Chinese Americans represent the largest subgroup of Asian Americans, and over 76% of Chinese Americans are foreign-born. It is now well-documented that immigration to the US leads to increased risk for various chronic diseases. For example, rates of type 2 diabetes in Asian Americans rise to converge with, or even exceed, rates in the US white population, as the prevalence of diabetes in Chinese Americans (~12-13%) is higher than the rates of 4-7% observed in US whites, despite their relatively low prevalence of obesity. The increased diabetes risk observed among Chinese immigrants has been primarily attributed to changes in diet and weight gain following immigration, but these changes can only partially explain disparities in disease risk. Models of immigrant health suggest that the stress of adapting to life in a new country has a considerable impact on physical health. However, few studies have considered the psychosocial impact of immigration upon biomarkers of health and disease risk. Chinese immigrants experience considerable acculturative stress, social isolation (e.g., due to language barriers, separation from family), an racial discrimination following immigration, factors that may contribute to poorer overall health among Asian Americans via activation of signaling pathways that link the immune system and metabolism. These pathways are driven in part by neutrophils and, in particular, the secretion of neutrophil elastase (NE), which can impair insulin signaling and boost insulin resistance. At present, these pathways are not well-characterized in human populations, but a greater understanding of inflammatory processes more broadly, and of NE specifically, could lead to new therapeutic approaches for preventing diabetes in Chinese immigrants, a relatively non-obese population. Therefore, guided by a comprehensive biobehavioral model of immigrant health, we propose to conduct a longitudinal study of US Chinese immigrant men and women to address the following specific aims:
Aim 1 : To examine whether psychosocial factors (e.g., acculturative stress, social isolation, discrimination) are associated with markers of type 2 diabetes risk over time;
Aim 2 : To examine whether the association between psychosocial factors and diabetes risk markers is mediated by inflammatory pathways, including NE secretion;
and Aim 3 : To identify key variables (i.e. gender, length of US residence) that may moderate the association between psychosocial factors and inflammation in this immigrant population. In sum, the proposed project offers one of the first systematic opportunities to assess the independent and synergistic contributions of psychosocial and behavioral factors on novel biologic pathways underlying diabetes risk in US Chinese. Study findings will increase our understanding of the complex pathways underlying the health trajectories observed among US immigrants and provide an unprecedented opportunity to identify new pathways for early intervention or prevention in this understudied population that experiences significant health transition upon migration.
The experience of Chinese immigrants represents an especially informative context within which to explore complex pathways underlying stress, social isolation, inflammation, and health behaviors, particularly as they relate to diabetes risk n this rapidly growing population. Data from the proposed research may identify new targets for diabetes prevention (e.g., neutrophil elastase inhibitors) or point to the need for integrating community- and individual-level approaches for reducing psychosocial risk factors, resulting in new approaches for early intervention or prevention in this understudied population that experiences significant disparities in diabetes risk and prevalence.
|Fang, Carolyn Y; Tseng, Marilyn (2018) Ethnic density and cancer: A review of the evidence. Cancer 124:1877-1903|
|Fang, Carolyn Y; Boden, Guenther; Siu, Philip T et al. (2015) Stressful life events are associated with insulin resistance among Chinese immigrant women in the United States. Prev Med Rep 2:563-567|