Biomarkers of bone turnover can be assayed from human saliva

The purpose of this study was to determine if biomarkers of bone turnover [deoxypyridinium (D-PYR) or osteocalcin (OC)] could be detected in human saliva. These biomarkers have been measured in ovariectomized sheep saliva, but not in human saliva. Saliva was collected from 37 women. The bone mineral density of the calcaneus was assessed by quantitative ultrasound and expressed as a T score. Salivary D-PYR and OC concentrations were determined by enzyme-linked immunosorbent assay. Data were analyzed by a Spearman's rho correlation test and factorial analysis of variance was followed by a post hoc Tukey's test. There were significant correlations between age, body mass index, D-PYR, or OC concentration and calcaneus T scores (p<.05), suggesting that saliva could be used as a fluid for assay of human biomarkers of bone turnover. Our data suggest a beneficial use of saliva in situations where a large number of patients are to be screened for metabolic bone diseases.