Stress, Epigenetics and Aging

Project Summary There is extensive evidence that socioeconomic status (SES) and social stressors shape the development of numerous chronic conditions and aging-related illnesses. However, the processes through which SES and social stress affect biological processes related to aging and disease development have not been fully elucidated, particularly at the cellular level. This is important to investigate among African Americans who have higher mortality, shorter lifespan, and experience a disproportionate burden of disease than whites. Research examining associations between stressors and biological aging processes have been predominately cross- sectional in nature and have included predominately racially and ethnically homogenous samples. No prior studies have assessed the independent and cumulative impact of SES and stress at multiple time points across the life course in relation to biomarkers of aging (e.g. telomere length, DNA methylation age). Furthermore, little is know as to whether behavioral and psychological factors mediate the association between stress and biological aging processes, and whether forms of resilience (e.g., coping response, social support) may modify these associations. We propose to leverage existing data from the Disparities (DISPAR) study to examine the relationship between stressors and resilience across the life course in relation to biological aging processes. The DISPAR study conducted a 50-year follow-up of women who participated in a pregnancy cohort between 1959 and 1957 in Alameda County, California. Subsets of offspring were followed at ages 5 y, 9-11 y, 15-17y, and 50 years. The DISPAR sample includes a representative subsample (n=605) of these children interviewed as adults (mean age of 50 years), 42% African-American and 50% female. Validated measures of negative life events, discrimination, caregiving stress, mental health, social support, and coping mechanisms among others were collected. In addition, anthropometric measures, blood pressure and a blood sample were collected. For this study (N=372), we propose to assay existing stored blood collected at age 50 for biomarkers of biological aging (telomere length, methylation age). We will examine the role of childhood and adult SES and psychosocial stressors (e.g. child adversity, caregiving stress, job stress, racial discrimination) on telomere length and methylation age in adulthood. Additionally, we propose to examine behavioral (e.g. physical activity, smoking) and psychological (e.g. distress) responses to stress as potential mediators of these associations, and positive and negative coping factors as potential modifiers of the associations between SES, stress and biological processes. Given that half of our sample is African-American, we will have the opportunity to assess how stress, resilience-based factors, and associated biological aging processes differ by race. Completion of this project would allow us to elucidate important biological, genetic, and epigenetic pathways that help explain how stress and resilience shapes population health disparities among aging populations.