Abstract 16: County-Level Racial Residential Segregation and Sedentary Behavior in US Adults

Introduction: Sedentary behavior (SB) is highly prevalent and shows an increasing trend in United States (US) adults, resulting in adverse health outcomes, such as cardiovascular disease, cancer, and diabetes. Yet, potential environmental determinants of SB, including racial residential segregation, remain understudied. Hypothesis: County-level segregation will be associated with sedentary time in a nationwide sample of US adults, and this relationship will be moderated by sex. Methods: We analyzed data from 2637 US adults aged 20-75 years (mean age [45.1 years], female [50.6%] from the population-based AmeriSpeak panel in 2019. Participants completed the Activities Completed over Time in 24-hours (ACT24) previous-day recall, a validated population-level measure of total daily SB (hours/day). County segregation was expressed as the isolation index at the county level for non-Hispanic (NH) White, NH Black, and Hispanic adults (vs all other races/ethnicities). The isolation index ranges from 0 to 1, with a higher value indicating higher segregation and therefore, a higher average probability of contact among residents of the minority group and, thus, a lower probability of contact among residents of the minority group and all other races/ethnicities. We used survey-weighted linear regression models to assess the relationships of race-specific isolation index with time spent in SB, adjusting for age, sex, marital status, education, occupation, household income, body mass index, census region, and county-level poverty. Additionally, we stratified these relationships by sex. Results: Overall, US adults reported a mean of 9.5 hours/day of sedentary time. Counties with higher NH White isolation showed a significant inverse relationship with sedentary time (β = -1.52, 95% confidence interval [-2.75, -0.29], p = 0.017). Counties with higher NH Black isolation showed a non-significant inverse relationship with sedentary time (β = -0.30 [-2.53, 1.94], p = 0.790), and counties with higher Hispanic isolation showed a non-significant positive relationship (β = 0.32, [-1.64, 2.28], p = 0.743). In sex-stratified analysis, only NH White isolation among White females showed a significant inverse relationship with sedentary time (β = -2.14 [-4.19, -0.09], p = 0.041). Conclusions: NH White adults, particularly females, residing in more segregated counties reported less sedentary time in this population-based nationwide sample of US adults. SB was not strongly associated with isolation for NH Black and Hispanic adults. Future studies could aim to replicate (or not) our findings with larger samples of underrepresented minority populations and further explore potential mechanisms for sex related variation in the association between residential segregation and sedentary behavior.