title: Associations Between Salivary Bone Metabolism Markers and Periodontal Breakdown.
abstract: BACKGROUND
  A dual relationship between glycemic status and bone remodeling was suggested recently. The present study aimed to 1) analyze salivary levels of receptor activator for nuclear factor κ-B ligand (RANKL), osteoprotegerin, osteocalcin, and osteopontin as potential biomarkers of alveolar bone loss and 2) determine whether the glycemic status affects the relationship between bone remodeling markers and periodontal status.
  
  
  METHODS
  Salivary levels of RANKL, osteoprotegerin, osteocalcin, osteopontin, and serum glycosylated hemoglobin A1c, insulin, and glucose were analyzed in 220 participants divided into four groups according to their periodontal health status: 1) 79 participants had at least 14 teeth with probing depth (PD) ≥4 mm (generalized periodontitis [GP]); 2) 65 participants had either two or seven teeth with PD ≥4 mm (two groups of localized periodontitis [LP1 and LP2, respectively]); and 3) 76 participants had no teeth with PD ≥4 mm (non-periodontitis control group).
  
  
  RESULTS
  Salivary concentrations of RANKL, osteocalcin, and osteopontin were higher, and osteoprotegerin was lower in females than in males. Salivary osteoprotegerin concentrations were higher in the GP and LP2 groups than in the control group, whereas RANKL, osteocalcin, and osteopontin were not related with periodontal status. Salivary osteopontin correlated positively with serum and salivary insulin. The association observed between increased osteoprotegerin concentrations and periodontitis was lost after salivary insulin was included into the analyses as a confounding factor.
  
  
  CONCLUSIONS
  Salivary concentrations of bone markers are either affected by glycemic status or detected at very low levels. These factors hinder their use as salivary biomarkers of periodontitis.
authors.affiliation: Institute of Dentistry, University of Turku, Turku, Finland.
authors.forename: Ulvi K
authors.initials: UK
authors.lastname: Gursoy
authors.affiliation: Institute of Dentistry, University of Turku, Turku, Finland.
authors.forename: Joonas
authors.initials: J
authors.lastname: Liukkonen
authors.affiliation: Department of Diagnostic Imaging, Turku University Hospital, Turku, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Jula
authors.affiliation: Institute of Dentistry, University of Turku, Turku, Finland.|National Institute for Health and Welfare, Turku, Finland.
authors.forename: Sisko
authors.initials: S
authors.lastname: Huumonen
authors.affiliation: Unit of Living Conditions, Health, and Wellbeing and Department of Environmental Health in Environmental Epidemiology Unit; National Institute for Health and Welfare; Kuopio, Finland.|Institute of Dentistry, University of Eastern Finland, Kuopio, Finland.|Department of Oral and Maxillofacial Surgery, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Anna L
authors.initials: AL
authors.lastname: Suominen
authors.affiliation: Department of Diagnostic Imaging, Turku University Hospital, Turku, Finland.
authors.forename: Pauli
authors.initials: P
authors.lastname: Puukka
authors.affiliation: Institute of Dentistry, University of Turku, Turku, Finland.|Oral Health Care, Welfare Division, City of Turku, Turku, Finland.
authors.forename: Eija
authors.initials: E
authors.lastname: Könönen
mesh_terms: D016301:Alveolar Bone Loss; D016723:Bone Remodeling; D005260:Female; D006801:Humans; D008297:Male; D015675:Osteocalcin; D053244:Osteoprotegerin; D010518:Periodontitis; D053245:RANK Ligand
chemical_list: D053244:Osteoprotegerin; D053245:RANK Ligand; D015675:Osteocalcin
keywords: Insulin; RANK ligand periodontitis; osteocalcin; osteopontin; osteoprotegerin