Salivary cystatin activity and cystatin C in natural and experimental gingivitis in smokers and non-smokers

Background: Recent studies show that subjects with natural gingivitis or pe riodontitis have elevated levels of salivary cystatins compared to periodon tally healthy individuals, Increased glandular output of cystatins in infla mmatory conditions suggests an active, most likely protective, role for the se proteins in inflammatory processes. Furthermore, it has been shown that the development of gingival inflammation is suppressed in smokers during ex perimental gingivitis. Aims: The purpose of the present study was to investigate whether (i) the l evels of salivary cystatins in natural gingivitis are related to smoking st atus, and (ii) to study whether experimentally induced gingivitis is associ ated with changes in salivary cystatin levels, in both smokers and non-smok ers. Material and Methods: Whole saliva samples were taken in relation to natura l gingivitis, gingival health and 14-day experimental gingivitis in 25 non- dental students (14 non-smokers and 11 smokers). The salivary flowrate was determined. Samples were analyzed for levels of protein, cystatin and cysta tin-C. Results: Salivary flow and protein concentrations in cleared human whole sa liva samples of non-smokers and smokers were not different from each other at any timepoint during the trial. With regard to cystatins, the results sh owed that in the state of natural gingivitis cystatin activity is lower in smokers as compared to non-smokers. In smokers, the resolution of natural g ingivitis to the state of gingival health did not result in a change of cys tatin activity and levels of cystatin C. At the end of the 14-day experimen tal gingivitis period, smokers showed a decrease in cystatin activity and c ystatin C as well as lower outputs of cystatin activity and cystatin C. Conclusion: Smoking is associated with lower cystatin activity and output o f cystatin C during gingival inflammation.