Effect of periodontal therapy on insulin resistance in adults with dysglycemia and periodontitis: a systematic review and meta-analysis

Objectives This systematic review and meta-analysis aimed to address whether non-surgical periodontal therapy (NSPT) can affect insulin resistance, estimated by the homeostasis model assessment (HOMA), in adults with prediabetes or type 2 diabetes mellitus and periodontitis. Materials and methods Six electronic databases and the gray literature were systematically searched for interventional studies reporting NSPT effect on insulin resistance . Seven studies met the eligibility criteria to be synthesized in the qualitative analysis, six reporting change in HOMA-IR, three reporting change in HOMA-%S, and two in HOMA-β. Among them, four were pooled in a meta-analysis of standardized mean difference (SMD) of HOMA-IR; comparing pre- and post-intervention values, three were pooled considering HOMA-%S as outcome, and two studies were summarized considering SMD of HOMA-%S between intervention and control groups. HOMA-β results were qualitatively synthetized. Results With low level of certainty, NSPT significantly reduced HOMA-IR, when compared with pre-intervention data (SMD, −0.35, 95% CI −0.63 to 0.07, p =0.02). There were no significant changes in HOMA-%S or in HOMA-β scores. The level of certainty was very low and moderate, respectively. Conclusions Assertions about a causal link between NSPT and insulin resistance are weak and conflicting, although our more robust results point out to the absence of effect. . Clinical relevance Because further high-quality studies assessing the relationship between periodontitis and insulin resistance are need, the findings of the current systematic review are limited to give recommendations for clinicians. However, while identifying a lack of research in humans with T2D concerning periodontitis and insulin resistance, this study reinforces the need of multicenter well-designed randomized clinical trials.