Stress and spirituality in relation to HPA axis gene methylation among US Black women: results from the Black Women's Health Study and the Study on Stress, Spirituality and Health.

Background: Few epigenetics studies have been conducted within the Black community to examine the impact of diverse psychosocial stressors and resources for resiliency on the stress pathway (hypothalamus-pituitary-adrenal axis). Methods: Among 1000 participants from the Black Women's Health Study, associations between ten psychosocial stressors and DNA methylation (DNAm) of four stress-related genes (NR3C1, HSDB1, HSD11B2 and FKBP5) were tested. Whether religiosity or spirituality (R/S) significantly modified these stress-DNAm associations was also assessed. Results: Associations were found for several stressors with DNAm of individual CpG loci and average DNAm levels across each gene, but no associations remained significant after false discovery rate (FDR) correction. Several R/S variables appeared to modify the relationship between two stressors and DNAm, but no identified interaction remained significant after FDR correction. Conclusion: There is limited evidence for a strong signal between stress and DNAm of hypothalamus-pituitary-adrenal axis genes in this general population cohort of US Black women.