Life-Course Predictors of Ultrasonic Heel Measurement in a Cross-sectional Study of Immigrant Women from Southeast Asia

Few studies address chronic disease risk for Southeast Asians in the United States. In 1999, the authors conducted a cross-sectional study of bone mineral density (BMD) estimated from ultrasonic calcaneal measurements in women born in Southeast Asia who then lived in Chicago, Illinois. The study addressed three questions: Do Southeast-Asian women have relatively low BMD? What factors before and after immigration are associated with BMD? Are factors that reflect the childhood/adolescent environment equally associated with BMD for postmenopausal and premenopausal women? An interviewer-administered bilingual questionnaire collected immigration, reproductive, and lifestyle data from 213 women (aged 20--80 years) born in Vietnam, Cambodia, or Laos. The authors found that the estimated mean BMD of postmenopausal Southeast-Asian women was lower than the reference values for White women. Four summary indicators of childhood/adolescent environment were predictive of higher BMD: more years of education, earlier age at menarche, lower height, and coastal birth; these indicators were more strongly associated with BMD for premenopausal (multiple-partial R(2) = 0.21) than postmenopausal (R(2) = 0.06) women. Young-adult exposures (e.g., early first pregnancy and age at immigration) and proximal lifestyle factors (e.g., smoking, physical inactivity, vegetarian diet, and betel nut use) were also assessed as potential predictors of BMD.