Systemic lupus erythematosus and thyroid disease: a Mendelian randomization study

Objectives To clarify the controversy between systemic lupus erythematosus (SLE) and thyroid disease, our study was designed to determine whether or not thyroid problems are associated with SLE. Methods We obtained the IEU GWAS database for summary information on genome-wide association studies (GWAS) of SLE and thyroid disease (hypothyroidism and hyperthyroidism) in people with European ancestry. Three approaches were employed to assess the causal link between SLE and thyroid disease: MR-Egger, weighted median (WM), and inverse variance weighted (IVW). The pleiotropy and heterogeneity were examined using a variety of techniques, including the MR-Egger intercept, the MR-PRESSO approach, and the Cochran's Q test. Results MR analysis revealed a relationship between SLE and an elevated incidence of hypothyroidism (IVW OR: 1.004, 95% CI: [1.003, 1.005], P = 8.45E-16) and hyperthyroidism (IVW OR: 1.0009, 95% CI: [1.0005, 1.0010], P = 1.30E-5). Neither horizontal pleiotropy nor heterogeneity was detected in the sensitivity analysis. Conclusion Our MR study presents strong evidence demonstrating a link between SLE and an elevated risk of thyroid illness. This could help us learn more about what causes SLE and give people with SLE more thorough thyroid function tests and evaluations.