Baseline epigenetic clock measures in the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA)

DNA methylation (DNAm) can change dynamically in response to intrinsic or external exposures. Characteristic methylation profiles are associated with accelerated biological ageing and poorer health outcomes. CpG methylation levels for individuals within the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA) were previously generated from baseline blood-derived DNA typed on the Infinium MethylationEPIC array. Harnessing this methylation data, epigenetic clock measures were determined, adjusting for chronological age and white blood cell count (CD8T, CD4T, Natural killer, B-cell, Monocytes and Granulocytes).

The NICOLA study was designed to be representative of the Northern Ireland population at Wave 1 and involved the recruitment of 8,283 people from across Northern Ireland. Participants over the age of 50 were recruited. Other household members (spouses/partners) were allowed to take part, even if they were under the age of 50. 2.3% of participants were under the age of 50. Around 50% of participants were aged between 50 and 65, and 10% of participants were over the age of 80 years. This dataset includes epigenetic clock measures for a subset of 1,870 (48% male) participants within the NICOLA cohort, with a mean age of 64.1 ± 9.37 years. The following 10 epigenetic clocks were generated: (± PC)PhenoAge, (± PC)GrimAge, (± PC)Horvath1, (± PC)Hannum, PCDNAmTL and DunedinPACE. ±PC represents the presence or absence of principal component adjustment. This document describes NICOLA's epigenetic clock dataset, which is ~ 2.5Gb in size.