Objective: This study aims to evaluate the concentration of α-defensin human neutrophil peptide-1 (HNP-1; a peptide released by neutrophils) in salivary fluid among postmenopausal women and to compare bone mineral density among postmenopausal women with different concentrations of this peptide.
Methods: We consecutively enrolled 61 postmenopausal women. Bone density was measured by dual-energy x-ray absorptiometry, and α-defensin HNP-1 was identified by proteomic analysis of salivary fluid specimen.
Results: We found a significant difference in bone mineral density among postmenopausal women with different concentrations of α-defensin HNP-1 in salivary fluid. In particular, women with higher α-defensin concentrations had the lowest bone density in comparison with those with a lower concentration of defensin (P = 0.03 between groups). Univariate and multivariate linear regression analyses showed a significative inverse relationship between bone mineral density and 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 novel biomarker for osteoporosis.