Heterogeneity in the Association between Acculturation and Adiposity among Immigrants to the United States.

U.S. birth and longer length of U.S. residence among immigrants have been associated with a higher risk of obesity. However, few studies have examined this pattern longitudinally or examined heterogeneity in this relationship. Doing so may inform how social processes that relate to different immigrant integration patterns impact obesity. Using prospective data from the Multi-Ethnic Study of Atherosclerosis (MESA) and repeated, cross-sections from the National Health and Nutrition Examination Survey (NHANES), this dissertation examined: 1) differences in rates of waist circumference (WC) increase among U.S. and foreign-born Hispanic and Chinese adults (MESA); 2) the role of the neighborhood environment in moderating the relationship between nativity/length of U.S. residence and WC among Hispanic and Chinese adults (MESA); and 3) variation over time in the relationship between nativity/length of U.S. residence and body mass index (BMI) and WC among Mexican-American adults (NHANES). Results demonstrated that longer exposure to the U.S. context does not have the same implications for weight gain for all immigrants. In MESA, Hispanic and Chinese immigrants did not have a greater rate of increase in WC over time relative to the U.S.-born; however, foreign-born Mexican Hispanics experienced an accelerated rise in WC compared to both U.S.-born Mexican Hispanics and foreign-born non-Mexican Hispanics. Hispanic immigrants living in neighborhoods with greater healthy food availability had a lower mean WC than immigrants in neighborhoods with poor healthy food availability. Among Chinese, more recent immigrants living in more walkable neighborhoods increased in WC more slowly than recent immigrants in less walkable areas. Among Mexican-Americans in NHANES, there was a graded relationship between longer length of U.S. residence and higher BMI and WC, and this relationship did not change substantially between 1988-1994 and 2005-2008. However, there were important variations in this patterning by gender and by socioeconomic status. The share of immigrants in the U.S. population continues to grow. A more nuanced understanding of the impact of the U.S context on the health of this vulnerable group will inform public health interventions, and address troubling health disparities.Ph.D.Epidemiological ScienceUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/89621/1/ssalb_1.pd

Ethnic Differences in Body Mass Index Trajectories from Adolescence to Adulthood: A Focus on Hispanic and Asian Subgroups in the United States

BackgroundCompared to whites, U.S. Hispanics have higher obesity rates; U.S. Asians have lower rates. However Hispanics and Asians are each comprised of several ethnic subgroups that differ with respect to country of origin, immigration history, and geographic distribution across the U.S. Among adolescents, ethnic differences in obesity have been previously reported, but no studies have examined longitudinal change in body mass index (BMI) by Hispanic and Asian subgroup category to understand when and why these disparities emerge, especially during the critical transition between adolescence and adulthood.MethodsUsing nationally-representative, longitudinal data from 1355 Hispanics (Mexican, Puerto Rican, Cuban, Central/South American, Other Hispanic), 520 Asians (Chinese, Filipino, Other Asian), and 5061whites from the National Longitudinal Study of Adolescent Health (Waves II–IV: 1996–2009), we used linear mixed spline models to examine whether Hispanic and Asian adolescent subgroups shared the same BMI trajectories as whites as they aged into adulthood. We also investigated the role of social and behavioral factors in explaining race/ethnic differences.ResultsAmong Hispanics, Mexican and Puerto Rican-origin individuals exhibited faster increases in BMI both in adolescence and in adulthood and these patterns were not attributable to the measured social and behavioral factors. There was also evidence of emerging disparities in Cuban males, and in Central/South Americans relative to whites. In contrast, Chinese, Filipino, and Other Asian adolescents had significantly lower BMI and slower BMI increases in adulthood compared to whites. In models adjusted for social and behavioral factors, Chinese-white and Other Asian-white differentials remained unexplained.ConclusionsAggregate estimates of Hispanics and Asians mask important heterogeneity in BMI. A better understanding of weight dynamics early in the life course can inform how and when disparities emerge to better target prevention efforts

Socioeconomic gradients in body mass index (BMI) in US immigrants during the transition to adulthood: examining the roles of parental education and intergenerational educational mobility

Despite comparatively lower socioeconomic status (SES), immigrants tend to have lower body weight and weaker SES gradients relative to U.S.-born individuals. Yet, it is unknown how changes in SES over the life-course relate to body weight in immigrants versus US-born individuals

Exploring secular changes in the association between BMI and waist circumference in Mexican-origin and white women: a comparison of Mexico and the United States

BMI and waist circumference (WC) tend to be highly correlated, but changes in lifestyle behaviors may promote greater accumulation of abdominal fat for the same BMI in recent years. We examined secular shifts in BMI and WC distributions, and investigated whether WC for a given BMI has changed over time among Mexican-origin women in Mexico and the U.S., and in U.S. white women as a comparison

