Associations Between Longitudinal Loneliness, DNA Methylation Age Acceleration, and Cognitive Functioning.

TitleAssociations Between Longitudinal Loneliness, DNA Methylation Age Acceleration, and Cognitive Functioning.
Publication TypeJournal Article
Year of Publication2023
AuthorsLynch, M, Arpawong, TEm, Beam, CR
JournalThe Journals of Gerontology, Series B, Psychological Sciences and Social Sciences
ISSN Number1758-5368
KeywordsAged, Aging, Biomarkers, Cognition, DNA Methylation, Humans, Loneliness, Longitudinal Studies

OBJECTIVES: Loneliness may influence aging biomarkers related to cognitive functioning, for example, through accelerated DNA methylation (DNAm) aging.

METHODS: In the present study, we tested whether six common DNAm age acceleration measures mediated the effects of baseline loneliness and five different longitudinal loneliness trajectories on general cognitive ability, immediate memory recall, delayed memory recall, and processing speed in 1,814 older adults in the Health and Retirement Study.

RESULTS: We found that baseline loneliness and individuals who belong to the highest loneliness trajectories had poorer general cognitive ability and memory scores. Only DNAm age acceleration measures that index physiological comorbidities, unhealthy lifestyle factors (e.g., smoking), and mortality risk-mediated effects of baseline loneliness on general cognitive ability and memory functioning but not processing speed. These same DNAm measures mediated effects of the moderate-but-declining loneliness trajectory on cognitive functioning. Additionally, immediate and delayed memory scores were mediated by GrimAge Accel in the lowest and two highest loneliness trajectory groups. Total and mediated effects of loneliness on cognitive functioning outcomes were mainly accounted for by demographic, social, psychological, and physiological covariates, most notably self-rated health, depressive symptomatology, objective social isolation, and body mass index.

DISCUSSION: Current findings suggest that DNAm biomarkers of aging, particularly GrimAge Accel, have promise for explaining the prospective association between loneliness and cognitive functioning outcomes.

Citation Key13689
PubMed ID37718577
PubMed Central IDPMC10699733
Grant ListT32 AG000037 / AG / NIA NIH HHS / United States
R01AG063949 / AG / NIA NIH HHS / United States
AARF-17505302 / ALZ / Alzheimer's Association / United States