Project Summary
Sexual minorities have significantly greater risk for obesity, asthma, diabetes, cardiovascular disease,
and some cancers compared to heterosexuals. A key driver of these health disparities is chronic stress related
to stigmatization. Compounding this, racial and ethnic sexual minorities have complex intersecting identities
and experiences of stress that may exacerbate negative health outcomes relative to non-Hispanic White
sexual minorities. Chronic stressors can affect the immune system by both increasing inflammation and
impairing cellular immunity, a pattern causally predictive of risk for acute illness, chronic disease, and mortality.
Funded by NICHD and fielded during the pandemic, the National Couples’ Health and Time Study
(NCHAT) includes 5,157 US adults 18-60 years of age, with oversamples of Black, Latinx, and Asian
individuals. With 2,230 (43.2%) identifying as gay, lesbian, bisexual, or other identifies, NCHAT is the only
population-representative study with a fully-powered subsample of sexual minorities in the US. Capitalizing on
the extraordinary opportunity to address the empirical gap in data on stress biology among sexual minorities,
particularly those with intersecting identities, we added a pilot biological data collection (dried blood spots;
DBS) to NCHAT to create the NCHAT Stress Biology Study (NCHAT-BIO). Biological data collection is
complete, but samples are yet to be assayed. In this R21, we will assay these samples to measure
inflammation (interleukin-6, C-reactive protein) and cellular immune function (Epstein-Barr virus reactivation).
In a diverse cohort of 763 NCHAT participants, we will address these empirical aims:
Aim 1: Delineate differences in immune regulation among sexual minorities versus
heterosexuals. Hypothesis: Sexual minorities will exhibit greater inflammation and poorer cellular immune
function with differential effects among lesbian, gay, and bisexual women and men. Aim 2: Examine effects
of stigma, discrimination, and intersectionality on biomarkers of immune dysregulation within a
minority stress framework. Hypotheses: Experiences of stigma and discrimination will predict greater
inflammation and poorer cellular immune function with stronger effects among sexual minorities and, in
particular, sexual minority participants of color. Aim 3: Identify modifiable behaviors and treatable
psychological factors linking stress with immune dysregulation. Hypotheses: Modifiable health behaviors
(substance use, exercise, diet) and treatable psychological factors (depression, anxiety, sleep disturbance) will
mediate the link between sexual minority stress with immune dysregulation, presenting targets for intervention.
NCHAT-BIO offers a uniquely comprehensive and methodologically rigorous investigation of stress
biology among sexual minorities in the US, permitting novel tests of mechanisms linking stress and health
within a minority stress framework. This R21 will support a future R01 addressing longitudinal changes in
stress biology in the NCHAT cohort.
