From Migration to Methylation: Assessing the Impact of U.S. Immigration on Adolescent Cardiovascular Health Using Methylation Clocks

Abstract

Having to adapt to a foreign land, immigrants in the United States often experience elevated stress levels. Migration is a complex psychosocial process with long-lasting health consequences. Paradoxically, immigrants arrive healthier than U.S.-born individuals, but this advantage declines over time. As chronic stress can induce epigenetic changes such as hypermethylation, I hypothesize that children of immigrant mothers exhibit altered DNA methylation patterns and worse cardiovascular outcomes compared to children of U.S.-born mothers. This thesis investigates whether maternal nativity predicts cardiovascular health and biological aging in children, using data from the Future of Families and Child Wellbeing Study and its cardiovascular subsample (FFCVH). Cardiovascular health was assessed at Year 22 using the American Heart Association’s Life’s Essential 8 (LE8) score; biological aging was measured at Years 9 and 15 using six DNA methylation clocks: Horvath Pan-Tissue, Horvath Skin and Blood, DNAmPhenoAge, DNAmGrimAge, DunedinPoAm, and DunedinPACE. A 2:1 propensity score matching approach compared LE8 and DNA methylation age acceleration (EAA). Multivariable regressions tested whether maternal nativity predicted LE8, whether LE8 predicted EAA, and whether LE8 mediated the nativity–EAA relationship. Children of immigrant mothers had significantly higher LE8 scores, indicating better cardiovascular health. Higher LE8 scores were associated with lower EAA across multiple clocks, with stronger effects at Year 15. While maternal nativity alone did not consistently predict EAA, it became significant in adjusted models for select clocks. These findings suggest maternal nativity shapes cardiovascular health and contributes to differences in biological aging in the second generation.