Epigenetic age oscillates during the day (Neu 30 yr old)

Since their introduction, epigenetic clocks have been extensively used in aging and human disease research. In this study, we reveal an intriguing pattern: epigenetic age predictions display a 24-hour periodicity. These paradoxical age oscillations can be attributed to variations in blood cell type composition and epigenomes, both of which demonstrate circadian rhythmicity. This discovery emphasizes the significance of factoring-in the time of day to obtain accurate estimates of epigenetic age. Peripheral blood samples were collected continuously every 3 hours for 24 hours from a 30 year old caucasian male. Collection started at circadian time 8 (CT8), corresponding to 8AM local time. Methylation profile obtained using Illumina Infinium EPIC Human Methylation Beadchip. The microarray experiment was performed in technical triplicates. Sample Neu30yo_ZT20_replicate1 was removed as outlier prior to normalization and is not included in the processed data.