ADA: Gum Disease Raises Diabetes Risk

By Crystal Phend
SAN FRANCISCO, 10 june 2008-- Periodontal disease and tooth loss may moderately increase the risk of developing type 2 diabetes, according to two longitudinal studies.
Tooth loss was associated with a 14% to 29% elevated risk of incident diabetes among both men and women, according to Kaumudi J. Joshipura, Sc.D., D.P.H., of the Harvard Schools of Public Health and Dental Medicine in Boston, and colleagues.
In their combined analysis of the Nurses' Health Study and the Health Professionals' Follow-Up Study, periodontitis was also associated with a 32% increased risk of incident diabetes among men with a trend for a 20% increased risk among women, they reported at the American Diabetes Association meeting here.
Inflammation is probably to blame for the link found in the study, though "it is a two-way relationship," Dr. Joshipura said.
"It's one more reason periodontal disease should be kept in control," she said. "Dentistry does need to be a part of the diabetic regimen."
Periodontal disease is considered one of the complications of diabetes, although most of the studies to look for a relationship have been cross-sectional. Dr. Joshipura's analysis is among the first prospective studies.
The two prospective cohort studies included 51,529 male health professionals ages 40 to 75 followed for 18 years and 104,064 female health professionals ages 34 to 59 followed for 12 years.
Both groups self-reported periodontal disease in periodic mailed questionnaires.
Among participants without type 2 diabetes at baseline, 3,646 men and 2,343 women developed incident diabetes verified by medical records.
After adjustment for adjusted for number of teeth, age, gender, smoking, family history of diabetes, exercise, obesity, diet, and other factors, the associations with incident diabetes included:
A history of periodontal disease at baseline showed only a weak increased relative risk of 1.08 among men (95% CI 0.96 to 1.21).
More recent periodontal disease during follow-up significantly increased risk among men (RR 1.32, 95% CI 1.15 to 1.51).
Moderate to severe periodontal disease was associated with a nonsignificant 17% increased risk among men (RR 1.17, 95% CI 0.97 to 1.42) and 20% increased risk among women (RR 1.20, 95% CI 0.96 to 1.50).
Periodontal surgery was associated with only a small trend for increased risk among women (RR 1.05, 95% CI 0.93 to 1.19).
Loss of at least one tooth during follow-up increased risk for both women (RR 1.14, 95% CI 1.06 to 1.22) and men (RR 1.25, 95% CI 1.12 to 1.40). The link was even stronger for more recent tooth loss in the two years prior to diabetes incidence (RR 1.18 and 1.29, respectively).
Fewer teeth at baseline also increased the relative risk significantly for all measures among women from 1.15 for 17 to 24 teeth (95% CI 1.05 to 1.24) to 1.34 for 10 or fewer teeth (95% CI 1.21 to 1.48). Likewise, the risk increased from 4% to 12% among men, although the risk was only significant for 10 or fewer teeth.
These associations are what would have been expected from prior studies, Dr. Joshipura said. But she cautioned that the study used self-reported periodontal disease, which may have underestimated the risk.
Notably, though, both periodontal disease and tooth loss were significantly associated with diabetes independent of smoking status (P<0.05), which was reassuring that confounding was not a problem in the study, Dr. Joshipura said.
"We're still at the age where more studies are needed to confirm these relationships," she concluded.
Dr. Joshipura reported no conflicts of interest.
Primary source: American Diabetes Association meetingSource reference:Joshipura KJ, et al "Periodontal disease and incidence of type 2 diabetes mellitus" ADA Meeting 2008; Abstract 889-P.