Good Dental Hygiene May Lower Diabetes Risk

Good dental hygiene is associated with a decreased risk of developing diabetes, according to a study results published in Diabetologia, the journal of the European Association for the Study of Diabetes.

Researchers found that brushing teeth 3 times a day or more is linked to an 8% lower risk of developing diabetes. In addition, the presence of dental disease is associated with a 9% increased risk of developing diabetes. In individuals missing 15 or more teeth, this risk increases to 21%.

Inflammation plays an important role in the development of diabetes, and periodontal disease is common in the general population, the authors explain. Specifically, “Inflammatory reactions are an important cause of diabetes via increasing insulin resistance and endothelial dysfunction,” they said. “Because periodontal disease and poor oral hygiene can provoke transient bacteraemia and systemic inflammation, we hypothesized that periodontal disease and oral hygiene indicators would be associated with the occurrence of new-onset diabetes.”

To test their hypothesis, the researchers collected data from 188,013 subjects from the National Health Insurance System-Health Screening Cohort (NHIS-HEALS) in Korea between 2003 and 2006. In this cohort, 17.5% exhibited periodontal disease. After a median follow-up period of 10 years, 31,545 individuals developed diabetes (estimated event rate, 16.1%; 95% CI, 15.9%-16.3%).

After adjusting for demographics, regular exercise, alcohol consumption, smoking status, vascular risk factors, history of malignancy, and laboratory findings, the investigators found:

• Periodontal disease is positively associated with occurrence of new-onset diabetes (HR, 1.09; 95% CI, 1.07-1.12; P <.001)
• Number of missing teeth (≥15 teeth) is positively associated with occurrence of new-onset diabetes (HR, 1.21; 95% CI, 1.09-1.33; P <.001)
• Frequent tooth brushing (≥3 times/ day) was negatively associated with occurrence of new-onset diabetes (HR, 0.92; 95% CI, 0.89-0.95; P <.001)

“Because periodontal disease is a microbially triggered chronic inflammatory disease, associated systemic inflammatory reactions from the invasion of oral bacteria and release of inflammatory mediators could affect glycaemic control,” the researchers said.

Records were also categorized based on age. In adults younger than 51, brushing teeth 2 times each day was linked to a 10% reduced risk of developing diabetes, while brushing 3 times a day was associated with 14% reduced risk, compared with individuals who brushed once a day or not at all.

In adults over the age of 51, researchers found brushing teeth 3 or more times a day was associated with a 7% decreased risk. However, data showed no difference in the risk for developing diabetes in the older cohort who brushed twice a day, once a day, or not at all.

“Frequent tooth brushing may be an attenuating factor for the risk of new-onset diabetes, and the presence of periodontal disease and increased number of missing teeth may be augmenting factors. Improving oral hygiene may be associated with a decreased risk of occurrence of new-onset diabetes,” the researchers concluded.

Reference

Chang Y, Lee JS, Lee K-J, Woo HG, Song T-J. Improved oral hygiene is associated with decreased risk of new-onset diabetes: a nationwide population-based cohort study [published online March 2, 2020]. Diabetologia. doi: 10.1007/s00125-020-05112-9.