Assessing the relationship between psoriasis and thyroid dysfunction through two sample MR analysis.

Background: The association between psoriasis and hyperthyroidism/hypothyroidism remains inconclusive, with conflicting findings in prior studies.
Objectives: This study employs Mendelian randomization methods to assess the potential relationship.
Methods: Given the inability to accurately observe the link between psoriasis and thyroid dysfunction, we prioritized utilizing known genetic variants to investigate the potential impacts of the disease.We analyzed data from genome-wide association studies (GWASs), FinnGen, and UK Biobank to extract information on psoriasis, hyperthyroidism, and hypothyroidism. Three MR approaches (MR Egger, weighted median, and inverse variance weighted) were used to scrutinize the causal link.
Results: Our analysis revealed no correlation between psoriasis and hyperthyroidism/hypothyroidism. However,  vulgar psoriasis and guttate psoriasis were associated with hypothyroidism/myxedema (IVW odds ratio (OR) = 1.00, 95% confidence interval (CI) = 1.00-1.00, P = 2.53E-03), and Graves' disease (IVW OR = 0.86, 95% CI = 0.72-1.01, P = 4.75E-02).In a subsequent analysis, we observed that hypothyroidism with mucinous edema showed no correlation with Graves' disease in the opposite(P = 9.33E-01).
Conclusion: This MR analysis suggests no association between psoriasis and thyroid dysfunction, but highlights associations of vulgar/guttate psoriasis with hypothyroidism/myxedema and Graves' disease. In clinical practice, diagnosing guttate psoriasis requires vigilance for associated risks from hypothyroidism and Graves' disease. For patients with both vulgar psoriasis and hypothyroidism, careful monitoring for mucinous edema is crucial, as it may signal a hypothyroid crisis.
(© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)