Systematic Review and Meta-Analysis Explores Correlation Between Cognitive Disorders and Periodontal Disease and Contributing Factors

Factors such as gender, the disease classification of periodontal disease (PD), and the degree of severity may affect the incidence and risks associated with cognitive disorders in individuals with PD; however, more studies are warranted, according to findings from a study published in Age and Ageing.

The authors indicated that this systematic review with meta-analysis was the first of its kind to evaluate, utilizing meta-regression, the impact of study factors on effect size estimates for dementia and Alzheimer's Disease (AD) in patients with PD.

In this systematic review of cross-sectional and longitudinal cohort studies, researchers sought to investigate the prevalence and incidence of cognitive disorders in individuals with periodontitis.

The authors wrote, “In order to pool the results of individual studies, a meta-analysis will be used to quantify risk of dementia in PD populations, and meta-regression will be used to evaluate the impact of key risk factors.”

To obtain data, researchers searched Medline, EMBASE, and Cochrane databases from the inception of the databases until February 2022. To measure the risk of cognitive decline and dementia/AD, the researchers employed odds ratios (OR), hazard ratios (HR), and relative risks (RR) in various studies.

A total of 39 studies were eligible for meta-analysis: 13 cross-sectional and 26 longitudinal studies. The researchers indicated that PD demonstrated augmented risks of cognitive disorders, and the risk of cognitive decline expanded with PD severity.  For every 10% population rise in females, the risk of cognitive decline increased by 34%, and self-reported PD demonstrated a smaller risk of cognitive disorders compared with clinical classification.

Based on their findings, the authors concluded that overall, PD is more robustly correlated with cognitive decline than dementia A/D. They also noted that gender, the disease classification of PD, and its severity impacted the prevalence and risk estimates of developing cognitive disorders in correlation with the degree and severity of PD. Severe PD was also linked with an augmented incidence and risk of developing cognitive disorders.

To conclude, the authors wrote, “Meta-regression showed that some study factors may influence prevalence and risk estimates of cognitive disorders. More homologous observational evidence with clear adjustments for confounding and selection biases is required to determine the true direction of these associations.”

Lastly, the authors indicated that further studies should employ “Bias-reducing selection methods such as inverse probability weighting and random sampling of large and representative study populations with validated PD assessment tools to reduce the heterogeneity that is reflected in the current literature.”

Source:

Larvin H, Gao C, Kang J, Aggarwal VR, Pavitt S, Wu J. The impact of study factors in the association of periodontal disease and cognitive disorders: systematic review and meta-analysis. Age Ageing. 2023 Feb 1;52(2):afad015. doi: 10.1093/ageing/afad015. PMID: 36794714.