Studies in Pima and Pueblo Indians Underscore Unhealthy Relationship Between Gum Disease and Diabetes

SAN DIEGO -- Studies conducted in two Native American populations with a high prevalence of both Type 2 diabetes and gum disease have underscored the importance of oral health in controlling adult diabetes.

Results of the studies were presented here beginning on Friday, March 8, at the International Association of Dental Research meeting.

Researchers from the University at Buffalo School of Dental Medicine, working with the San Felipe and Santo Domingo communities of the Pueblo Indians in Santa Fe, N.M., found that reducing gum infections with antibiotics also improved diabetes control, based on concentrations of glycated hemoglobin, a marker of blood sugar control.

Another study involving Pima Indians from the Gila River Indian community in Mesa, Ariz., who have the highest reported rates of both diabetes and gum disease, showed that glycated hemoglobin levels don't fall, even when sufferers have lost all of their teeth and thus no longer have periodontal disease.

UB dental researchers and others have shown in previous studies that a relationship clearly exists between periodontal disease and diabetes. Sara Grossi, D.D.S., UB clinical assistant professor of oral biology and supervising scientist on both current studies, said she has come to believe periodontal disease may be the most important of all the factors known to contribute to diabetes onset, including age, gender, obesity and smoking.

The Pueblo community study involved 75 persons with Type 2 diabetes and severe periodontal disease who were randomized into four treatment groups. Each group received the same active antibiotic to treat their gum disease, but the regimen differed. Blood samples were taken at three, six, nine and 12 months to evaluate levels of glycated hemoglobin, which indicated the state of glucose control.

Results showed levels of glycated hemoglobin could be reduced and maintained at a reduced level most effectively on a regimen combining a repeated oral antibiotic with a topical antibiotic applied to the gums every three months.

"The study shows that in this group of severe diabetics we were able to increase glucose control with repeated treatment of their periodontal infection," Grossi said. "This reduction in glycated hemoglobin was equal to and independent of any reduction brought about by diabetes medication."

The Pima Indian study was a retrospective analysis of data collected from 818 subjects in the Pima Indian Epidemiological Study conducted by UB in conjunction with the Indian Health Service. Participants, all of whom had Type 2 diabetes, were divided into three groups depending on their dental status: no teeth, severe gum disease, and mild or moderate gum disease.

Grossi noted that in this population, tooth loss is due almost entirely to periodontal disease because the high level of natural fluoride in the region's water supply prevents the cavities that contribute to tooth loss in other populations.

Results showed that those who have lost all of their teeth to gum disease showed equal or higher levels of glycated hemoglobin as those with severe periodontal disease. Those with no teeth also had had diabetes longer than those with severe gum disease.

"This shows that once the cascade of severe periodontal infection has taken its toll on the chronic disease of diabetes, it is too late to turn it back," said Grossi.

"This underscores the importance of prevention and early treatment of periodontal disease in persons at high-risk of diabetes, and even those at moderate risk," she said. "We need to do much more in treating oral infections early in these populations."

Additional researchers on the Pueblo study were Fred Skrepcinski, D.D.S., of the Indian Health Service; Alex Ho, statistician in the UB Department of Oral Biology; Steve Garrett, D.D.S., and Wess Ortolano of Atrix Laboratories, Inc, and Robert J.Genco, D.D.S., Ph.D., UB vice provost, SUNY Distinguished Professor and chair of the UB Department of Oral Biology. The study was supported by grants from the Division of Health and Human Services and Atrix Laboratories, Inc.

Additional researchers on the Pima study were Stanley Shih, a UB Dental student, and Ho.