Table 1. Reproducibility and age correlations of DNAm based surrogate biomarkers.

Correlation ( r )	Training (N=1731)			Test (N=625)
	Observed biomarker	Age		Observed biomarker	Age
DNAm based surrogate
adrenomedullin	0.65	0.63		0.38	0.64
beta-2-microglobulin	0.62	0.83		0.43	0.85
CD56	0.86	0.17		0.36	0.17
ceruloplasmin	0.56	0.04		0.49	-0.02
cystatin-C	0.58	0.81		0.39	0.83
EGF fibulin-like ECM protein1	0.59	0.72		0.41	0.87
growth differentiation factor 15	0.74	0.71		0.53	0.81
leptin	0.68	0.06		0.35	0.05
myoglobin	0.50	-0.04		0.38	0.03
plasminogen activator inhibitor 1	0.69	0.19		0.36	0.16
serum paraoxonase/arylesterase 1	0.57	-0.22		0.51	-0.22
tissue Inhibitor Metalloproteinases 1	0.43	0.92		0.35	0.90
smoking pack-years	0.79	0.17		0.66	0.13

The table reports the correlation coefficients between the observed marker (i.e. observed plasma protein level or self-reported smoking pack-years) and its respective DNAm-based surrogate marker in 1) the FHS training data and 2) the FHS test data. Each of the DNA-based surrogate biomarkers (rows) leads to a correlation r > 0.35 in both training and test datasets (columns 2 and 4). DNAm-based pack-years is highly correlated with the self-report pack-years in both training and test datasets (r ≥ 0.66). The table also reports the correlation coefficients between the DNAm-based surrogate biomarkers (rows) and chronological age in the FHS training and test data (columns 3 and 5).