LAUSR

Introduction: Among immigrant populations in the United States (US), proxy measures of acculturation such as length of time (LOT) in the US are associated with poor cardiometabolic health. Nevertheless, limited evidence exists among Black immigrants, and the role of nativity has not been fully explored. We aimed to evaluate the association between LOT in the US and cardiometabolic outcomes among US Black adults. Methods: The National Health Interview Survey (NHIS) is an annual representative survey of non-institutionalized US civilians. We combined data from 2016 - 2018 and included all Black adults (N = 10,034). LOT was defined as the number of years participants were reported to have lived in the US. Outcomes of interest were obesity, hypertension, diabetes, and high cholesterol, each defined based on self-report of ever being diagnosed by a medical doctor. We used logistic regression models to determine whether LOT in the US was associated with cardiometabolic health factors overall and by nativity subgroups - US-born non-Hispanic, Hispanic, African-born, and Caribbean/Central American (CA)-born groups. Models were adjusted for age, sex, race, education, marital status, health insurance status, and family income-to-poverty ratio. All analyses accounted for the NHIS complex survey design. Results: Our study population was 81% US-born non-Hispanic, 5% Hispanic (both foreign- and US-born), 6% African-born, and 6% Caribbean/CA-born groups. Among Black adults overall, compared with those born in the US, the odds of obesity were 70% lower (OR: 0.30, 95%CI: 0.22 - 0.41) for the foreign-born individuals with <15 years in the US, and 44% lower (OR: 0.56, 95%CI: 0.46 - 0.70) for those with ≥15 years. In addition, compared with those born in the US, the odds of hypertension were lower by 67% (OR: 0.33, 95%CI: 0.23 - 0.47) for the foreign-born individuals with <15 years, and by 46% (OR: 0.54, 95%CI: 0.43 - 0.68) for those with ≥15 years in the US. In subgroup analyses, Caribbean/CA-born individuals with <15 years in the US had 68% lower odds of obesity (OR: 0.32, 95%CI 0.13 - 0.76) and 66% lower odds of hypertension (OR: 0.36, 95%CI 0.15 - 0.86) compared to those with ≥15 years, but no significant effect was observed among African-born or Hispanic black adults. Conclusion: Among US black adults, shorter LOT in the US was associated with more favorable cardiometabolic health with differential associations by nativity. This heterogeneity suggests a need to examine the implications of acculturation in the context of the specific population of interest.