The US has the world's largest immigrant population. As most arrive from countries with lower prevalence of obesity and related chronic conditions, a common trajectory is for these rates to rise to converge with or even exceed rates in US whites. This rise underlies the development of numerous health disparities among immigrant/ethnic groups. A primary theory to explain the rise in risk is acculturation, but few longitudinal studies on acculturative and health trajectories have been conducted among immigrants, and trajectories are also likely to be heterogeneous: Acculturation may be limited in ethnic enclaves (self-contained neighborhoods with high residential density of immigrants), and ethnic enclaves themselves differ. Despite a presumed, beneficial `ethnic density effect,' for example, traditional immigrant enclaves can be settings for economic exploitation and curtailed social ties and networks; newer, emerging enclaves outside of city centers might provide the same social resources without the disadvantages of a self-contained, traditional enclave. The experience of Chinese immigrants, among the fastest growing US ethnic groups, is uniquely informative in this regard, exhibiting considerable spatial diversity and variability in chronic disease risk. Indeed, Asian immigrants encapsulate the entire range of risk, from low to high, as a result of environmental and individual-level factors still to be clarified. Immigrant enclaves offer a framework in which to examine disease risk transitions and to explore the combined roles of acculturative and psychosocial pathways. Towards this end, we propose to study health trajectories in a sample of Chinese immigrants using a longitudinal design to capture changes in acculturation, psychosocial factors, and markers of cardiometabolic risk (CMR). We will recruit a cohort of 600 Chinese immigrants in the Philadelphia region, including residents of traditional, emerging, and non-enclave neighborhoods.
Specific aims are to: (1) Compare CMR of immigrants in three neighborhood types (traditional, emerging, and non-enclaves); and (2) Explore pathways that may mediate enclave effects on health ? in particular, acculturative and psychosocial factors. Data collection will include interviews (including acculturation and measures of psychosocial stress and social resources); 4 days of dietary recalls; anthropometry; blood pressure; and blood samples for assessing risk markers including triglycerides, high-density lipoprotein cholesterol (HDL-C), and fasting glucose. Overall, we seek to determine whether and how conditions in one context set a better trajectory for immigrants, or underlie the development of future health disparities. Our model challenges two primary and widely held beliefs: that US Chinese immigrants are a low risk population, and that enclave residence uniformly provides health benefits that keep immigrants at low CMR. The proposed work will allow for a direct comparison across enclaves (distinguishing between traditional and emerging enclaves) and non-enclaves, and will characterize the extent of CMR in the US Chinese population ? a growing, increasingly segregated, and understudied segment of the US population.
The proposed project will contribute to a greater understanding of health trajectories among Chinese immigrants across different neighborhood settings, which will enable identification of the most vulnerable individuals and communities for outreach, and the neighborhoods in which preventive programs might have the greatest impact. Study findings will not only extend current theory on ethnic density and immigrant health, but also inform the development of community-level interventions to reduce cardiometabolic risk and health disparities in this large and growing segment of the US population.
