Abstract Body: Background: Although Black women are known to have higher hypertension rates than White women, longitudinal investigations of racial disparities in accelerated hypertension onset and the role of neighborhood factors in shaping these differences are severely limited.

Methods: We used data on 15,354 women in the REasons for Geographic and Racial Differences in Stroke (REGARDS) national longitudinal cohort study to quantify racial disparities in accelerated hypertension onset and to examine the degree to which these disparities vary across levels of neighborhood (i.e. census tract) socioeconomic disinvestment. Participants were recruited between 2003-2007 (mean age=64 years, SD=9.5) and followed prospectively. Age of hypertension onset was based on age at self-reported physician diagnosis or measured high blood pressure (≥140mm/Hg systolic or ≥90mm/Hg diastolic). Neighborhood disinvestment (low, moderate, high) was determined using a summary score of six socioeconomic indicators from U.S. Census Bureau data. We used Weibull accelerated failure time models with age as the time-scale accounting for left, interval, and right censoring to estimate racial differences in age of hypertension onset. We adjusted our estimates for individual-level sociodemographic factors, health-related behaviors, and neighborhood clustering.

Results: We found that Black women acquired hypertension a median of 9.4 years earlier than White women (95% Confidence Interval (CI): -10.0, -8.9), independent of individual-level sociodemographic factors. Black-White inequities in accelerated hypertension onset persisted across levels of neighborhood disinvestment. After additionally accounting for census-tract clustering, in neighborhoods with low disinvestment, Black women had hypertension a median of 9.1 years earlier than White women (95% CI: -10.1, -8.0). Within highly disinvested neighborhoods, hypertension occurred a median of 7.7 years earlier (95% CI: -8.8, -6.6) in Black compared to White women.

Conclusion: Our findings highlight that accelerated hypertension onset experienced by Black women persists regardless of neighborhood contexts, underscoring the need to investigate structural determinants earlier in the life-course to address health inequities more effectively.