Mendelian randomization analysis reveals no causal relationship between thyroid function and sarcopenia-related...

Area of Science:

• Endocrinology
• Gerontology
• Genetics

Background:

• Emerging research suggests a potential link between thyroid function and sarcopenia.
• However, the precise mechanisms and causal relationship remain unclear.
• Sarcopenia is characterized by loss of muscle mass and strength, impacting mobility and health in aging populations.

Purpose of the Study:

• To investigate the potential causal relationship between thyroid function and sarcopenia-related traits.
• To examine the influence of thyroid function on hand-grip strength, appendicular lean mass (ALM), and walking pace.
• To assess whether sarcopenia-related traits causally influence thyroid function.

Main Methods:

• Employed a bi-directional two-sample Mendelian randomization (MR) design.
• Utilized genetic instruments for thyroid function from a large meta-analysis (271,040 participants).
• Sarcopenia trait data (hand-grip strength, ALM, walking pace) were sourced from UK Biobank GWAS (up to 461,026 European participants).
• Inverse-variance weighted (IVW) method and sensitivity analyses were performed.

Main Results:

• MR analyses, after Bonferroni correction, showed no significant causal effect of thyroid function on sarcopenia traits.
• Reverse MR analysis also found no evidence that sarcopenia traits causally influence thyroid function.
• Sensitivity analyses corroborated the primary findings from the IVW method.

Conclusions:

• The study does not support a direct causal link between thyroid function and sarcopenia-related traits.
• Observed associations in epidemiological studies might be attributed to confounding factors or shared biological pathways.
• Further research is needed to elucidate the complex interplay between thyroid health and muscle function.