Abstract MP023: Changes in Systolic Blood Pressure Differs by Immigration History in a Cohort of Older Mexican Americans

Abstract

Background: Studies on immigrant health suggest that foreign-born individuals have better health outcomes than their native-born counterparts due to health selection. However, effects of immigration history on changes in cardiovascular conditions and risk factors are less well understood. Objective and Hypothesis: We examined the association between immigration history and change in systolic blood pressure (SBP). We hypothesized that Mexican Americans born outside the US and immigrated after age 30 (FB30+), would have lower SBP at baseline and have slower increase in SBP compared to people who were born in the US (US-B) or immigrated from Mexico before age 30 (FB<30). Methods: Participants come from the Sacramento Area Latino Study on Aging (n=1789), a longitudinal cohort of community-dwelling older Mexican Americans (mean age=70.6 years); 51% were born in Mexico. Immigration history was categorized as US-B, FB<30, and FB30+. SBP measures were available at baseline and at five follow-ups over ten years. A mixed effects linear model was used to examine the association between immigration history and SBP. Other covariates included gender, education, current hypertension medication use, and baseline measures of age, BMI, and diabetes. Follow up time was defined as time since enrollment. Quadratic time was included to account for non-linear change in SBP. Two interaction terms (immigration history x linear time and immigration history x quadratic time) were included to assess differences in SBP change by nativity. Results: The study included 1598 participants after exclusions. The figure shows the predicted average SBP by immigration history over the study period, derived from the mixed linear model. Compared to US-B, the FB<30 and FB30+ experienced an average of 7.3 (95% CI 2.0-12.7) and 7.9 (95% CI 2.2-13.5) mmHg increase in SBP over the study period, respectively. Conclusions: In contrast to current literature, immigrants appeared to be at greater risk for adverse cardiovascular risk factors.