri, Nara, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Sakurai
authors.affiliation: Nishida Wataru Diabetes Clinic, Matsuyama, Ehime, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Nishida
authors.affiliation: Department of Molecular and Genetic Medicine, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan.
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Osawa
authors.affiliation: Department of Public Health, Juntendo University Graduate School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tanigawa
mesh_terms: D000328:Adult; D044466:Asian People / Q000706:statistics & numerical data; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008409:Mastication / Q000502:physiology*; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology / Q000378:metabolism*; D012463:Saliva / Q000378:metabolism*; D012636:Secretory Rate; D055105:Waist Circumference