Association between periodontitis and diabetes

Background + Aims

• Periodontitis is a widespread condition affecting over half of the global adult population, with prevalence increasing with age.
• Severe periodontitis is one of the most common human diseases, contributing significantly to tooth loss.
• Diabetes mellitus (DM), a chronic condition marked by elevated blood glucose levels, is a growing public health concern linked to serious complications.
• Emerging evidence suggests a strong association between periodontitis and diabetes, with both conditions sharing common risk factors.
• Consequently, guidance highlighted the need for periodontal screenings in patients with diabetes and vice versa.
• This study aims to systematically review the prevalence of diabetes in patients with moderate-to-severe periodontitis.

Materials + Methods

• The systematic review followed a pre-established protocol
• The primary research question was: What is the prevalence of diabetes among individuals professionally diagnosed with periodontitis?”
• A comprehensive search was conducted using three online databases with predefined search terms
• Inclusion criteria required studies to:
  • Be in English language
  • Involve human subjects ≥18 years old
  • Have periodontitis diagnosed by dental professionals
  • Report clinically assessed or self-reported diabetes (type 1 or type 2 diabetes)
  • Be observational in design (cohort, case–control, cross-sectional)
  • Reported the prevalence of diabetes within populations with periodontitis.
• Data extraction was conducted by 2 independent reviewers:
  • Prevalence of DM among individuals with periodontitis – Percentages were extracted or calculated by dividing the number of participants with diabetes by the total population with periodontitis.
    • For studies reporting diabetes prevalence across varying periodontitis severities, a weighted mean was calculated, excluding gingivitis data.
    • The prevalence of diabetes among non-periodontitis participants was also extracted when available.
• Data analysis involved:
  • Calculation of a weighted mean prevalence, assigning more weight to larger sample sizes.
  • Sub-analyses were conducted based on diabetes assessment methods (self-reported or clinical) and geographical regions, with at least 2 studies per region required for inclusion.
  • A meta-analysis was conducted to calculate odds ratios (ORs) comparing diabetes prevalence in periodontitis versus non-periodontitis groups. Only studies providing data for both groups were included.
• Heterogeneity across studies was assessed based on study design, participant demographics, geographical location, and diagnostic criteria for both periodontitis and diabetes.
• 2 independent reviewers evaluated the methodological quality of included studies using a standardized scoring system.
• The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was applied to assess the overall strength of evidence.

Results

• 27 papers met the inclusion criteria for the review.
• Prevalence of diabetes among:
  • 83 340 individuals (periodontitis + non-periodontitis): 10.8%
  • 29 594 individuals with periodontitis: 13.1%
  • 53 746 individuals without periodontitis: 9.6%
• The selected studies varied in study design, diagnostic methods for periodontitis and diabetes, and population characteristics.
• Geographically, the highest diabetes prevalence among periodontitis patients was observed in Asia (17.2%), followed by South America (11.9%) and North America (10.3%), with Europe showing the lowest prevalence (4.3%).
• Odds ratios (OR) indicated that individuals with periodontitis had 2.27 times higher odds of having diabetes compared to those without periodontitis.
  • When considering only studies with clinically assessed diabetes, the OR was 1.82
  • When considering self-reported diabetes, the OR was 2.92.
• A dose-response relationship was identified, indicating that diabetes prevalence increases with the severity of periodontitis.
• GRADE assessment of the evidence rated the available evidence as moderate strength demonstrating a weak-to-moderate risk magnitude for the association between periodontitis and diabetes.

Limitations