Abstract WP119: The Influence of Ancestral and Geographic Factors on Intracerebral Hemorrhage Risks Among Africans and Americans

Background: We investigated whether risk factors for intracerebral hemorrhage (ICH) among Indigenous Africans (IA) would vary in prevalence and effect compared with self-reported African, Hispanic, and White Americans by comparing data from two independent population-based case-control studies conducted in West Africa and the United States of America Methods: We compared ICH risk factors common to the Stroke Investigative Research and Educational Network (SIREN: 1,100 case-control pairs) and the Ethnic/Racial Variation of Intracerebral Hemorrhage (ERICH: 999 case-control pairs African Americans, 998 case-control pairs, Hispanic Americans, 1000 case-control pairs, white Americans) studies. Ethnicity/Race was self-reported. The effect measure of interest is the odds ratio (OR). To test for differences in the effects of the risk factors between the SIREN IA study population and each of the ERICH study populations, a test for heterogeneity was computed using the R program, metagen (version 4.9-6). Results: ICH occurred at a younger age among IA (54.3±13.4 years), African Americans (58.0±12.7), and Hispanic Americans (58.9±14.3), compared to white Americans (69.1±13.9). The largest distinction was for hypertension, where IA exhibited a much larger risk of ICH than the American study population [OR 67.02, 95%CI (33.30 – 134.85); African American OR 3.71, 95%CI (2.53 – 5.44); Hispanic OR 3.55, 95%CI (2.54 – 4.92), White OR 2.69, 95%CI (1.95 – 3.69).] Current alcohol use exhibited increased risk in IA [OR 2.24, 95%CI: 1.36 – 3.67], but not in African Americans [OR 0.63, 95%CI: 0.46 – 0.86], Hispanic [OR 0.87, 95%CI: 0.65 – 1.17], and White Americans [OR 0.51, 95%CI: 0.38 – 0.69]. Conclusion: Identical or comparable risk factors do not consistently result in the same disease risk across different cultures and regions. Therefore, to improve our understanding of the genetic determinants and biological pathways driving ICH risk, it is crucial to study multiple populations, including IA, while accounting for the influence of environmental and social factors.