Salivary calcium as a diagnostic tool for screening of osteoporosis in postmenopausal women

Background: Women's health undergoes physiological, pathological and psychological changes after menopause. Reduced estrogen levels have been implicated in the pathogenesis of osteoporosis in postmenopausal women. Estrogen is also known to affect the salivary gland functions. To understand the association between serum estrogen, osteoporosis and salivary calcium, the present cross-sectional study was undertaken. Aim: The aim of this study is to determine salivary calcium levels and its use for the diagnosis of osteoporosis in postmenopausal women. Methodology: Ninety individuals divided into three groups of healthy controls, pregnant women and postmenopausal women were selected. Serum estrogen, salivary calcium and bone mineral density (BMD) at the heel region were estimated. Statistical analysis using the Mann–Whitney U-test was done to compare the results within the groups. Results: Mean estrogen levels were 115.8 ± 80.18 pg/mmol in control group, 7729.4 ± 907.6 pg/mmol in pregnant group and 51.2 ± 74.51 pg/mmol in postmenopausal group, respectively. The mean salivary calcium in control, pregnant and postmenopausal groups was 3.12 ± 0.63, 3.19 ± 0.62 and 7.12 ± 0.79 μg/dl, respectively. Paired comparison within the groups showed high statistical significance ( P = 0.0000) in the salivary calcium levels. The mean BMD of −2.3 (standard deviation [SD] ± 0.83) in the postmenopausal group was significantly lower than −0.6 (SD ± 0.99) and −0.2 (SD ± 1.42) of pregnant and control groups, respectively. Conclusion: A negative correlation was found between estrogen and bone density. A significant difference in salivary calcium was noted in the study groups, highlighting the role of salivary calcium in the detection of early bone changes in postmenopausal women.