title: Psychological stress has no association with salivary levels of β-defensin 2 and β-defensin 3.
abstract: BACKGROUND
  Recent studies suggest that stress can predispose an individual to the development of periodontal disease, but the exact biological mechanism is unknown. Considering that psychological stress can down-regulate the production of β-defensins (antimicrobial peptides produced in the oral cavity), the aim of the present study was to evaluate the association between stress and salivary levels of β-defensin 2 (HBD-2) and β-defensin 3 (HBD-3).
  
  
  METHODS
  For this purpose, seventy five volunteers, classified as periodontally healthy, were submitted to a psychological evaluation using a validated questionnaire (Questionnaire of Lipp-ISS). Following analysis of the questionnaires, the subjects were divided in two groups (Group A: Absence of stress and Group B: Presence of stress). Unstimulated saliva samples were collected and the concentration of total protein was determined using the BCA method, and the concentrations of HBD-2 and HBD-3 were determined by ELISA.
  
  
  RESULTS
  The levels of total protein did not show a statistically significant difference between the groups. Analyses of HBD-2 and HBD-3 concentrations indicate that the stress condition was not associated with the levels of either peptide in saliva (P=0.3664 for HBD-2 and P=0.3608 for HBD-3).
  
  
  CONCLUSIONS
  In periodontally healthy subjects, HBD-2 and HBD-3 levels are not influenced by stress.
authors.affiliation: Department of Dentistry, University of Taubaté, Taubaté/SP, Brazil Department of Dentistry, Federal University of Minas Gerais, Belo Horizonte/MG, Brazil.
authors.forename: Lilibeth Ferraz de Brito Penna
authors.initials: LF
authors.lastname: Forte
authors.forename: Sheila Cavalca
authors.initials: SC
authors.lastname: Cortelli
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Cortelli
authors.forename: Davi Romeiro
authors.initials: DR
authors.lastname: Aquino
authors.forename: Maria Valéria Costa
authors.initials: MV
authors.lastname: de Campos
authors.forename: Karina
authors.initials: K
authors.lastname: Cogo
authors.forename: Fernando Oliveira
authors.initials: FO
authors.lastname: Costa
authors.forename: Gilson Cesar Nobre
authors.initials: GC
authors.lastname: Franco
mesh_terms: D000222:Adaptation, Physiological; D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D012463:Saliva / Q000276:immunology / Q000378:metabolism*; D012471:Salivary Proteins and Peptides / Q000276:immunology; D013315:Stress, Psychological / Q000276:immunology / Q000378:metabolism*; D055815:Young Adult; D023083:beta-Defensins / Q000276:immunology / Q000378:metabolism*
chemical_list: C422950:DEFB103A protein, human; C106641:DEFB4A protein, human; D012471:Salivary Proteins and Peptides; D023083:beta-Defensins