A major population resource of 474,074 participants in UK Biobank to investigate determinants and biomedical consequences of leukocyte telomere length

Abstract The determinants and biomedical consequences of variation in leukocyte telomere length (LTL), a proposed marker of biological age, are only partially understood. Here we report the creation and initial characterization of LTL measurements in 474,074 participants in UK Biobank. We confirm that older age and male sex associate with shorter LTL, with women on average ∼7 years younger in “biological age” than men. Compared to white Europeans, LTL is longer in African, Chinese and other major ancestries. Older paternal age at birth is associated with longer individual LTL. Higher white cell count is associated with shorter LTL, but proportions of white cell subtypes have weaker associations. Age, ethnicity, sex and white cell count explain ∼5.5% of LTL variance. Using paired samples from 1351 participants taken ∼5 years apart, we show the regression-dilution ratio for LTL is ∼0.65. This novel resource provides major opportunities to investigate LTL and multiple biomedical phenotypes.