Better care of teeth could also mean greater control of Type 2 diabetes, dentists said at the 68th annual meeting of the American Diabetes Association, now on in San Francisco.
George W. Taylor, Associate Professor of Dentistry, Schools of Dentistry and Public Health, University of Michigan, said, "Several recent studies have shown that having periodontal disease makes those with type 2 diabetes more likely to develop worsened glycemic control and puts them at much greater risk of end-stage kidney disease and death."
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Good glycemic control results in reduced development and progression of diabetes complications. Hence periodontal treatment can perhaps provide an increment in diabetes control and subsequently a reduction in the risk for diabetes complications, Dr. Taylor added.
"One of the many complications of diabetes is a greater risk for periodontal disease,"said Maria E. Ryan, Professor of Oral Biology and Pathology, and Director of Clinical Research, School of Dental Medicine, Stony Brook University, New York, in a recent interview. "If you have this oral infection and inflammation, it's much more difficult to control blood glucose levels." Intensive periodontitis treatment significantly reduces levels of A1C, a measure of glucose control over the prior two to three months.
These links between oral and systemic health may start even before clinical diabetes begins. "We have found evidence that the severity of periodontal disease is associated with higher levels of insulin resistance, often a precursor of type 2 diabetes, as well as with higher levels of A1C, a measure of poor glycemic control of diabetes," she said, according to a press release issued by the ADA.
"In an analysis of the National Health and Nutrition Examination Survey of the U.S. population data from 1988-94, we recently found that people with periodontal disease were twice as likely to have insulin resistance than those without such disease," said Dr. Taylor.
"Genetic testing revealed that 50% of the insulin resistant patients had an IL-1 polymorphism -- in contrast to 20% in the overall population, meaning that they are genetically susceptible to an excessive inflammatory response, and this 50% was the group that had high levels of insulin resistance and more severe periodontal disease," Ryan said.
The presence of the IL-1 polymorphism fits with one theory of how periodontitis worsens glycemic control in type 2 diabetes.
"We think periodontitis may adversely affect glycemic control because the pro-inflammatory chemicals produced by the infection -- such as IL-1-beta, IL-6, and TNF-alpha -- could transfer from the gum tissue into the bloodstream and stimulate cells to become resistant to insulin," said Dr. Taylor. "Then insulin resistance prevents cells in the body from removing glucose from the bloodstream for energy production."
Periodontal (gum) disease is an infection and chronic inflammatory disease of the tissues surrounding and supporting the teeth. It is a major cause of tooth loss in adults. In periodontitis, unremoved plaque hardens into calculus (tartar), gums gradually begin to pull away from the teeth, and pockets form between the teeth and gums. However, people often do not know they have periodontal disease because it is usually painless.
Nearly 21 million Americans have diabetes, a group of serious diseases characterized by high blood glucose levels that result from defects in the body's ability to produce and/or use insulin. Diabetes can lead to severely debilitating or fatal complications, such as heart disease, blindness, kidney disease, and amputation. It is the fifth leading cause of death by disease in the U.S. Type 2 occurs mainly in adults who are overweight and ages 40 and older.
"Just as periodontal disease makes diabetes worse, the reverse also appears to be true, with improvements in periodontal disease benefiting diabetes control," said Dr. Taylor. "We conducted an NIH-funded, randomized clinical trial in 46 people with type 2 diabetes and, 15 months after routine periodontal treatment, found a statistically significant reduction of 0.67% in A1C levels," said Dr. Taylor.
"When glycemia is difficult to control, the physician might consider asking patients when they last saw their dentist, whether periodontitis has been diagnosed and, if so, whether treatment has been completed," said Dr. Ryan. "A consultation with the dentist may be appropriate, to discuss whether periodontal treatment has been successful or whether a more intensive approach with oral or sub-antimicrobial antibiotics is in order because, just as it is difficult to control diabetes while the patient has an infected leg ulcer, the same applies when there's infection and inflammation of the gums."