Mechanisms linking periodontitis and diabetes

Background + Aims

• Gingivitis (reversible gum disease) is common in people living with diabetes, especially type 1 diabetes (T1DM). This is due to an exaggerated immune response caused by high blood sugar levels, leading to increased inflammation.
• Gingivitis involves gum inflammation without bone loss, which can be reversed with proper oral hygiene. However, people living with T1DM are more prone to severe gum problems.
• This study looked at specific proteins called biomarkers found in gum fluid that signal inflammation. The goal was to see if these biomarkers differ between people with and without T1DM during experimental gingivitis.
• Understanding these differences could improve early detection of gum disease in people with diabetes.

Materials + Methods

• This study was a secondary analysis of a prospective cohort investigation on experimental gingivitis and T1DM.
• It included 18 Caucasian participants (9 with T1DM and 9 healthy controls), all age- and gender-matched.
• Participants with T1DM had a confirmed diagnosis and had been on insulin therapy for ≥ 12 months, with a mean HbA1c level of 8.1%.
• Healthy subjects had an average HbA1c level of 5.7%.
• Following prophylaxis and oral hygiene instructions, patients refrained from oral hygiene for 21 days, after which clinical assessments and sample collection were performed.
• Gingival crevicular fluid (GCF) samples were collected from 4 quadrants of the mouth at baseline, Day 21, and Day 35, totalling 1440 samples.
• GCF samples were analysed for biomarkers IL-1b, IL-8, MMP-8, and MMP-9 using enzyme-linked immunosorbent assay (ELISA).
• Subgingival bacterial samples were also collected from four mesiobuccal sites using Gracey curettes, and DNA hybridization techniques were used to quantify bacterial species.
• Statistical analysis was conducted to compare biomarker levels and bacterial counts.
  • Area under the curve (AUC) analysis was used to summarize biomarker profiles over time.
  • Pearson’s correlation was applied to explore associations between biomarker levels, bacterial species, and clinical measurements

Results

• Biomarkers:
  • People living with T1DM had significantly higher levels of inflammatory biomarkers (IL-1β, MMP-8, MMP-9) compared to those without diabetes.
  • These markers increased earlier (by Day 7) and stayed higher during the gingivitis period in T1DM patients.
• Gum health:
  • Both groups showed worsening gum health during the no-brushing phase, but T1DM patients had more severe inflammation.
• Bacteria:
  • Bacterial composition in the gums was similar in both groups, indicating that the differences in inflammation were due to the body’s immune response, not the bacteria.

Limitations