br Discussion In a sample of individuals

Discussion In a sample of individuals drawn from four urban centers with large numbers of Hispanics/Latinos, we found that US-born individuals had higher scores of AL than their foreign-born counterparts, with differences less pronounced at ages 55 or older. The association persisted in both men and women, across all Hispanic backgrounds, and was independent of selected social factors and health behaviors. The robustness of this finding is further confirmed by the fact that the nativity differences remained unchanged with other measures of AL and was similar across Hispanic backgrounds. Among the foreign-born, we found that greater duration of US residence and younger ages at immigration were related to higher levels of AL. Results from this large population-based study are consistent with those among Mexican Americans (Crimmins et al., 2007; Kaestner, Pearson, Keene, & Geronimus, 2009; Peek et al., 2010), and extends these findings to US Hispanic/Latinos of other heritage backgrounds. Our data support the healthy immigrant effect, a widely documented and well-established phenomenon in which recent immigrants demonstrate health advantages over demographically similar native-born individuals (Lara, Gamboa, Kahramanian, Morales, & Bautista, 2005). While our data showed that unhealthy behaviors such as cigarette smoking and physical activity were associated with high scores of allostatic load, nativity differences persisted after adjustment for these factors, consistent with prior studies (Crimmins et al., 2007; Kaestner et al., 2009). Proposed alternative explanations for the healthy immigrant effect include selective migration, whereby the healthiest individuals of their respective countries of origin self-select to migrate to a remote and unfamiliar labor market (Bostean, 2013). Given that data on potential emigrants and non-emigrants from participants’ countries of origin are not available in the present study, selective ap-1 cannot be ruled out. Consistent with the notion that newer immigrants’ health advantages erode over time, we observed higher AL scores with longer duration in the US and with younger age at immigration. Findings from NHANES (1988–1994) similarly showed a health advantage among Mexican Americans who immigrated at older ages (Kaestner et al., 2009). Moreover, higher AL among those with longer time spent in the US is supported by a large study of Mexican Americans living in Texas that found nativity differences even after adjusting for social factors and health behaviors (Peek et al., 2010). Among immigrants, longer duration of US residence (>10 years) has been associated with obesity and obesity-related conditions (Goel, McCarthy, Phillips, & Wee, 2004). Exposure to severe challenges and stressors associated with migration and the adoption of a new culture could lead to chronic dysregulation of hypothalamic-pituitary-adrenal axis activity (Mangold, Mintz, Javors, & Marino, 2012; Sapolsky, 2004), with downstream effects on multiple physiological systems. US-born Hispanics/Latinos consistently had the highest AL scores. Assuming that newer immigrants come with a health advantage and lose that advantage through a process of acculturation to levels comparable of the native born population, it\'s conceivable that individuals who have already adopted the host culture (US born) would no longer exhibit such health advantage. This is consistent with previous reports using NHANES data (Kaestner et al., 2009; Peek et al., 2010). However, exposure to stressors associated with acculturation might not be the only factor that drives our associations. In addition, the process of acculturation is complex and may be different for each of the Hispanic groups from different countries of origin. Longitudinal studies will be needed to address these questions, which we plan to conduct in future studies using the HCHS/SOL cohort. The nativity-AL relationship was, however, less pronounced at older ages. This may also reflect an unfavorable influence of increasing acculturation to the US over time among migrants (Antecol & Bedard, 2006), or could also be explained by differences between younger and older individuals in the burden of health conditions and use of medical care. Older individuals are more likely to receive health benefits from the health care system, and the US-born are more likely to take advantage. This may confer a variety of benefits to older US-born Hispanic/Latino persons or among those who have longstanding residence in the US and who therefore have better access to medical and social services. On the other hand, selective survival of older Hispanics with lower AL may offer a competing explanation. Additionally, older individuals with lower levels of AL might have self-selected for inclusion in this study preferentially due to a more favorable health status relative to their similarly aged peers with higher levels of detrimental markers. Another contributory selection factor often cited is the “salmon effect”, the selective return of less healthier older Hispanic/Latino immigrants to their countries of origin (Turra & Elo, 2008). However, our data show differences in AL by nativity/duration in US among Cuban Americans, who would not have easily returned to their country of origin (Abraido-Lanza, Dohrenwend, Ng-Mak, & Turner, 1999). More studies are thus necessary to identify risk and resilience mechanisms that may explain these differences at older ages.