Association between COVID-19 and telomere length: A bidirectional Mendelian randomization study.

Area of Science:

• Genetics
• Epidemiology
• Immunology

Background:

• Observational studies suggested a link between COVID-19 and leukocyte telomere length (LTL), a biomarker of biological aging.
• The causal relationship between COVID-19 and LTL remained unclear, necessitating robust investigation.
• Understanding this relationship is crucial for comprehending the long-term biological impact of COVID-19.

Purpose of the Study:

• To investigate the potential causal association between genetically predicted COVID-19 and leukocyte telomere length (LTL).
• To examine whether genetically predicted LTL influences the risk of developing COVID-19.
• To perform a bidirectional Mendelian randomization analysis to clarify the etiological relationship.

Main Methods:

• A bidirectional Mendelian randomization (MR) study was conducted using genome-wide association study (GWAS) summary statistics.
• Data included critically ill COVID-19 cases (n=1,388,342) and LTL data (n=472,174) from European ancestry.
• Random-effects inverse-variance weighted (IVW) method was the primary analysis, supplemented by MR-Egger, weighted median, and weighted mode approaches.

Main Results:

• No significant causal association was found between genetically predicted COVID-19 and LTL (β=0.0075, p=0.733).
• Conversely, no significant causal association was observed between genetically predicted LTL and COVID-19 risk (OR=1.00, p=0.973).
• Sensitivity analyses using alternative MR methods corroborated the primary findings, indicating robustness.

Conclusions:

• The study found no evidence to support a causal relationship between COVID-19 and leukocyte telomere length in either direction.
• Genetic predisposition to critically ill COVID-19 does not appear to causally influence biological aging as measured by LTL.
• Conversely, genetic factors influencing LTL do not seem to affect the risk of contracting COVID-19.