Abstract P3080: Factor IX and Incident Hypertension in Black and White Adults: The REasons for Geographic and Racial Differences in Stroke (REGARDS) Cohort

Background: A significant fraction of Americans are diagnosed with hypertension. Prior studies have shown Black adults experience a disproportionate amount of this burden. Certain biomarkers of thrombosis are associated with a greater risk of hypertension. Factor IX is a marker of thrombosis. Whether higher factor IX correlates with an increased risk of incident hypertension or explains some of the disproportionate burden faced by Black adults is not fully known. Methods: We included Black and White participants from the REasons for Geographic and Racial Difference in Stroke (REGARDS) study, excluding those with prevalent hypertension, missing factor IX level, or covariates of interest. Modified Poisson regression estimated risk ratios (RR) for incident hypertension by higher factor IX tertiles. A mediation analysis was performed using inverse odds ratio weighting to assess whether racial differences in hypertension risk could be attributed to factor IX levels. Results: A total of 1,824 participants were included, (55% female and 24% Black race), with 36% of participants developed incident hypertension. Higher factor IX levels were seen in Black participants with a mean of 110% vs 105% for White participants (p=0.0018). As shown in the Table, there was a greater risk of incident hypertension by higher factor IX tertile in all models. Mediation analysis did not demonstrate factor IX level mediated hypertension risk in any model. Conclusions: In this prospective study of Black and White adults without prevalent hypertension, higher factor IX was associated with a greater risk of developing hypertension, after adjusting for known confounders. A mediation analysis did not indicate that the excess burden of hypertension experienced by Black adults could be explained by factor IX level.