Does periodontitis have any association with mild cognitive impairment?

This study aimed at determining the association between periodontitis and mild cognitive impairment. For this, different electronic databases, including PubMed, Scopus, Embase and Web of Science, were searched for finding the relevant literature. In addition, hand searching of relevant journals was also done to find gray literature.

The systematic review included observational studies only. Accordingly, case-control, cohort and cross-sectional studies were searched. The search strategy was based on PECO framework, wherein the studies which included patients with/without periodontitis and patients with/without mild cognitive impairment (MCI) were included.

A total of 7 studies were included and the data from these studies and the data including bibliographic details, demographic data, data about periodontitis, presence of MCI etc. was extracted from the included articles. The extracted data, was then assessed for heterogeneity using clinical parameters and I² statistical test. Owing to low heterogeneity, fixed-effects model was used for meta-analysis.

Meta-analysis was done to determine the association between periodontitis and MCI and significantly higher incidence of MCI was found in patients with periodontitis OR = OR, 1.70 (95% CI: 1.24–2.32, p < 0.001). A subgroup analysis was done by including the studies comparing incidence of MCI in patients with severe periodontitis, which resulted in even stronger association with an OR of 2.09 (95% CI: 1.49–2.92, p < 0.001). Lastly, periodontal parameters, including CAL, PPD, and PI were compared amongst patients with/without MCI. Significant differences were observed for both CAL and PI, with worsening of values in patients with MCI. Observed mean difference for CAL and PI were 0.44 (95% CI: 0.12–0.75) and 0.72 (95% CI:0.50–0.93), respectively. NS differences were observed for PPD values with a mean difference of 0.21 and 95% CI as −0.08 to 0.49.

Strong association between periodontitis and MCI was observed, indicating periodontitis to be a risk factor for MCI.