title: Immigrant assimilation and BMI and waist size: a longitudinal examination among Hispanic and Chinese participants in the multi-ethnic study of atherosclerosis.
abstract: OBJECTIVE
  US birth and longer length of US residence among the foreign-born have been linked to higher anthropometric measures. However, previous studies have been cross sectional and few have examined heterogeneity by ethnic group. Cross-sectional findings that show immigrant weight converging to US-born levels with longer time in the United States imply that immigrants' weight is increasing at a faster rate relative to US-born individuals. Prospective studies are necessary to confirm this pattern.
  
  
  METHODS
  Using longitudinal data from 1,486 Hispanic and 802 Chinese adults aged 45-84 years in the Multi-ethnic Study of Atherosclerosis, we examined whether foreign-born participants experienced greater increases in BMI and waist circumference (WC) than the US-born over a median follow-up of 5 years. We also investigated heterogeneity in these associations by Hispanic subgroup.
  
  
  RESULTS
  Among Hispanics and Chinese, the foreign-born had a lower adjusted mean BMI and WC at baseline than the US-born, but there were no significant differences in BMI or WC change over time. There was heterogeneity by Hispanic subgroup: despite small baseline nativity differences in WC, foreign-born Mexican Hispanics had a greater annual mean increase in WC over time compared to US-born Mexican Hispanics (mean difference in annual change = 0.28 cm, P = 0.03). There were no nativity differences in the rate of WC increase over time among non-Mexican Hispanics. Foreign-born Mexican Hispanics also experienced a faster rate of WC increase compared to foreign-born non-Mexican Hispanics (mean difference in annual change = 0.24 cm, P = 0.01).
  
  
  CONCLUSIONS
  Longer time in the United States, examined prospectively, may only be linked to adverse anthropometric changes in some immigrant groups.
authors.affiliation: Center for Social Epidemiology and Population Health, Department of Epidemiology, University of Michigan, Ann Arbor, Michigan, USA. ssalb@unc.edu
authors.forename: Sandra S
authors.initials: SS
authors.lastname: Albrecht
authors.forename: Ana V
authors.initials: AV
authors.lastname: Diez Roux
authors.forename: Namratha R
authors.initials: NR
authors.lastname: Kandula
authors.forename: Theresa L
authors.initials: TL
authors.lastname: Osypuk
authors.forename: Hanyu
authors.initials: H
authors.lastname: Ni
authors.forename: Sandi
authors.initials: S
authors.lastname: Shrager
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D050197:Atherosclerosis / Q000208:ethnology*; D015992:Body Mass Index; D001835:Body Weight; D003430:Cross-Sectional Studies; D054242:Emigrants and Immigrants; D005260:Female; D005500:Follow-Up Studies; D006630:Hispanic or Latino; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D014481:United States / Q000453:epidemiology; D055105:Waist Circumference