Immigrant status and cardiovascular risk over time: results from the Multi-Ethnic Study of Atherosclerosis

Despite cross-sectional evidence that foreign-born United States (US) residents often have better health than US-born residents of similar race/ethnicity, we know little about overall cardiovascular risk progression over time among immigrants as they age in the US

Immigrant assimilation and BMI and waist size: A longitudinal examination among hispanic and chinese participants in the multi‐ethnic study of atherosclerosis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99611/1/oby20104.pd

Racial and Ethnic Residential Segregation, the Neighborhood Socioeconomic Environment, and Obesity Among Blacks and Mexican Americans

We used cross-sectional data on 2,660 black and 2,611 Mexican-American adult participants in the National Health and Nutrition Examination Survey (1999–2006) to investigate the association between metropolitan-level racial/ethnic residential segregation and obesity and to determine whether it was mediated by the neighborhood socioeconomic environment. Residential segregation was measured using the black and Hispanic isolation indices. Neighborhood poverty and negative income incongruity were assessed as mediators. Multilevel Poisson regression with robust variance estimates was used to estimate prevalence ratios. There was no relationship between segregation and obesity among men. Among black women, in age-, nativity-, and metropolitan demographic-adjusted models, high segregation was associated with a 1.29 (95% confidence interval (CI): 1.00, 1.65) times higher obesity prevalence than was low segregation; medium segregation was associated with a 1.35 (95% CI: 1.07, 1.70) times higher obesity prevalence. Mexican-American women living in high versus low segregation areas had a significantly lower obesity prevalence (prevalence ratio, 0.54; 95% CI: 0.33, 0.90), but there was no difference between those living in medium versus low segregation areas. These associations were not mediated by neighborhood poverty or negative income incongruity. These findings suggest variability in the interrelationships between residential segregation and obesity for black and Mexican-American women

Field validation of food outlet databases: the Latino food environment in North Carolina, USA

OBJECTIVE: Obtaining valid, reliable measures of food environments that serve Latino communities is important for understanding barriers to healthy eating in this at-risk population. DESIGN: The primary aim of the study was to examine agreement between retail food outlet data from two commercial databases, Nielsen TDLinx (TDLinx) for food stores and Dun & Bradstreet (D&B) for food stores and restaurants, relative to field observations of food stores and restaurants in thirty-one census tracts in Durham County, NC, USA. We also examined differences by proportion of Hispanic population (</≥23·4 % Hispanic population) in the census tract and for outlets classified in the field as 'Latino' on the basis of signage and use of Spanish language. SETTING: One hundred and seventy-four food stores and 337 restaurants in Durham County, NC, USA. RESULTS: We found that overall sensitivity of food store listings in TDLinx was higher (64 %) than listings in D&B (55 %). Twenty-five food stores were characterized by auditors as Latino food stores, with 20 % identified in TDLinx, 52 % in D&B and 56 % in both sources. Overall sensitivity of restaurants (68 %) was higher than sensitivity of Latino restaurants (38 %) listed in D&B. Sensitivity did not differ substantially by Hispanic composition of neighbourhoods. CONCLUSIONS: Our findings suggest that while TDLinx and D&B commercial data sources perform well for total food stores, they perform less well in identifying small and independent food outlets, including many Latino food stores and restaurants

Sustainable Management of Rangelands: An Assessment of Invasion Cover Trajectories and Their Contribution to Invasion Management in Marigat Sub-County, Kenya

Invasive alien species have complex spatiotemporal patterns of spread beyond geographical and jurisdictional boundaries. This calls for a coordinated management approach that is spatially explicit, extends beyond individual plot levels, and incorporates land users’ perceptions and decisions. This study, therefore, aims at assessing spatiotemporal invasion trajectories of the invasive tree Prosopis juliflora in Baringo County, Kenya, and evaluating their possible relation to land users’ management decisions. Pre-classified land cover data over a seven-year time period (1988–2016) were reclassified based on the presence or absence of P. juliflora and integrated into ArcGIS to produce P. juliflora cover trajectories for analysis. The spatiotemporal analysis of Prosopis invasion dynamics yields trajectories that can be linked to underlying land users’ management decisions. Areas that remained free of Prosopis since their first clearance were primarily areas where the invasion would cause the highest loss in terms of income or opportunity costs; areas that were never cleared since they were first invaded tended to be areas where no one could be personally held accountable for their management, while the abandonment of management followed by re-invasion appeared to be linked to different drivers, including diversification of livelihoods and lower market prices for horticultural products. Our findings indicate that invasion trajectories are useful in informing existing management strategies to adopt context-based invasive species management practices. The study recommends scaling up the trajectory analysis approach to be replicated in large-scale invasion management strategies. Since it requires considerable finances and time to conduct such analyses on raw satellite imagery, we suggest further research on how to simplify the approach to make it easily and efficiently replicable for large-scale applications