title: Salivary calcium concentration as a screening tool for postmenopausal osteoporosis.
abstract: OBJECTIVE
  Measurements of salivary calcium level may be a useful screening tool for osteoporosis in postmenopausal women. The purpose of this study was to clarify whether this measure is valid compared with dual-energy X-ray (Bone Mineral Density) screening tools in osteoporosis.
  
  
  METHODS
  A case-control study was carried out in 40 postmenopausal women with osteoporosis (T-score ≤ -2.5) and 40 women without osteoporosis (T-score > -1 bone mineral density). Salivary samples were collected and calcium concentrations were measured and expressed as mg/dL. Receiver operating characteristic curve analyses was used to determine the optimal cut-off thresholds for salivary calcium in healthy postmenopausal women.
  
  
  RESULTS
  The cut-off point for salivary calcium was 6.1 mg/dL. The sensitivity and specificity, respectively, for identifying women with osteoporosis, were 67.5 (95%CI 52.33-82.67) and 60% (95%CI 44.62-75.38). The area under curve (AUC) was 0.678 (95%CI 0.56-0.79), the positive predictive value (PPV) was 62.79 (95%CI 47.74-77.84) and negative predictive value (NPV) was 64.86% (95%CI 49.27-80.46). The positive likelihood ratio was 1.688 and the negative likelihood ratio was 0.542.
  
  
  CONCLUSIONS
  Salivary calcium concentration discriminates between women with and without osteoporosis and constitutes a useful tool for screening for osteoporosis.
authors.affiliation: Department of Oral Medicine, Dental School, Guilan University of Medical Sciences, Rasht, Iran. rabiei@gums.ac.ir
authors.forename: Maryam
authors.initials: M
authors.lastname: Rabiei
authors.forename: Irandokht Shenavar
authors.initials: IS
authors.lastname: Masooleh
authors.forename: Ehsan Kazemnejad
authors.initials: EK
authors.lastname: Leyli
authors.forename: Laia Rahbar
authors.initials: LR
authors.lastname: Nikoukar
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D015519:Bone Density; D002118:Calcium / Q000032:analysis*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D015999:Multivariate Analysis; D015663:Osteoporosis, Postmenopausal / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism; D011237:Predictive Value of Tests; D012372:ROC Curve; D012463:Saliva / Q000737:chemistry*
chemical_list: D015415:Biomarkers; D002118:Calcium