Salivary calcium reflects skeletal bone density of heavy smokers

Our recent studies suggest, that elevated calcium concentration of saliva is characteristic of periodontitis. In this study we analyzed the effect of smoking on salivary calcium and bone density by comparing the level of salivary calcium and the ultrasound scale of bone density of heavy smokers to those of non-smokers.

Salivary samples were collected from 603 women (50-62 years) participating in a pre-screen referral program for osteoporosis. Out of this group a total of 577 were accepted for the present study. General health, medications and tobacco smoking were recorded. The group included 487 non-smokers, 37 moderate smokers (1-10 cigarettes per day) and 53 heavy smokers (>10 cigarettes per day). Bone density was measured at the right heel by the quantitative ultrasound technique. Calcium and phosphate concentrations of saliva were measured and expressed as microg/ml of saliva.

The ultrasonographic variables of the heel, broadband ultrasound attenuation (BUA), speed of sound (SOS) and T-score (a standard deviation unit from mean values of healthy young adults) of heavy smokers were significantly lower than those of women who did not smoke (P = 0.007, 0.014 and 0.011, respectively). Salivary calcium concentration of heavy smokers 70.5 (14.6) microg/ml was higher than that of non-smokers 64.0 (14.1) microg/ml (P = 0.001). There were no significant differences in salivary phosphate level or in the salivary flow rate between heavy smokers and non-smokers.

Heavy smokers seem to have lower bone mineral density and higher salivary calcium than their non-smoking counterparts. We suggest that the high salivary calcium concentration of smokers is in connection with skeletal calcium disturbances.