title: Relationship between hyposalivation and acute respiratory infection in dental outpatients.
abstract: BACKGROUND
  Hyposalivation may affect respiratory disease because the mouth serves as the entrance to the respiratory apparatus, as well as to the digestive tract. Patients with acute respiratory infection generally have a favorable prognosis and a short natural course. However, in cases in which the host has lowered resistance, such as in elderly patients, the infection may develop into pneumonia.
  
  
  OBJECTIVE
  A prospective study was performed to examine the relationship between hyposalivation, which is common in elderly patients, and acute respiratory infection, which tends to become severe in elderly patients.
  
  
  METHODS
  The subjects were 323 male and female patients ≥40 years old who lived in Utsunomiya City and surrounding areas and regularly visited the Department of Dentistry and Oral Surgery, Tochigi National Hospital. A 6-month follow-up survey was performed to examine development of acute respiratory infection. Age, sex, and known risk factors were also investigated. Hyposalivation was defined as a saliva production (saliva secretion rate) of ≤0.6 ml/min. Multivariate analysis adjusted for age and sex was performed to examine potential risk factors associated with the development of acute respiratory infection.
  
  
  RESULTS
  Data were analyzed for 278 subjects who completed the follow-up survey. The incidence of acute respiratory infection was 60.4%, while hyposalivation was present in 96 subjects (35.5%). Multivariate analysis showed that the incidence of acute respiratory infection was higher in subjects with hyposalivation than in those without hyposalivation (adjusted odds ratio 1.761, p = 0.048).
  
  
  CONCLUSIONS
  The results of this study suggest that hyposalivation may be a risk factor for acute respiratory infection. This also suggests that improvement of hyposalivation might prevent acute respiratory infection.
authors: Department of Dentistry and Oral Surgery, Tochigi National Hospital, Utsunomiya, Japan. hiwabuch@tochi.hosp.go.jp
authors: Hiroshi
authors: H
authors: Iwabuchi
authors: Takashi
authors: T
authors: Fujibayashi
authors: Gen-yuki
authors: GY
authors: Yamane
authors: Hirohisa
authors: H
authors: Imai
authors: Hiroyuki
authors: H
authors: Nakao
mesh_terms: D000208:Acute Disease; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D016001:Confidence Intervals; D003813:Dentistry; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010045:Outpatients; D011446:Prospective Studies; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000209:etiology* / Q000503:physiopathology; D012463:Saliva / Q000378:metabolism*; D012720:Severity of Illness Index; D017678:Sex Distribution; D014987:Xerostomia / Q000150:complications* / Q000175:diagnosis