Abstract P2025: Incident stroke in unstably housed women: the role of cocaine and alcohol co-use

Background: Sex and social determinants of health predict stroke, yet few studies focus exclusively on women at high social risk. Understanding associations between stroke and modifiable risk factors that are disproportionately common in high-risk populations may aid in tailoring primary and secondary prevention services. We sought a better understanding of the association between polysubstance use, with an emphasis on stimulant use, and stroke in women who experience homelessness and unstable housing (WEHUH). Methods: We recruited WEHUH from San Francisco community-based venues to participate in a cohort study. We identified incident stroke from electronic health records during the 2.5-year study period and up to two years following study completion. We then assessed associations with baseline study factors, including social determinants of health, toxicology-confirmed use of multiple substances, and traditional stroke risk factors. We used multiple logistic regression to determine independent relationships between study factors and incident stroke. Results: Among 243 participants, health records showed that nine (3.7%) had incident strokes. After adjusting for BMI, hyperlipidemia, and opioid use, cocaethylene--a biomarker signaling alcohol and cocaine concurrent co-use-- had a particularly strong association with incident stroke (OR 4.37; 95% CI 1.05-18.13). Conclusion: Stroke risk factors such as age and race were not strongly associated with incident stroke among WEHUH, but cocaethylene and opioids were. This suggests two possible opportunities for prevention in an environment where opioid use is already closely monitored. First, women reporting cocaine and alcohol co-use should be counseled about the especially harmful effects of this substance combination on their cerebrovascular health. Second, the utility of cocaethylene to assess stroke risk in high-risk populations may be currently underestimated.