Study suggests association between periodontitis and increased blood uric acid levels

Periodontitis is a multifactorial chronic inflammatory condition which results from an imbalanced interaction between periodontal microbiota and host inflammatory response and appears to have a bidirectional link with systemic inflammatory diseases.

Uric acid is a formerly-known antioxidant linked to several inflammatory diseases as an oxidative and pro-inflammatory mediator in pathological conditions. It is crucial to re-evaluate the association between periodontitis and uric acid systematically and locally. Therefore, Lu-wen Ye from Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine in Guangzhou, China, and colleagues systematically evaluated the association between periodontitis and uric acid levels in saliva, blood, and gingival crevicular fluid (GCF) in a systematic review.

For this purpose, the researchers identified and retrieved studies from electronic databases up to January 28, 2023, with gout, hyperuricemia, uric acid, and periodontitis as the keywords. Standardized (SMD) or weighted mean difference (WMD) was calculated using fixed- or random-effect models. Methodological heterogeneity was assessed.

The study led to the following findings:

· One eligible RCT and sixteen observational studies were enrolled, comprising 1354 patients with periodontitis and 989 controls.

· Three sample types for UA detection were involved, including blood (n = 8), saliva (n = 9) and GCF (n = 1).

· Meta-analysis demonstrated an enhanced plasma UA concentration (WMD = 1.00 mg/dL) but a decreased salivary UA level (SMD = -0.95) in periodontitis versus control.

· Statistical heterogeneity among the plasma- and saliva-tested studies were moderate (I2 = 58.3%) and low (I2 = 33.8%), respectively.

Within the present study's limitations, the researchers concluded that there appears to be an association between periodontitis and increased UA concentration in the normouricemia context. However, whether periodontitis and hyperuricemia/gout are associated remains to be determined.

They added, "The amount of uric acid in GCF and saliva seems to be decreased in periodontitis presence in contrast to the change of UA in the blood. The potential mechanisms behind the reversal of changes need additional investigations."

The authors note that most findings are based on a small number of observational studies with substantial heterogeneity and a small sample size, which may compromise the reliability of the conclusions. They feel there is a need for large-scale prospective cohort and interventional studies to validate the findings further.

Reference:

Ye, Lw., Zhao, L., Mei, Zs. et al. Association between periodontitis and uric acid levels in blood and oral fluids: a systematic review and meta-analysis. BMC Oral Health 23, 178 (2023). https://doi.org/10.1186/s12903-023-02900-8