UCSF

Immigrants in the United States make up 13% of the total population and have been a critical component in the country’s population growth. Previous studies have shown that immigrants tend to perform better in overall mortality and other health conditions, a phenomenon commonly known as the healthy immigrant effect. However, the growing literature on immigrant health has been primarily cross-sectional. A longitudinal perspective is needed, particularly since age of immigration or duration of stay in the receiving country can influence risk factors for adverse health conditions. Mexico is the most common country of origin for immigrants, and Hispanic adults carry significant cardiovascular burden due to their high levels of cardiovascular risk factors.

This dissertation focuses on two particular risk factors: low density lipoprotein cholesterol (LDL-C) and blood pressure, which are both strongly associated with myocardial infarction (MI) and stroke. In the first two chapters, a variable for immigration history is used and incorporates both nativity and age of immigration. The first chapter examines the role of immigration history on longitudinal changes in elevated LDL-C. The second chapter evaluates how immigration history affects trajectories of systolic blood pressure over time. Analyses also examine the associations between immigration history, LDL-C, and systolic blood pressure with MI/stroke. Chapter 3 extends the work of Chapter 2 by assessing the differences by nativity status in systolic and diastolic blood pressure trajectories before and after MI/stroke.

Analyses used data from the Sacramento Area Latino Study on Aging, a cohort study of community-dwelling older adults of Mexican-origin. Mixed effects and Cox proportional hazards models were used to address the research questions. Results indicate that participants born outside the United States and immigrated in later adulthood (i.e. after age 20) had poorer cardiovascular risk factors over time: they were more likely to have elevated LDL-C and had a faster rate of increase in systolic blood pressure. While risk of incident MI/stroke did not differ between each group of immigration history, there were nativity-related differences in blood pressure trajectories before and after MI/stroke. These results provide evidence to reevaluate previous perspectives on immigrant health and the healthy immigrant effect.