Results of the research were presented at the International Association for Dental Research meeting in San Francisco.

It is well-known that smoking increases the risk of severe periodontal disease, although researchers have not known how this takes place. They have known that smoking seems to have an adverse effect on the endothelium, the tissue that lines blood vessels, and that a procoagulant called von Willebrand factor (vWF) has been used as an indicator of damage to cells in this layer.

Their study is one of the first to show that von Willebrand factor, which causes platelets to clump around injured endothelial cells and is known to be elevated in certain systemic diseases, also is elevated in smokers with severe periodontal disease, said Sara G. Grossi, clinical director of the UB Periodontal Disease Research Center.

To determine if a relationship exists between von Willebrand factor, periodontal disease and smoking, UB researchers examined 79 subjects aged 25-58. Health and smoking data were collected from all subjects, and periodontal disease status was determined by measuring amount of gum detachment. Persons with diseases known to cause elevated vWF were eliminated from the study.

Subjects were classified as heavy smokers or non-smokers, and as high (periodontal) disease or low disease. From these classifications, four test groups were formed: high disease/heavy smokers; high disease/non-smokers; low disease/heavy smokers and low disease/non-smokers.

Researchers measured concentrations of vWF in blood from each patient to assess evidence of damage to endothelial cells. Results showed that concentrations of the procoagulant were significantly higher in the heavy smokers with severe periodontal disease than in non-smokers with low disease.

Even subjects with low levels of gum disease who smoked had higher concentrations of vWF than persons with high disease levels who didn't smoke, and significantly higher levels than non-smokers with low disease.

"The data indicate that smoking markedly elevates levels of von Willebrand factor in adults," said Grossi. "The results from this study, which suggest that endothelium damage and the vascular system play a role in increasing periodontal disease in smokers, is very exciting and offers new avenues for research into the mechanism by which smoking contributes to severe periodontal disease."