Association between low bone mineral density and increased α-defensin in salivary fluid among postmenopausal women

OBJECTIVE: This study aims to evaluate the concentration of α-defensin humanneutrophil peptide-1 (HNP-1; a peptide released by neutrophils) in salivary fluidamong postmenopausal women and to compare bone mineral density amongpostmenopausal women with different concentrations of this peptide.METHODS: We consecutively enrolled 61 postmenopausal women. Bone density wasmeasured by dual-energy x-ray absorptiometry, and α-defensin HNP-1 was identifiedby proteomic analysis of salivary fluid specimen.RESULTS: We found a significant difference in bone mineral density amongpostmenopausal women with different concentrations of α-defensin HNP-1 insalivary fluid. In particular, women with higher α-defensin concentrations hadthe lowest bone density in comparison with those with a lower concentration ofdefensin (P = 0.03 between groups). Univariate and multivariate linear regressionanalyses showed a significative inverse relationship between bone mineral densityand age (r = -0.58, β = -0.56) and peak of α-defensin (r = -0.26, β = -0.21).CONCLUSIONS: Low bone mineral density is found in postmenopausal women with high α-defensin HNP-1 concentrations. Therefore, α-defensin HNP-1 could be a novelbiomarker for osteoporosis