BACKGROUND

While observational studies have demonstrated a potential link between inflammatory cytokines and oral diseases, the question of causality is warranting further investigation. This study aimed to comprehensively assess the potential causal role of 41 inflammatory cytokines in common oral diseases.

METHODS

A two-sample Mendelian randomization (MR) study was conducted using the summary statistics from the largest publicly available genome-wide association study (GWAS) for 41 inflammatory cytokines and common oral diseases (indicated by the index of decayed and filled tooth surfaces divided by number of tooth surfaces (DFSS), index of decayed, missing and filled tooth surfaces (DMFS), number of natural teeth, and periodontitis). Inverse variance weighted regression (IVW) was used as the primary method to estimate odds ratios (OR) and 95% confidence interval (CI) for assessing the causal effect. Sensitivity analyses with other four analytical approaches were performed to test the validity of our findings.

RESULTS

Increased levels of hepatocyte growth factor (HGF) and stem cell growth factor beta (SCGF-β) were significantly associated with the risk of DFSS, with the ORs of 1.058 (95% CI: 1.004-1.115, P = .033) and 1.035 (95% CI:1.002-1.069, P = .038), respectively. Interleukin-1 receptor antagonist (IL-1RA) exhibited a negative association with DMFS (OR = 0.934, 95% CI: 0.886-0.985, P = .012). Furthermore, interleukin-9 (IL-9) was associated with in increased risk of periodontitis (OR = 1.148, 95% CI:1.031-1.277, P = .011). Additionally, no significant association was found between inflammatory cytokines and the number of natural teeth. Sensitivity analyses yielded generally consistent results.

CONCLUSIONS

This MR study provides evidence supporting potential causal associations of four inflammatory cytokines (HGF, SCGF-β, IL-1RA, IL-9) with the risk of common oral diseases, which may contribute to the development of more targeted prevention strategies for these diseases.