Impact of periodontal treatment on diabetes management

Background + Aims

• There is a well-established bidirectional relationship between periodontitis and diabetes. Individuals with poorly controlled diabetes are at a higher risk of developing periodontal disease due to the effects of hyperglycaemia on immune function and tissue healing. On the other hand, periodontal disease can exacerbate glycaemic control, leading to increased insulin resistance and worsening metabolic outcomes. The systemic inflammation associated with periodontal disease is believed to contribute to the pathophysiology of diabetes, as inflammatory mediators can interfere with insulin signalling pathways.
• Previous studies have suggested that periodontal treatment may lead to reductions in glycosylated haemoglobin (HbA1c) levels, indicating improved long-term glycaemic control.
• The aim of the study is to systematically review and analyse the effects of subgingival periodontal therapy on glycaemic control, specifically focusing on the reduction of glycosylated haemoglobin (HbA1c) levels in patients with type 2 diabetes mellitus (T2DM).

Materials + Methods

• A systematic review and meta-analysis of randomised controlled trials (RCTs) was conducted to evaluate the effects of subgingival periodontal therapy on glycaemic control in patients with T2DM.
• Nine electronic databases were searched up to February 15, 2023, to identify relevant studies. Studies utilising systemic or local-delivery antimicrobial therapies were excluded.
• Data from the selected studies were extracted, focusing on changes in glycosylated haemoglobin (HbA1c) levels. Meta-analyses were performed using a random-effects model to assess the overall effect of subgingival instrumentation on HbA1c levels.
• Sources of heterogeneity among studies were evaluated using linear meta-regression.
• The risk of bias in individual studies was assessed, and the certainty of evidence was evaluated using the GRADE approach. The quality of the included studies was assessed, and publication bias was evaluated using funnel plots and the Egger test.
• The primary outcome was the change in HbA1c concentration, with results reported as weighted mean differences (WMD) and 95% confidence intervals (CI).

Results

• The review included 12 randomised controlled trials (RCTs), with 11 providing data for quantitative analysis. The meta-analysis involved 1,374 participants from various global regions.
• A significant reduction in HbA1c levels of 0.29% was observed in the treatment group compared to the control group after 6 months (WMD = 0.29, 95% CI: 0.10–0.47; p = .03). Baseline HbA1c levels showed no significant difference between groups (WMD = –0.03, p = .30).
• All studies were assessed as having a high risk of bias, mainly due to a lack of blinding and attrition bias. No evidence of publication bias was found (Egger test p = .07).
• The modest reduction in HbA1c levels is comparable to the effects of some oral antidiabetic medications, supporting the clinical significance of periodontal therapy.

Limitations