Pilot study of DNA methylation, molecular aging markers and measures of health and well-being in aging

Relations of DNA methylation markers to other biological aging markers and to psychosocial, behavioral, and health measures remain unclear. The sample included 23 participants (n = 11 cases with psychiatric diagnoses and n = 12 controls without current or lifetime psychiatric disorder), balanced by age and sex. Genomic DNA was extracted from blood samples; the following were performed: genome-wide DNA methylation assay using Illumina 850k methylationEPIC; PCR assays for relative telomere length (RTL) and mitochondrial DNA copy number (mtCN). Exposures were: case status; depression and anxiety symptoms; psychosocial support; subjective and objective cognition. Outcomes were: DNA methylation age (DNAm age); RTL; mtCN; extrinsic and intrinsic epigenetic age acceleration (EEAA and IEAA). Stronger correlation with chronological age was observed for DNAm age (ρ = 0.86; p < 0.0001) compared to RTL (ρ = −0.53; p < 0.01); mtCN was not correlated with age. DNAm age was more strongly correlated with behavioral and health variables than RTL or mtCN; e.g., correlations with DNAm age: body mass index (ρ = 0.36; p = 0.10); smoking pack-years (ρ = 0.37; p = 0.08); physical activity (ρ = −0.56; p = 0.01); alcohol intake (ρ = 0.56; p = 0.01). DNAm age was inversely correlated with psychosocial support (ρ = −0.42; p = 0.048) and Modified Mini-Mental State score (ρ = −0.44; p = 0.01). Anxiety, psychosocial support, and objective cognition were significantly related to accelerated aging; depression and subjective cognition were not. In conclusion, DNAm age correlated more strongly with chronological age and key psychosocial, behavioral, and health variables than RTL or mtCN. Signals for associations with epigenetic aging were observed for psychosocial and neurobehavioral variables.