title: Unstimulated salivary flow rate, pH and buffer capacity of saliva in healthy volunteers.
abstract: OBJECTIVE
  To assess the salivary flow rate, pH, and buffer capacity of healthy volunteers, and their relationships with age, gender, obesity, smoking, and alcohol consumption, and to establish the lower-end value of normal salivary flow (oligosialia).
  
  
  METHODS
  A prospective study was conducted in 159 healthy volunteers (age > 18 years, absence of medical conditions that could decrease salivary flow). Unstimulated whole saliva was collected during ten minutes, and salivary flow rate (ml/min), pH, and bicarbonate concentration (mmol/l) were measured using a Radiometer ABL 520. The 5 percentile of salivary flow rate and bicarbonate concentration was considered the lower limit of normality.
  
  
  RESULTS
  Median salivary flow rate was 0.48 ml/min (range: 0.1-2 ml/min). Age younger than 44 years was associated with higher flow rates (OR 2.10). Compared with women, men presented a higher flow rate (OR 3.19) and buffer capacity (OR 2.81). Bicarbonate concentration correlated with salivary flow rate. The lower-end values of normal flow rate and bicarbonate concentration were 0.15 ml/min and 1.800 mmol/l, respectively. The presence of obesity, smoking, and alcohol consumption did not influence salivary parameters.
  
  
  CONCLUSIONS
  In healthy volunteers, salivary flow rate depends on age and gender, and correlates with buffer capacity. Obesity, smoking, and alcohol use do not influence salivary secretion.
authors.affiliation: Medicina Familiar y Comunitaria, Centro de Atención Primaria, Rafelbunyol, Valencia, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Fenoll-Palomares
authors.forename: J V
authors.initials: JV
authors.lastname: Muñoz Montagud
authors.forename: V
authors.initials: V
authors.lastname: Sanchiz
authors.forename: B
authors.initials: B
authors.lastname: Herreros
authors.forename: V
authors.initials: V
authors.lastname: Hernández
authors.forename: M
authors.initials: M
authors.lastname: Mínguez
authors.forename: A
authors.initials: A
authors.lastname: Benages
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001639:Bicarbonates / Q000378:metabolism; D002021:Buffers; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012463:Saliva / Q000737:chemistry* / Q000378:metabolism; D012472:Salivation / Q000502:physiology*; D012636:Secretory Rate; D012737:Sex Factors
chemical_list: D001639:Bicarbonates; D002021:Buffers