Bacteria From Gum Infections Associated With Diabetes, Chronic Lung Disease, UB Studies Find

VANCOUVER, British Columbia -- Diabetes and chronic lung disease can be added to the growing list of systemic diseases and conditions associated with bacteria from infected gums, new studies from the University at Buffalo School of Dental Medicine have shown.

The findings from both studies were presented here today (March 13) at the combined meeting of the American Association of Dental Research and International Association of Dental Research.

To investigate the association of periodontal disease with diabetes, a research team headed by Sara G. Grossi, D.D.S., UB senior research scientist, concentrated on insulin resistance, a known precursor of active diabetes, in which cells do not absorb insulin from the blood stream.

As their study group, the researchers used 11,198 subjects from the Third National Health and Nutrition Examination Survey (NHANES III) conducted from 1988-94, including all non-diabetic NHANES participants between the ages of 20 and 90 who had at least six natural teeth.

They assessed information on periodontal status, defined as degree of gum detachment from bone, along with fasting-insulin and fasting-glucose levels, which were combined to establish an index of insulin resistance. Persons with known diabetes or with a blood glucose level that reached diabetic levels were excluded from the analysis.

Analysis showed that the index of insulin resistance increased as severity of periodontal disease increased. The relationship was not affected by age, gender, body-mass index (a measure of obesity) or smoking. To clarify the relationship further, the researchers separated the study group into overweight versus non-overweight, using a body mass index of 27 as the dividing line. Weight is an independent risk factor for insulin resistance and diabetes.

Results showed that those with severe periodontal disease (gum detachment), regardless of weight, have a higher index of insulin resistance than those with little or no disease.

"Gram-negative periodontal infections are significantly associated with insulin resistance in non-diabetics," Grossi said. "We know that when diabetics have an acute infection, their diabetes goes out of control. Gram-negative bacteria produce a very potent toxin called LPS, which probably interferes with the action of insulin and is responsible for maintaining a chronic state of insulin resistance in people with gum infections," she said.

The study on the relationship between periodontal infection and chronic lung disease was designed to follow up earlier reports of a link between poor oral hygiene, gum disease and chronic lung disease, also using data from NHANES III.

Frank Scannapieco, D.M.D, Ph.D., assistant professor of oral biology, analyzed data from 13,792 adults concerning the incidence of pneumonia, asthma, bronchitis and/or emphysema and the condition of their oral health, using degree of gum detachment from bone as an indicator.

Results showed that persons with chronic lung conditions had more gum detachment than those with no lung disease, after correction for age, gender, race, ethnicity, education, income, frequency of dental visits, smoking and alcohol consumption.

There also was a direct correlation between the amount of detachment and lung-disease risk. Subjects with gum detachment that exceeded 2 mm had a 40 percent greater risk of developing lung disease than those with attachment loss of less than 2 mm, results showed.