Effect of non-surgical periodontal treatment on HbA1c: a meta-analysis of randomized controlled trials

Background: A meta-analysis of randomized clinical trials (RCTs) was conducted to evaluate whether non-surgical periodontal treatment can reduce the HbA1c% level in type 2 diabetic patients. Recent accumulation of RCTs necessitates updating of the findings of previous reviews.

Methods: A search of the literature on English publications was conducted in Cochrane CENTRAL, Medline and EMBASE (until 31 March 2012). An RCT was selected if the study population was type 2 diabetic patients (≥16 years old) diagnosed with periodontitis, and compared HbA1c% change with or without non-surgical periodontal treatment for at least three months of the study duration. Weighted mean differences for pooled data and antibiotic use strata were calculated. Heterogeneity and publication bias were explored.

Results: A total of 358 articles were identified but only six were suitable. Compared to the control group, the pooled analysis (n = 422) showed -0.41% (95% CI: -0.73% to -0.09%, p = 0.013) absolute difference in HbA1c% with treatment. Studies without adjunctive antibiotic had HbA1c% change of -0.64% (95% CI: -1.06% to -0.23%, p = 0.002), but we could not conclude on the effect of adjunctive antibiotic use (p = 0.734). Publication bias was significant with Egger's test (p = 0.014) but not with Begg's test (p = 0.06).

Conclusions: The meta-analysis suggested that non-surgical periodontal treatment was associated with a reduction in HbA1c%.