Fig. 1

Cross-tissue and within-tissue similarity of DNA-methylation measures of aging, cross-sectional physiology, and cognition. This figure depicts intraclass correlation coefficients (ICCs) and 95% confidence intervals of DNA-methylation profile scores developed in blood. The green bars depict the cross-tissue ICCs meta-analyzed across three cohorts (n = 107) in the present study. The orange point estimates depict the ICCs reported in previous studies with duplicate samples of blood collected in the same people, where available. The purple point estimates depict the ICCs reported in previous studies with duplicate samples of saliva collected in the same people, where available. The blood ICC values for PCGrimAge, PCPhenoAge, and DunedinPACE are from Reed et al. (2022) [2], and the ICC value for DNAm-CRP (a marker of chronic inflammation) is from Schmunk et al., 2023 [29]. The saliva ICCs are all from child and adolescent samples, specifically ICCs for PCGrimAge, PCPhenoAge, DunedinPACE, and Epigenetic-g are from deSteiguer et al. (2023) [30], the ICC value for DNAm-CRP is from Raffington et al. (2022) [17], and DNAm-BMI (body mass index) is from Raffington et al. (2023) [16]. “Accel.” denotes first- and second-generation methylation measures of aging residualized for chronological age to derive biological age acceleration metrics