Testing the Causal Association Between Metabolic Syndrome and Periodontitis: A Two-sample Mendelian Randomisation...

Area of Science:

• Genetics
• Epidemiology
• Public Health

Background:

• Observational studies suggest a link between metabolic syndrome (MetS) and periodontitis, but causality remains uncertain due to potential confounding factors and reverse causation.
• Previous research has explored the causal links between individual components of MetS and periodontitis.

Purpose of the Study:

• To investigate the bidirectional causal relationship between metabolic syndrome (MetS) as a whole and periodontitis using Mendelian randomization (MR).
• To provide clinical insights into the potential causal connection between MetS and periodontitis.

Main Methods:

• Utilized genetic instruments from large-scale genome-wide association studies for MetS (n=291,107) and periodontitis (FinnGen: n=195,395; GLIDE: n=45,563) in European populations.
• Employed the inverse-variance weighted (IVW) method for primary causal estimates and conducted sensitivity analyses to ensure result robustness, including multivariable MR and pleiotropy assessments.

Main Results:

• Mendelian randomization analysis using FinnGen data suggested a negative causal association of MetS on periodontitis (OR=0.882, P=0.023), but this was not supported by the GLIDE consortium data (OR=0.986, P=0.697).
• Meta-analysis results did not support a causal association of MetS on periodontitis, and sensitivity analyses indicated no significant pleiotropy.
• No causal association was found in the reverse direction, with periodontitis showing no link to MetS.

Conclusions:

• This Mendelian randomization study concludes that metabolic syndrome (MetS) and periodontitis are not causally related.
• Further research is warranted to elucidate the complex underlying mechanisms that may connect metabolic syndrome and periodontitis.