Study design and data sources
This study utilized summary-level data from published studies and
databases and all genetic data can be obtained through summary data of
Genome-Wide Association Studies (GWAS), available athttps://gwas.mrcieu.ac.uk/ . Therefore, ethical approval from the
institutional review board is not required for this research.
We conducted a two-sample Mendelian randomization (MR) analysis to
assess the causal relationship between telomere length and the quantity
and function of lymphocytes and their subsets. The summary Genome-Wide
Association Study (GWAS) results for telomere length were derived from
472,174 genetically well-characterized adults in the UK Biobank (UKB).
Telomere length was quantified as the relative
telomere-to-single-gene-copy ratio, and the genetic variations in
telomere length GWAS were adjusted for age and sex(12). The GWAS data
for the quantity of lymphocytes were obtained from a genetic study
focusing on multiple immunological traits in a European population of
7,313 individuals, which identified complex genetic regulation of immune
cells(13). Further details regarding the GWAS summary data for telomere
length and the quantity and function of lymphocytes can be found in
Table S1.