Association between periodontitis and diabetes

Background + Aims

• Periodontitis and diabetes share inflammatory pathways, but the relationship between periodontal disease and blood glucose abnormalities before diabetes is diagnosed remains uncertain. Other metabolic abnormalities, including abdominal obesity, abnormal blood fats and hypertension, may also contribute to this relationship.
• This study aimed to:
• • Investigate the association of undiagnosed blood glucose abnormalities, individual cardiometabolic risk factors and metabolic syndrome with periodontitis among Canadian adults without diagnosed or treated diabetes.

Materials + Methods

• This cross-sectional study analysed data from the 2007–2009 Canadian Health Measures Survey. The main sample included 2,807 adults aged 19–79, with 1,383 participants in the fasting subsample used to assess metabolic risk factors.
• Periodontal examinations measured clinical attachment loss, indicating loss of the supporting attachment around teeth. Moderate-to-severe periodontitis was defined using attachment loss ≥4 mm on selected indicator teeth.
• Blood tests measured fasting plasma glucose (FPG) and glycated haemoglobin (HbA1c). Elevated fasting glucose was defined as ≥5.6 mmol/L, encompassing values below and within the diabetes range.
• Metabolic syndrome was defined as at least 3 of 5 abnormalities: abdominal obesity, raised triglycerides, low HDL cholesterol, elevated blood pressure and raised fasting glucose.
• Survey-weighted regression analyses accounted for age, sex, smoking, BMI, ethnicity and dental insurance, followed by household income and education.

Results

• The estimated prevalence of moderate-to-severe periodontitis was 17.9% in the overall study population.
• Within the fasting subsample, periodontitis affected 32.9% of adults with elevated fasting glucose, compared with 14.1% of those below 5.6 mmol/L, before adjustment.
• After accounting for demographic, behavioural and health-related factors, elevated fasting glucose was associated with 60% higher odds of existing periodontitis – prevalence odds ratio (POR) 1.60; 95% CI 1.04–2.45.
• After additionally accounting for income and education, the estimate remained similar but was no longer statistically significant: POR 1.57; 95% CI 0.97–2.53. This leaves uncertainty about an independent association.
• Prediabetes, undiagnosed diabetes and elevated HbA1c, considered separately, were not significantly associated with periodontitis in fully adjusted analyses.
• Abdominal obesity, abnormal blood fats, hypertension and metabolic syndrome also showed no statistically significant adjusted associations.

Limitations