Causal associations between thyroid dysfunction and COVID-19 susceptibility and severity: A bidirectional Mendelian...

Area of Science:

• Endocrinology
• Genetics
• Infectious Diseases

Background:

• Observational studies suggest a link between COVID-19 and thyroid dysfunction, but causality remains unclear.
• Previous research indicates potential associations between thyroid disorders and COVID-19 risk and severity.

Purpose of the Study:

• To investigate the causal relationship between thyroid function and COVID-19 susceptibility and severity.
• To evaluate the potential of thyroid dysfunction as a risk factor for COVID-19 and vice versa using Mendelian randomization.

Main Methods:

• A bidirectional two-sample Mendelian randomization (MR) analysis was employed.
• Genetic summary statistics for thyroid dysfunction (hypothyroidism, hyperthyroidism) and COVID-19 (susceptibility, hospitalization, severe disease) were utilized.
• Inverse variance-weighted (IVW), weighted-median (WM), MR-Egger, and MR-PRESSO methods were applied for robust analysis.

Main Results:

• No evidence was found for thyroid dysfunction influencing COVID-19 susceptibility or severity.
• COVID-19 susceptibility was identified as a potential risk factor for hypothyroidism (IVW OR=1.577, P=0.022).
• A slight association was observed between COVID-19 hospitalization and hypothyroidism (IVW OR=1.151, P=0.042). No association was found with hyperthyroidism.

Conclusions:

• The findings suggest that COVID-19 may be a risk factor for developing hypothyroidism.
• Enhanced monitoring of thyroid function is advised for individuals infected with SARS-CoV-2.