title: Salivary flow rate, buffer capacity, and urea concentration in adolescents with type 1 diabetes mellitus.
abstract: BACKGROUND
  The objective of the study was to analyze salivary flow rate, urea concentration, and buffer capacity in adolescents with type 1 diabetes mellitus (type 1 DM) in two different stages.
  
  
  METHODS
  This study was performed on adolescents (14-19 years), allocated between two groups: type 1 DM group comprised 32 adolescents with type 1 DM, and non-type 1 DM group comprised 32 nondiabetics. The adolescents in type 1 DM group were evaluated at a baseline (T0) and after 15 months (T1), and those in non-type 1 DM group were only evaluated at T0. Diabetic status was determined by glycosylated hemoglobin (GHb) and capillary glucose tests. Measurement of salivary flow was performed by means of stimulated saliva (SSFR) collection. The buffer capacity (BC) was determined, and analysis of urea salivary concentration was performed using the colorimetric method.
  
  
  RESULTS
  At T0, there were significant differences between diabetics and nondiabetics for SSFR and BC (p<0.05). In diabetics, SSFR was 0.790 mL/min in T0 and 0.881 mL/min in T1 (p>0.05). BC at T0 was 4.8, and at T1, it was 3.9 (p=0.000). Urea concentration mean value had a significant decrease at T1 (28.13) compared with T0 (34.88) (p=0.013). There was a negative correlation between SSFR and urea salivary concentration at both T0 (r=-0.426, p≤0.05) and T1 (r=-0.601, p≤0.01).
  
  
  CONCLUSIONS
  In adolescents with type 1 DM, hyposalivation at T0 was associated with an increase in urea salivary concentration. At T1, hyposalivation was associated with a reduction in BC, and an increase in salivary urea.
authors.forename: Ivana Maria
authors.initials: IM
authors.lastname: Saes Busato
authors.forename: Carlos Cesar De
authors.initials: CC
authors.lastname: Antoni
authors.forename: Thiago
authors.initials: T
authors.lastname: Calcagnotto
authors.forename: Sérgio Aparecido
authors.initials: SA
authors.lastname: Ignácio
authors.forename: Luciana Reis
authors.initials: LR
authors.lastname: Azevedo-Alanis
mesh_terms: D000293:Adolescent; D000328:Adult; D002021:Buffers; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D011379:Prognosis; D012463:Saliva / Q000737:chemistry* / Q000378:metabolism*; D012636:Secretory Rate; D014508:Urea / Q000378:metabolism*; D055815:Young Adult
chemical_list: D002021:Buffers; D006442:Glycated Hemoglobin; D014508:Urea