Association between periodontitis and diabetes

Background + Aims

• Diabetes mellitus (DM) is a global health concern, affecting 537 million people worldwide and accounting for 10% of healthcare expenditure in developed countries.
• DM increases the risk of periodontitis, with poor glycaemic control tripling the risk of severe periodontitis. Conversely, periodontitis worsens glycaemic control, heightening complications in patients with DM and increasing HbA1c levels over time. Severe periodontitis also poses a risk of developing type 2 DM in non-diabetic individuals. Early diagnosis and periodontal treatment have been demonstrated to be crucial for improving metabolic control and reducing complications. Non-surgical periodontal therapy (NSPT) has been shown to mitigate tooth loss and microvascular issues in DM patients.
• Validated self-reported questionnaires offer a time- and cost-effective method for assessing periodontitis prevalence.
• This study evaluates the association between severe periodontitis and DM using a validated questionnaire in a representative Spanish population sample.

Materials + Methods

• Baseline data were collected between 2008 and 2010 using random cluster sampling from 100 primary healthcare centres, involving 5,072 participants selected from the National Health System registries. A re-evaluation of the same population was conducted between 2016 and 2017 to determine diabetes incidence.
• Participants attended a single visit at their health centres, where data collection included structured questionnaires, oral health questionnaires (an 8-question questionnaire), physical examinations, blood sampling, and oral glucose tolerance tests (OGTT). The questionnaire captured demographic data, health behaviours, medical history, and dietary patterns. Physical assessments included weight, height, waist/hip circumference, and blood pressure, while blood analyses measured glucose, lipid profiles, and HbA1c.
• Diabetes was diagnosed if fasting plasma glucose (FPG) ≥126 mg/dL, 2-hour post-load plasma glucose (PG) ≥200 mg/dL, HbA1c ≥6.5%, or there was known glucose-lowering medication used.
• Prediabetes was defined by FPG 100–125 mg/dL (impaired fasting glucose), 2-hour post-load PG 140–199 mg/dL (impaired glucose tolerance), or HbA1c 5.7%–6.4%.
• For 231 participants, periodontal examinations were conducted by blinded periodontists, measuring clinical attachment loss (CAL), probing pocket depth (PPD), and bleeding on probing (BOP).
• Validated algorithms combining self-reported data, demographics, and risk factors predicted severe periodontitis prevalence.
• Statistical analyses included chi-squared tests, t-tests, and ordinal logistic regression, adjusted for confounders such as age, sex, BMI, smoking, diet, and physical activity.

Results

• Of the 1,751 participants who completed the oral health questionnaire in 2016–2017, 144 new DM cases (8.2%) and 280 prediabetes cases (16.6%) were identified.
• Severe periodontitis prevalence varied depending on the criteria used: 59.0% (Centers for Disease Control and Prevention (CDC)/ American Academy of Periodontology (AAP), 54.7% (≥50% of teeth with CAL ≥5 mm), and 68.8% (≥25% of teeth with PPD ≥6 mm).
• Severe periodontitis was more common in participants with prediabetes or DM compared to normoglycemic individuals (p < .001).
• Subjects with severe periodontitis were older, had higher BMI, and more often presented central obesity, hypertension, dyslipidemia, and cardiovascular events than those without severe periodontitis (all p < .001). They also had lower physical activity levels and a higher prevalence of coronary events, stroke and peripheral vascular disease.
• Logistic regression showed that severe periodontitis was significantly associated with DM. Adjusted models indicated the strongest association using the ≥50% CAL ≥5 mm criteria, with an odds ratio (OR) of 4.9 (95% CI: 2.24–10.72, p < .001).

Limitations