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

Area of Science:

• Genetics
• Endocrinology
• Dermatology

Background:

• The relationship between psoriasis and thyroid dysfunction (hyperthyroidism/hypothyroidism) is not well-established, with previous research yielding conflicting results.
• Genetic factors may play a role in the potential association between these conditions.

Purpose of the Study:

• To investigate the causal relationship between psoriasis and thyroid dysfunction using Mendelian randomization (MR).
• To clarify the association between specific types of psoriasis and thyroid disorders.

Main Methods:

• Utilized genome-wide association study (GWAS) data from FinnGen and UK Biobank.
• Employed three MR approaches: MR Egger, weighted median, and inverse variance weighted (IVW).
• Analyzed genetic variants associated with psoriasis, hyperthyroidism, and hypothyroidism.

Main Results:

• No significant association was found between overall psoriasis and hyperthyroidism or hypothyroidism.
• Vulgar psoriasis and guttate psoriasis were associated with hypothyroidism/myxedema (IVW OR = 1.00, P = 2.53E-03).
• Guttate psoriasis showed an association with Graves' disease (IVW OR = 0.86, P = 4.75E-02).
• Hypothyroidism with mucinous edema was not correlated with Graves' disease in the reverse analysis (P = 9.33E-01).

Conclusions:

• Mendelian randomization analysis indicates no overall causal link between psoriasis and thyroid dysfunction.
• Specific psoriasis subtypes, namely vulgar and guttate psoriasis, demonstrate associations with hypothyroidism/myxedema and Graves' disease.
• Clinical vigilance for hypothyroidism and Graves' disease is recommended for patients with guttate psoriasis; monitoring for mucinous edema is crucial for those with vulgar psoriasis and hypothyroidism.