Abstract Body (Do not enter title and authors here): Background: Sexual minority (e.g., gay/lesbian, bisexual) adults are at a higher risk of hypertension than heterosexual adults. Minority stressors, which are chronic psychosocial stressors related to one’s sexual minority identity, are hypothesized to influence these hypertension disparities among sexual minorities. However, these associations have not been formally tested.

Aims: We sought to examine sexual identity differences in daily minority stressors (i.e., experienced and anticipated discrimination) and blood pressure (BP) between sexual minority and heterosexual siblings of the same sex.

Hypothesis: We hypothesized that: 1) participants who reported greater daily minority stressors would have higher systolic BP (SBP), and 2) the associations of daily minority stressors with SBP would be stronger among sexual minority siblings.

Methods: We conducted a 14-day daily diary study to examine the associations of personally experienced and anticipated (i.e., expectations of experiencing discrimination) discrimination with SBP among sexual minority adults and their heterosexual siblings with no history of hypertension or cardiovascular disease. Home SBP was assessed each morning and evening for 14 consecutive days following AHA guidelines. Daily minority stressors were assessed via structured diaries. We used multilevel linear models to estimate associations between daily minority stressors with same-day morning and evening SBPs. We then included interaction terms between each minority stressor and sexual identity.

Results: The sample included 40 participants (20 sibling pairs) with a mean age of 26.7 (±5.35) years. Approximately 75% were assigned female sex at birth, 68% were White (68%), and 15% were Latinx. Sexual minority adults reported had higher same-day evening SBPs (B=2.16, p=0.03) than their heterosexual siblings. Participants who reported higher anticipated discrimination had higher same-day evening SBP (B=0.68, p<0.001) and next-morning SBP (B=2.16, p=0.03). Daily experienced discrimination was not associated with SBP. Sexual identity did not moderate the associations between minority stressors with SBP.

Conclusions: This is the first study to document that daily anticipated discrimination and having a sexual minority identity are linked with elevations in home SBP. Findings suggest there is a need for larger studies to investigate mechanisms linking anticipated discrimination with elevations in SBP and potential differences by sexual identity.