Deciphering thyroid function and CIMT: a Mendelian randomization study of the U-shaped influence mediated by...

Area of Science:

• Endocrinology
• Cardiovascular Medicine
• Genetics

Background:

• Carotid intima-media thickness (CIMT) is a key indicator for atherosclerosis and cardiovascular disease (CVD) risk.
• The precise causal link and mechanisms between thyroid function and CIMT require further investigation.

Purpose of the Study:

• To investigate the causal relationship between thyroid function and CIMT using Mendelian Randomization (MR).
• To explore potential mediating roles of lipid profiles in the thyroid function-CIMT association.

Main Methods:

• Two-sample MR analysis utilizing data from the Thyroidomics Consortium and UK Biobank.
• Inverse variance weighting (IVW-MRE) was the primary analytical approach.
• Multivariate MR was employed to assess mediation by lipid traits.

Main Results:

• Lower Free Thyroxine (FT4) levels within the normal range were causally associated with increased CIMT.
• No significant associations were found for Free Triiodothyronine (FT3), TSH, or TPOAb with CIMT.
• Apolipoproteins A-I and B were identified as potential mediators in the thyroid function-CIMT pathway.

Conclusions:

• Establishes a causal link between thyroid function and CIMT, highlighting the importance of thyroid monitoring for CVD risk.
• Suggests thyroid hormone supplementation may be beneficial for reducing CIMT in hypothyroid patients.
• Informs targeted strategies for managing thyroid dysfunction to prevent cardiovascular complications.