Causal association between diabetes mellitus and rheumatoid arthritis: A bidirectional Mendelian randomization study

Background

Studies reported an association between rheumatoid arthritis and Diabetes mellitus. We sought to assess the causal association between rheumatoid arthritis and Diabetes mellitus risk using a two-way two-sample Mendelian randomization (MR) analysis.

Methods

Data on Diabetes mellitus and rheumatoid arthritis were obtained from the GWAS genome-wide database, and the MR method was used to explore the bidirectional causal association, the inverse variance weighted (IVW) method was used as the primary analysis method, and sensitivity analysis was performed.

Results

IVW results and MR-Egger method indicate that there is a significant correlation between Diabetes mellitus and rheumatoid arthritis (IVW: P = 0.002, OR = 1.057, 95%CI: 1.02–1.096, MR-Egger: P = 0.037, OR = 1.096, 95%CI: 1.006–1.194), MR-Egger intercept analysis shows that the P-value is 0.362 (>0.05), IVW results showed a significant association between rheumatoid arthritis and Diabetes mellitus (IVW: P = 2.65 × 10–9, OR = 1.797, 95%CI: 1.481–2.180), MR-Egger intercept analysis shows that the P-value is 0.221 (>0.05).

Conclusion

The results confirm that Diabetes mellitus and rheumatoid arthritis have a two-way causal chain, and it is necessary to strengthen bidirectional surveillance.