Sexual minority stress and epigenetic aging.

Lesbian, gay, bisexual, transgender, and queer/questioning (LGBTQ + ) individuals have poorer mental and physical health than heterosexuals, and bisexuals fare worse than individuals who identify as lesbian and gay. However, data on stress biology among sexual minorities are critically insufficient. The current pilot study utilized data from 32 bisexual women - a subset of the National Couples' Health and Time Study - who completed questionnaires and provided blood samples to index biological aging from DNA methylation data (DunedinPACE, GrimAge2). The mean DunedinPACE score was 1.13 (SD = 0.18), which outpaced chronological aging by 13 % (p < 0.001). Likewise, bisexual women in this sample were, on average, 8.67 (SD = 5.96) years older biologically per GrimAge2 as compared to their chronological age. In covariate adjusted models, those reporting greater internalized homonegativity exhibited significantly greater epigenetic age acceleration (GrimAge2: p = 0.01; DunedinPACE: p = 0.041). Those who reported more frequent anti-bisexual experiences also showed accelerated GrimAge2 (p = 0.023). In contrast, those who reported stronger identity centrality (p = 0.017), stronger identity affirmation (p = 0.029), and more friend support (p = 0.018) - a critical type of support for LGBTQ + individuals - had slower GrimAge2. Depressive symptoms, anxiety and loneliness were not associated with GrimAge2 or DunedinPACE. Results suggest that bisexual women are at risk for accelerated aging, and those who have less internal and external affirmation of their sexual identity may be most at risk.