Nativity, Neighborhoods, and Body Composition in the Sacramento Area Latino Study on Aging

Globally, obesity influences the risk of many major chronic diseases. Our study examines the association between individual nativity and neighborhood level concentration of immigrants with 10-year changes in weight, body mass index (BMI), and waist circumference (WC) among older Latinos.

The Sacramento Area Latino Study on Aging (SALSA) is a population-based prospective study of community-dwelling older adults of Mexican origin (baseline ages 58-101 years). The primary outcome was repeated measures of weight over a 10-year period for 1,628 respondents. Nativity was defined by participants' reported place of birth (US-born or Latin American foreign born). Neighborhood immigrant concentration was measured as the percentage of foreign born at census tract level (2000 US Census). We used linear mixed models with repeated measures of weight, height, BMI, and WC as dependent variables (level 1), clustered within individuals (level 2) and neighborhood migrant concentration (level 3).

Foreign born (FB) respondents had lower baseline weight than the US-born (mean, 160 vs. 171 lbs, p < .0001). Over time, weight differences between the FB and the US-born decreased by 1.7 lbs/5 years as US-born weight decreased more rapidly. We observed a significant interaction between individual nativity and neighborhood immigrant concentration (p = .012). We found similar patterns for BMI, but did not find statistically significant differences in WC trajectories.

Our study observed significant differences by foreign born vs. US nativity in baseline weight/BMI and in their trajectories over time. Additionally, we found weight/BMI differences in neighborhood immigrant concentration for the FB, but not for the US-born.