Association Between Telomere Length and Thyrotoxicosis: Insights from a Two-sample Mendelian Randomization Study

Area of Science:

• Endocrinology
• Genetics
• Aging Biology

Background:

• Thyrotoxicosis results from excess thyroid hormones, but its connection to aging is unclear.
• Telomere length (TL) indicates cellular senescence and genome stability, and is linked to various diseases.

Purpose of the Study:

• To investigate the causal effect of genetically predicted telomere length (TL) on thyrotoxicosis risk.
• To explore the role of cellular aging in the etiology of thyrotoxicosis.

Main Methods:

• A two-sample Mendelian randomization (MR) study design was employed.
• Genetic instruments for TL were derived from a large GWAS (n > 470,000) in European ancestry.
• Thyrotoxicosis data utilized summary statistics from the FinnGen release (≈4,000 cases, >210,000 controls).

Main Results:

• Longer genetically predicted TL was associated with a significantly lower risk of thyrotoxicosis.
• Results were consistent across multiple MR estimators (IVW, MR-Egger, weighted median, MR-PRESSO, MR-RAPS).
• Sensitivity analyses confirmed no significant directional pleiotropy and supported causality from TL to thyrotoxicosis.

Conclusions:

• Genetically predicted longer telomere length (TL) may protect against thyrotoxicosis.
• Cellular aging, as indexed by TL, appears to be a contributing factor to thyrotoxicosis susceptibility.
• Further research is warranted to elucidate the mechanistic links between telomere biology and thyroid dysfunction.