Telomere Length and COVID-19 Outcomes: A Two-Sample Bidirectional Mendelian Randomization Study.

Area of Science:

• Genetics
• Epidemiology
• Infectious Diseases

Background:

• Observational studies suggest a link between short leukocyte telomere length (LTL) and severe COVID-19.
• The causal relationship between LTL and COVID-19 outcomes requires further investigation.

Purpose of the Study:

• To investigate the causal association between genetically predicted LTL and COVID-19 susceptibility or severity using Mendelian randomization.

Main Methods:

• A two-sample Mendelian randomization (MR) study was employed.
• Genetically predicted LTL was derived from genome-wide association studies (GWAS).
• COVID-19 outcome data were analyzed from the COVID-19 Host Genetics Initiative.

Main Results:

• Genetically predicted LTL showed no significant association with COVID-19 susceptibility (OR: 0.94; p=0.202).
• Genetically predicted LTL also showed no significant association with COVID-19 severity (OR: 0.85; p=0.099).
• Sensitivity analyses using various MR methods and datasets confirmed these null findings.

Conclusions:

• Genetic evidence does not support shorter LTL as a causal risk factor for COVID-19 susceptibility or severity.
• The findings suggest that the observed association in observational studies may not be causal.