Racial Disparities in Blood Pressure Trajectories of Preterm Children: The Role of Family and Neighborhood Socioeconomic Status

Abstract

Racial disparities in cardiovascular disease mortality in the United States remain substantial. However, the childhood roots of these disparities are not well understood. In the current study, we examined racial differences in blood pressure trajectories across early childhood in a sample of African-American and European-American low-birth-weight preterm infants. Family and neighborhood socioeconomic status (SES), measured at baseline, were also examined as explanations for subsequent group disparities. Analyses focused on 407 African-American and 264 European-American children who participated in the Infant Health and Development Program, a US longitudinal study of preterm children born in 1985. Blood pressure was assessed on 6 occasions between the ages of 24 and 78 months, in 1987-1992. Across this age range, the average rate of change in both systolic and diastolic blood pressure was greater among African-American children than among European-American children. Neighborhood SES explained 29% and 24% of the racial difference in the average rate of change in systolic and diastolic blood pressure, respectively, whereas family SES did not account for group differences. The findings show that racial differences in blood pressure among preterm children emerge in early childhood and that neighborhood SES accounts for a portion of racial disparities.

Keywords: African Americans; blood pressure; early childhood; health status disparities; infant, low birth weight; preterm birth; residence characteristics; social class.

Figure 1.

Estimated systolic blood pressure trajectories for African-American (AA) and European-American (EA) children (models 2–4), Infant Health and Development Program, 1987–1992. Black lines represent AA children, and gray lines represent EA children. Solid lines represent fitted plots from model 2, which included the following variables: level 1—linear slope, quadratic slope, blood pressure measurement technique, child's cooperation during blood pressure reading, and body mass index; level 2—race, sex, treatment group, birth weight, gestational age, fetal growth restriction, Neonatal Health Index, gestational weight gain, trimester in which prenatal care began, smoking during pregnancy, obesity, heart condition or hypertension, gestational diabetes, preeclampsia or eclampsia, and maternal age. Dashed lines represent fitted plots from model 3, which added income-to-needs ratio and maternal education at level 2. Dotted lines represent fitted plots from model 4, which added neighborhood mean income at level 3.

Figure 2.

Estimated diastolic blood pressure trajectories for African-American (AA) and European-American (EA) children (models 2–4), Infant Health and Development Program, 1987–1992. Black lines represent AA children, and gray lines represent EA children. Solid lines represent fitted plots from model 2, which included the following variables: level 1—linear slope, quadratic slope, blood pressure measurement technique, child's cooperation during blood pressure reading, and body mass index; level 2—race, sex, treatment group, birth weight, gestational age, fetal growth restriction, Neonatal Health Index, gestational weight gain, trimester in which prenatal care began, smoking during pregnancy, obesity, heart condition or hypertension, gestational diabetes, preeclampsia or eclampsia, and maternal age. Dashed lines represent fitted plots from model 3, which added income-to-needs ratio and maternal education at level 2. Dotted lines represent fitted plots from model 4, which added neighborhood mean income at level 3.