Intersectional stigma, health behaviors, and allostatic load among sexual and gender diverse people.

Sexual and gender diverse (SGD) people face significant health disparities linked to chronic stigma exposure. Yet, the biological mechanisms underlying these inequities remain unexplored. This project examines how lifetime intersectional discrimination influences allostatic load (AL) -the cumulative biological 'wear and tear' of chronic stress-and explores the role of health behaviors (smoking, alcohol use, drug use, sleep quality and physical activity) as potential mediators in this pathway. Our team recruited 357 adults separated into 7 subgroups stratified by gender identity and sexual orientation. Blood samples and biometrics were collected from each participant and analysed to create a composite AL index incorporating 16 biomarkers across multiple physiological systems. Psychosocial variables including intersectional discrimination experiences and health behaviors were derived from validated questionnaires. Results show that intersectional discrimination experiences were positively associated with AL after controlling for age, indicating that both major discriminatory events and cumulative daily experiences independently contribute to physiological dysregulation through enacted stigma and discrimination exposure. Additionally, both gender identity and sexual orientation relate to differential AL patterns, with masculine-spectrum people (cisgender and transgender men) and sexual minority men (bisexual and gay men) showing the highest AL levels. Contrary to our hypothesis, health behaviors did not mediate the relationship between discrimination and AL, suggesting that discrimination may exert direct biological effects through stress response systems without requiring negative behavioral pathways. These findings provide further support for recognition of the impacts of structural and social determinants of health among SGD communities and the need for policy changes that protect against structural inequities.