- This meta-analysis provides evidence that thyroid disorders are more prevalent in patients with myasthenia gravis (MG) than the general population, particularly thyroglobulin antibody (TGAb) positivity, Graves' disease (GD), hyperthyroidism and Hashimoto's thyroiditis (HT).
- Moreover, MG is associated with a higher risk for thyroid autoimmunity.
Why this matters
- Thyroid disorders are more frequently associated with MG compared with other autoimmune diseases; however, the prevalence of thyroid diseases has varied among different studies.
- 39 studies involving 24,927 patients with MG met eligibility criteria after a search on Pubmed, Embase, Web of Science, Cochrane database and other electronic databases.
- Funding: National Natural Science Foundation of China and others.
- In patients with MG, the pooled estimate of thyroid autoimmunity prevalence was 10.1% (95% CI, 6.7-15.1%).
- Subgroups in patients with thyroid autoimmunity showed that positive TGAb (12.6%; 95% CI, 8.1-19.1%) was predominant in patients with MG, followed by GD (6.0%; 95% CI, 4.2-8.5%) and HT (4.6%; 95% CI, 1.9-10.5%).
- The prevalence of thyroid dysfunction in patients with MG was 6.8% (95% CI, 4.6-9.8%).
- The prevalence of hyperthyroidism vs hypothyroidism was higher in patients with MG (5.6%; 95% CI, 3.9-8.0% vs 2.6%; 95% CI, 1.7-4.1%).
- Meta-analysis of 2 studies showed that the risk for thyroid autoimmunity was higher with MG (OR, 2.86; 95% CI, 1.54-5.28; P=.001).
- Risk of confounding factors.
- Heterogeneity among included studies.