Salivary calcium might be an indicator of osteoporosis in postmenopausal women, according to a prospective study in the Journal of Oral and Maxillofacial Pathology (JOMFP). Compared to pregnant women and healthy controls, postmenopausal women had significantly higher mean salivary calcium levels.
Salivary calcium levels also correlated positively with bone mineral density (BMD) in all three groups. “However, a negative correlation was seen between serum estrogen and salivary calcium only in the postmenopausal group,” wrote the authors from India.
The authors noted a link between reduced estrogen levels and pathogenesis of osteoporosis in postmenopausal women. Estrogen is also known to impact salivary gland functions. An increased understanding of the influence of estrogen on salivary calcium levels over the years prompted the authors to investigate the potential significance of salivary calcium as a biomarker for osteoporosis.
For the cross-sectional study, 90 women were evenly divided into three groups. The healthy controls were aged 20 to 35, with a regular menstrual cycle and a body mass index (BMI) less than 24. Excluded women had a history of systemic illness, drug intake such as hormonal replacement therapy (HRT) and calcium supplements, and tobacco use.
The pregnant group consisted of women aged 20 to 35, with a first pregnancy across all the three trimesters, but without regard to BMI. Exclusion criteria were a history of oral contraceptive use prior to conception, drug intake like HRT and calcium supplements, and tobacco use. The postmenopausal group comprised women at least 45 years old, with the onset of menopause at least 1 year prior to enrolling in the study and BMI under 30, along with two or three parturitions. Women with a history of systemic illness, drug intake, calcium supplements and tobacco use were excluded.
Serum estrogen, salivary calcium and BMD at the heel region were estimated for all study participants. Mean estrogen levels were 115.8 ± 80.18 pg/mmol in the control group, 7729.4 ± 907.6 pg/mmol in the pregnant group and 51.2 ± 74.51 pg/mmol in the postmenopausal group.