Abstract A125: Factors associated with differences in sleep patterns across the life course in a population-based study

Purpose: Shorter sleep duration has been linked to multiple breast cancer risk factors, (e.g., increased adiposity), that are disproportionately more prevalent among individuals with lower socioeconomic status. The role of sleep patterns on disparities in breast cancer (BC) remains unclear. We examined the individual and joint associations of race and household poverty with sleep patterns across the life course in a population-based sample of young women, < 50 years of age. Methods: Data are from 1,381 control participants in the Young Women’s Health History Study (YWHHS), a population-based case-control study of invasive BC among non-Hispanic Black (NHB) and non-Hispanic White (NHW) women aged 20-49 years residing in Metropolitan Detroit and Los Angeles County, 2010-2015. From in-person interviews, we assessed usual day sleep duration in childhood (9 years), young adulthood (25 years) and adulthood (1 year before study enrollment) and the weighted percentage of participants meeting U.S. sleep duration recommendations of 9+ hours for children and 7+ hours for both young adults and adults by race (NHB/NHW) and household poverty (< vs. > 250% federal poverty line). Multivariable linear and logistic regression models for complex survey data were used to estimate associations between race, household poverty and sleep patterns. Results: The percentage of women meeting sleep recommendations declined slightly with age from 84.9% in children to 80.0% in young adults and 78.8% in adults, with similar trends across racial and socioeconomic groups. NHB women reported 0.32 fewer hours of sleep in childhood compared to NHW women (p=0.008), with no sleep duration differences by race at subsequent ages (all p>0.35). NHB women were less likely than NHW women to meet sleep duration recommendations as children (OR=0.55, 95% 0.55-0.56), young adults (OR=0.60, 95% 0.59-0.61), and adults (OR=0.63, 95% 0.62-0.64). Similarly, those with higher household poverty were less likely to meet sleep recommendations as children (OR=0.59, 95% 0.58-0.60) and young adults (OR=0.91, 95% 0.90-0.93) but were slightly more likely to meet sleep recommendations as adults (OR=1.02, 95% 1.01-1.04). We did not observe any race by poverty interaction, however, among NHW women, those with lower household poverty were more likely to meet sleep duration recommendations at all ages. In contrast, NHB women with lower household poverty were slightly less likely to meet recommendations across the life course. Conclusion: Our findings suggest racial and socioeconomic differences in meeting sleep duration recommendations, particularly in childhood and early adulthood. Given the consistent evidence linking shorter sleep duration in childhood to BC risk factors (i.e., increased adiposity and chronic inflammation), differences in sleep patterns may partially contribute to racial and socioeconomic disparities in breast cancer. Evidence from our study suggests addressing socioeconomic and structural inequities that impact sleep duration may help to mitigate breast cancer disparities. Citation Format: Kelly A. Hirko, Chris C. Cho, Margaret Y. Tovar, Dorothy R. Pathak, Ann S. Hamilton, Ann G. Schwartz, Ellen M. Velie. Factors associated with differences in sleep patterns across the life course in a population-based study [abstract]. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr A125.